Flexible Solutions for Your Supervisory Control and Data Acquisition Needs. SCADA System Selection Guide

Transcription

1 Flexible Solutions for Your Supervisory Control and Data Acquisition Needs SCADA System Selection Guide

2 How to Use This Booklet This book assumes you have an understanding of the: control-system requirements of the application locations of the sites that you will be controlling If you are: Then: unfamiliar with SCADA follow sections in sequential order choosing an A-B SCADA system for the first time familiar with A-B products and want to see see page 4-1 available master and remote stations see page 5-1 interested in third-party products see page A-1 unfamiliar with terminology see the Glossary, located at the end of this booklet Related Publications Use these manuals as necessary: Title: Publication Number: Automation Systems Catalog Enhanced and Ethernet PLC Programmable Controllers User Manual Classic PLC-5 Family Programmable Controllers Hardware Installation Manual 1785 PLC-5 Family Programmable Controllers Quick Reference PLC-5 Instruction Set Reference Manual KE DH+ Communications Interface Module User Manual SLC 500 and MicroLogix 1000 Instruction Set Reference Manual SLC 500 Modular Hardware Style Installation and Operation Manual DH-485/RS232C Interface Module User Manual MicroLogix 1000 Programmable Controllers User Manual Logix5550 Controller User Manual Logix5550 Controller Programming Manual

3 Table of Contents Chapter 1 Your SCADA System Solutions What is SCADA? Variety of Applications Flexibility Products Designed for SCADA Applications Control System Experience Support Selecting System Components Selection Worksheet What To Do Next Chapter 2 Choosing a Telemetry Network Overview Choose a Topology Choose a Transmission Mode Choose a Link Media Choose a Protocol What To Do Next Chapter 3 Choosing Data Communication Equipment Overview Choose a Telephone Modem Analog Dial-up Modem Analog Leased-Line Modems Digital Leased-Line ISUs Telephone Modem and ISU Installation Guidelines Choose a Radio Transmission System Licensing Radio Modem Types Radio Modem Installation Guidelines Choose a SatelliteTransmission System Choose Power Line Modems What To Do Next Allen-Bradley Motors

4 toc ii Table of Contents SCADA System Selection Guide Chapter 4 Choosing a Device for a Master Station Overview A submaster station controls remote sites within a region Choose a VAX- or UNIX-based Computer Choose a Personal Computer-Based Master Station Use RSView32 software as a master station Use RSView32 software as an operator interface Choose a Programmable Controller-based Master Station Choose a Data Concentrating Submaster Station Choose a Data Routing Submaster Station Needed Equipment Installation Guidelines What To Do Next Chapter 5 Choosing a Device for a Remote Station Third-Party Supplier Contact Information Overview Choose a Device MicroLogix 1000 or SLC 5/0(x) Processor-based Remote Stations. 5-2 PLC-5 Processor-based Remote Stations Logix5550 Processor-based Remote Stations Needed Equipment Installation Guidelines What To Do Next Appendix A Contact List A-1

5 Chapter 1 Your SCADA System Solutions What is SCADA? SCADA is an acronym for Supervisory Control and Data Acquisition. Use this book as a guide for choosing SCADA system components. If you re already familiar with SCADA, go to page 1-8. SCADA systems let you monitor and control various remote functions and processes by using serial communication links between master and remote locations Ethernet or or Master Station RS-232 RS-232 RS-232 Modem Modem Modem Remote Station Pump Station Remote Station Gas Metering Station Modem Clarifying Deck Remote Station Pump Station Modem Remote Station Waste Treatment Plant Allen-Bradley Motors

6 1-2 Your SCADA System Solutions Variety of Applications Using only a few remote points Monitor and record the physical properties of the oil flowing through a pipeline across the Alaskan tundra Occurring within a facility Automatically retrieve or store parts within a factory by using radio or power-line modems 41122

7 Your SCADA System Solutions 1-3 Monitoring and controlling a city s fresh-water supply Monitor and pump the water supply for a city or a small town 1000 ft. 20 miles DH+ Modem Microwave Transceiver with Modem Modem RF Radio with Modem RF Radio with Modem Microwave Transceiver with Modem SLC 5/04 Processors PLC-5/11 Processor MicroLogix 1000 Processor RSView32 Software Collector Wells Booster Station Reservoir Water Plant Logix5550 Processor Allen-Bradley Motors

8 1-4 Your SCADA System Solutions Monitoring and controlling thousands of I/O points distributed over a large geographical area Monitor and control offshore oil or gas pumping platforms from the land-based refinery. Integrate the data you gather into the overall process for producing and shipping the final petroleum product Computer Workstation Remote Station DCE Server Computer Workstation Ethernet PLC-5/40E Remote Station Remote Station Remote Station Remote Station Remote Station Remote Station Remote Station Unloading Storage Facility Mainline Pump Station Refinery Storage Refinery Storage Mainline Pump Station Storage/Delivery Facility Storage Tanks Storage Tanks Storage Tanks Storage Tanks Unloading Dock Metered Truck Rack 41124

9 Your SCADA System Solutions 1-5 Flexibility Allen-Bradley has developed a close relationship with several companies who supply SCADA-related hardware and software. Through the Encompass Program, we reference hardware and software companies that provide you with additional products to meet your application needs. We review each company to make certain it provides the quality and service you deserve. Refer to the Encompass Program Product Directory for the latest information. With products supplied by Encompass Program members, use Allen-Bradley master and remote stations with other protocols, such as: Modbus Teledyne-Brown Control Applications (CA) DNP 3.0 Use data communication equipment supplied by Encompass Program members to connect to a variety of communication media, such as: telephone radio power lines Products Designed for SCADA Applications Key features built into Allen-Bradley products help provide a one-stop SCADA solution. Choose from many sizes of programmable controllers for master station and remote station control needs. Select one or more Logix5550 processors in a rack with one or more Ethernet, ControlNet and/or DH+ communication modules to fit your most demanding master station and remote station requirements. Select an Enhanced PLC-5 processor from six available memory sizes to fit your medium to large master station and/or remote station requirements in single or redundant configurations. Select a SLC 5/03, SLC 5/04 or SLC 5/05 processor to fit your master station and/or remote station requirements for small to medium applications. Select a MicroLogix 1000 (with or without analog I/O) to fit your small remote station applications. Integral communication means less equipment to buy. Logix5550, Enhanced PLC-5, SLC 5/03, SLC 5/04, SLC 5/05 and MicroLogix 1000 processors provide built-in support for serial communication links. Select an Ethernet PLC-5 or SLC 5/05 processor not only for built-in serial communication but also for built-in Ethernet connectivity that uses standard TCP/IP protocol. Allen-Bradley Motors

10 1-6 Your SCADA System Solutions Use the Logix5550 processor in a ControlLogix Gateway to bridge a large MIS application via Ethernet to master station control. Fulfill your host computer software and master station needs by using Rockwell Software RSView32 software. With RSView32 MMI software and RSLinx 2.0 Communications Server software, your personal computer can be a master station and an operator interface to your system. Using the RSView32 Active Display option, multiple workstations can access and share a common database across a local area or wide area Ethernet network. Add RSLogix programming software, and the RSView32 workstation can become the system programming terminal for both local and remote stations. Using Allen-Bradley DF1 half-duplex protocol provides these advantages: You do not have to program the master station to read blocks of data from each remote station to determine if the remote station has new data. Get data from remote stations by just polling them. Remote stations can collect data on their own and have the message blocks waiting to send when the master station polls it. Perform remote station-to-remote station messaging through the master station without any special ladder logic in the master or increased processing time. Program remote stations over the telemetry network without interrupting the master station's normal control and data acquisition functions.

11 Your SCADA System Solutions 1-7 Control System Experience Our many years of control system experience and a broad product line can provide you with a total system solution. Choose from our many: push-button and switches programmable controllers I/O modules operator interfaces development software packages industrialized computers specialized PLC -based hardware and software that support process control, motion control, ac/dc drives, and vision systems Support A world-wide technical support network helps answer your questions. Allen-Bradley Technical Support provides help for you over the telephone or at your control sites. Allen-Bradley uses local distributors to provide quick turn-around on your orders and local support. While no one knows your Allen-Bradley products better than Allen-Bradley, no one knows your local situation better than your local Allen-Bradley distributor. Many Allen-Bradley and Rockwell Software product training courses are available. For information about available training programs, contact your local Allen-Bradley sales office or distributor. Allen-Bradley Motors

12 1-8 Your SCADA System Solutions Selecting System Components Each section describes a specific component and presents selection criteria to help you make appropriate choices for your application. To select SCADA system components: or or 1. Choose a telemetry network (if not specified). 2. Choose data communication equipment (DCE). Ethernet 3. Choose a master station and (if necessary) an operator interface. 4. Choose a remote station for the local control site. 3. Master Station RS-232 RS-232 RS For modular processors, select appropriate input/output modules to monitor and control the application. 1. Telemetry Network 2. DCE 4. Remote Station 4. Remote Station 4. Remote Station SLC 5/03 with I/O Modules

13 Your SCADA System Solutions 1-9 Selection Worksheet Use this worksheet as a quick guide to specifying a system. For this component: Choose: See: Record your selection(s): Telemetry Network Data Communication Equipment Master Station Operator Interface Submaster Station topology point-to-point point-to-multipoint multipoint-to-multipoint transmission mode half-duplex full-duplex page 2-2 page 2-3 link media page 2-3 protocol page 2-8 Choose DCEs based on the following: page 3-1 link media transmission requirements diagnostic requirements master and remote station needs application Choose a master station based on the following: functionality required (I/O to scan, amount of data to be collected, operator interface needed) quantity of remote stations protocol being used other application requirements Make sure you have the following: a serial interface the proper equipment for the protocol you are using power for the station Depending on your choice, choose other components you may need: I/O modules and chassis local area network components enclosures Depending on the size of your application, you may need operator interfaces or submaster stations. page 4-1 page 4-8 Remote Stations Choose a remote station based on the following: functionality required quantity of I/O points being controlled power availability space location of the remote station other application requirements Choose control system components: I/O modules and chassis enclosures operator interfaces protocol being used page 5-1 Allen-Bradley Motors

14 1-10 Your SCADA System Solutions What To Do Next See the following chapters for more information on setting up your SCADA system. For more information about: See page: choosing a telemetry network 2-1 choosing data communication equipment 3-1 choosing a device for a master station 4-1 choosing a device for a remote station 5-1 third-party supplier contact information A-1 terminology Glossary

15 Chapter 2 Choosing a Telemetry Network Overview A telemetry network provides the communication pathway in a SCADA system. These components make up a telemetry network: Design the network by choosing each piece. For more information about: choosing topologies 2-2 choosing transmission lines 2-3 choosing link media 2-3 choosing protocols 2-8 See page: Master Station Data Communication Equipment transmit Topology point-to-point DF1 Topology point-to-multipoint Link Media Link Media Link Media transmit Transmission Mode: half-duplex Transmission Mode: full-duplex Protocol: DF1 transmit receive DF1 DF1 receive transmit receive DF1 receive DF1 Protocol: DF1 Remote Station Remote Station Remote Station Remember that an application can have more than one telemetry network. In some critical applications you may want to design a back-up system or recovery procedure for your main network. So, analyze your requirements and select telemetry networks accordingly. Allen-Bradley Motors

16 2-2 Choosing a Telemetry Network Choose a Topology Topology is the geometric arrangement of nodes and links that make up a network. For a SCADA system, choose among these topologies: Topology: Definition: Comments: Point-to-Point generally a 2-wire connection Point-to-Multipoint (multidrop) Communication link between only two stations Either station can initiate communication with the other, or one station can inquire and control the other. station Communication link among three or more stations with one station being a communication arbitrator (master) that controls when the other stations (remote stations) can communicate master modem modem station DTE DCE DCE DTE modem modem modem The stations can be connected by using: cables or permanent public media like leased telephone lines or digital data services temporary connections, such as dial-up lines or microwave, radio, or satellite transmissions Choose this topology if you need a peer-to-peer communication connection, such as a back-up communication link between remote stations at a site and the master station at the control site. Two-wire means that transmission media type uses two wires for signal transmission/reception. Since a public switched telephone network provides a 2-wire connection, the topology used for a dial-up line is 2-wire point-to-point. The stations can be connected by using: permanent public media like leased lines or digital data services atmospheric connections, such as microwave, radio, or satellite transmissions Point-to-multipoint is the main topology for SCADA applications. Four-wire means that transmission media type uses four wires for signal transmission/reception, one pair to transmit and one pair to receive. Private leased lines and digital data services provide four-wire, point-to-multipoint connections. remote remote Multipoint-to- Multipoint Communication link among three or more stations where there is no communication arbitrator (master) and any station can initiate communications with any other station. This is a special radio modem topology that is supported by some suppliers. It provides a peer-to-peer network among stations. a radio modem connection station radio modem station radio modem radio modem station radio modem station

17 Choosing a Telemetry Network 2-3 Choose a Transmission Mode Transmission mode is the way information is sent and received between and/or among devices on a network. For SCADA systems, your network topology generally determines your data transmission mode. If you have chosen this topology: point-to-multipoint Then your transmission mode is: half-duplex Which means: Information is sent in one direction at a time over the link. station A transmit receive receive transmit station B point-to-point multipoint-to-multipoint full-duplex full-duplex (between station and modem) half-duplex (between modems) Information is simultaneously sent and received over the link. station A transmit receive receive transmit station B station A transmit receive receive transmit modem A transmit receive receive transmit modem B transmit receive receive transmit station B Choose a Link Media When choosing a link media, consider such items as the following: data transmission needs of the application remote site and control center locations distance between sites available link media services project budget Allen-Bradley Motors

18 2-4 Choosing a Telemetry Network The types of link media available are: Type: Definition: Public transmission media Public Switched Telephone Network (PSTN); Internationally: General Switched Telephone Network (GSTN) % % The dial-up network is furnished by a telephone company. This telephone line is the one that we use daily and that carries voice and data transmissions. Private Leased Line (PLL) PLL is a dedicated telephone line that is a permanent connection between two or more locations and that is used for analog data transmission. The line is available 24 hours a day. For the line to be used for voice PLL PLL communication, a voice option must be installed. Phone Company Digital Data Service (DDS) DDS is a special wide-bandwidth private leased line that DDS DDS uses digital techniques to transfer data at higher speeds and at a lower error rate than private leased lines. The line is available 24 hours a day. Phone Company Atmospheric media Microwave Radio Microwave radio is a high-frequency (GHz), terrestrial radio transmission and reception media that uses parabolic dishes as antennas. The dishes are usually mounted on towers or on tops of tall buildings, since this is a line-of-sight topology. VHF/UHF Radio VHF/UHF radio is a high-frequency electromagnetic, wave transmission. Radio transmitters generate the signal, and a special antenna receives it. Radio Modem Radio Modem Geosynchronous satellite Geosynchronous satellites use a high-frequency (GHz) radio transmission to route transmissions between sites. The satellite's orbit is synchronous with the earth's orbit (geosynchronous orbit); therefore, the satellite remains in the same position with respect to the earth. Satellites receive signals from and send signals to parabolic dish antennas. Earth Power line With special data communication equipment, you can transmit and receive data over 120V ac or 460V ac power bars within a factory.

19 Choosing a Telemetry Network 2-5 Before choosing a medium, consider these advantages and disadvantages: Type: Advantages/Capabilities: Disadvantages: Equipment Needed: Public Switched Telephone Network % % The media is cost effective for applications that require the following: short, occasional data collection from remote sites that have access to a PSTN a site to call into a central location Often point-to-point applications have a dial-up connection as a back-up to the main link media. The phone company charges you a monthly fee based on use - the number of local connections made and/or the time and distance of each long distance connection. The network supports communications rates of up to 33,600 bps. The network is a 2-wire connection that supports half-duplex modems and 2-wire, full-duplex modems. The topology is point-to-point. Transmission is costly for long, frequent data collection from remote sites. The lines can contain impairments that can cause modems to have error rates of less than 1 error per 1,000,000 bits. The media cannot be used in areas that do not have access to the network, such as an offshore oil or gas well. Time is required to dial and establish each connection. Additional logic is required to automatically initiate a connection. Use standard Bell or Consultive Committee for International Telephone and Telegraph (CCITT) modems. Contact the telephone company for information about connecting to the network. Private Leased Line PLL PLL Phone Company The media is cost effective for applications that require large amounts of data to be frequently collected from remote sites and/or require remote sites to have a constant connection to the master station. Regardless of how much you use the line, the phone company charges you a flat, monthly fee based on the following: distance between sites area of the country type of line conditioning Leased lines have different levels of conditioning, or grades - the higher the grade, the greater the modem data rate that can be supported by the link, and the more the phone company charges for it. The standard, unconditioned line, supports speeds of up to 28,800 bps. Private leased lines provide a 4-wire connection. You can purchase modems that operate the circuit in either half- or full-duplex mode. You can also order a 4-wire multi-drop line. The media cannot be used in areas that do not have access to the network, such as an offshore oil or gas well. The lines can contain impairments that can cause modems to have error rates of less than 1 error per 1,000,000 bits. Use standard Bell or CCITT modems. Contact the telephone company for information about connecting to the network. Allen-Bradley Motors

20 2-6 Choosing a Telemetry Network Type: Advantages/Capabilities: Disadvantages: Equipment Needed: Digital Data Services DDS DDS Phone Company DDS is a digital network that offers higher transmission rates and minimal, if any, line impairments. The media is useful when an application requires very large amounts of data to be transferred between sites and needs a low data error rate. Regardless of use, the phone company charges you a flat, monthly fee based on the following: distance between sites area of the country speed of the integrated service unit (digital modem ) A constant connection exists. Asynchronous communication rates are 2.4k, 4.8k, 9.6k, 19.2k, 38.4k, and 57.6k bps. The network provides a four-wire connection and can be configured in a multi-drop topology. The media is costly for applications not needing to transmit large amounts of data quickly and at a low data error rate. Use standard integrated service unit, ISU (also called a data service unit [DSU] or channel service unit [CSU]). The ISU data rate must match that of the digital data service line, which operates at a fixed rate. Microwave Radio The media links geographically-remote areas that are not accessible by phone lines. A constant connection exists. Transmissions can occur over very long distances over rough terrain. You incur no monthly service fee because you own the equipment. The only expense is operating and maintenance costs. Low transmission delay times exist. The larger bandwidth lets you multiplex many channels over one antenna. Lease circuits from another company who owns their own private microwave circuit. Transmission is limited to a line-of-sight, i.e. you cannot transmit through mountains. Also, the signal can experience distortion and interference. Also, atmospheric conditions (rain, snow, fog) can affect the signal. Most microwave link frequencies are allocated and regulated by the Federal Communications Commission (FCC). In urban areas, fewer data-transmission frequencies are available. You can incur large initial expense for equipment. transmitters receivers parabolic dish antennas repeaters needed to transmit long distances over hills or mountains VHF/UHF Radio The media links geographically-remote areas that are not accessible by phone lines. A constant connection exists. Transmissions can occur over rough terrain and over distances of less than 30 miles. You incur no monthly service fee because you own the equipment. The only expense is operating and maintenance costs. Minimal transmission delay times exist. Use repeaters to extend transmissions over distances larger than 15 miles. Most radio link frequencies are allocated and regulated by the FCC. In urban areas, fewer data-transmission frequencies are available. The signal from 900MHz and above transmitters can experience distortion and interference and can be affected by poor weather conditions. The narrow bandwidth carries only one channel. You incur an initial expense for equipment; less expensive than microwave or satellite. transmitters receivers antennas repeaters needed to transmit longer distances and over hills and mountains

21 Choosing a Telemetry Network 2-7 Type: Advantages/Capabilities: Disadvantages: Equipment Needed: Geosynchronous Satellite Power Line Earth The transmissions can link sites almost anywhere on Earth. A constant connection exists. You incur a monthly service fee. You can lease circuits just like you can lease dedicated telephone lines from a telephone company Rates can be competitive with leased lines, depending on the total distance, remote station locations, and amount of data being transmitted. The media offers high reliability and data integrity. You do not need to group remote sites because the communication media usually is accessible. No need exists for extra cabling The media simplifies design and lowers cost You do not need an FCC license. You can encounter longer transmission delays, measured in seconds rather than milliseconds as for other media. You incur a large initial cost for the satellite dish and supporting equipment. Transmission cannot occur through transformers without bridges. See the vendor for the bridges. With some vendors, speed may be distance limited. access to satellite satellite transmitters Earth-bound receiving parabolic-dish antennas power line or other power delivery media RS-232 interface Allen-Bradley Motors

22 2-8 Choosing a Telemetry Network Choose a Protocol A protocol governs the format of data transmission between two or more stations, including handshaking, error detection, and error recovery. When choosing a protocol, you must select one that best fits your application s: connection topology transmission mode other application requirements, such as connections to existing equipment If your transmission mode is: bidirectional but one direction at a time simultaneously bidirectional Then choose this type of protocol: half-duplex full-duplex If all the control products used in your point-to-multipoint application are A-B products, use the DF1 half-duplex protocol because it provides benefits, such as: remote data table monitoring and online programming by using standard Rockwell Software programming software remote station-to-remote station messaging a more cost-effective solution since the protocol is built into Allen-Bradley products DF1 protocol is an asynchronous, byte-based protocol. You may need to choose a non-df1 protocol if you are: using links, such as satellite or packet radio, that may require software handshaking to communicate expanding an existing system (you are adding A-B remote stations) or specifying a retrofit, which is not using DF1 protocol emulating someone else's product with an A-B programmable controller If you do need to use an alternate protocol, our third-party protocol suppliers provide gateway solutions between A-B devices and devices that communicate by using non-df1 protocols. See the following table for a list of third-party protocol suppliers.

23 Choosing a Telemetry Network 2-9 Table 2.A Use this table to help direct you to a third-party protocol supplier. You can find their addresses in appendix A. Protocol: Supplier: A-B form factor: Installation: master protocols Allen-Bradley DF1 half-duplex DNP 3.0 Emerson FX Drive Honeywell 7800 Burner Control IEC Limitorque Valves MDA Scientific CM4 MDA Scientific System 16 MetOne 215W Modbus ASCII and RTU MTS Level Plus Mycom Compressors Precision Engine Controls SEAbus York Chiller XTACK ProSoft Technology, Inc. Bakersfield, CA I/O chassis slot 1746 I/O chassis slot Install the ProSoft module into a 1771 or 1746 I/O chassis. Communication with the processor takes place across the chassis backplane. Install the ProSoft RTU 5/03 processor with built-in Modbus slave protocol into a 1746 I/O chassis. Modbus slave communication with the processor takes place through channel 0 slave protocols DNP 3.0 IEC Harris 5000/6000 Landis & Gyr 8979F Metasys N2 Modbus ASCII and RTU Systronics (VSAT supported) Teledyne CA Allen-Bradley DF1 half-duplex Caterpillar Gas and Diesel Engine Caterpillar Digital Voltage Regulator Controlotron Danload 6000 Dynalco TM6000 and TEC9000 Modbus ASCII and RTU Omron Host Link Power Measurements Ltd. ACM3720 Reliance Single and Multiple Processor SquareD Sy/Max Systronics MV2 2 TRW S70 2 master protocols Miille Applied Research Company, Inc. Houston, TX I/O chassis slot 1746 I/O chassis slot DIN rail mount Install the MARC module into a 1771 or 1746 I/O chassis and connect via an RS-232 cable to the PLC/SLC (powered off of chassis backplane). DIN rail mount unit connects via 1761-CBL-PMO2 cable to MicroLogix 1000 (powered off of external 24VDC). 1 For the most up-to-date list of available protocols, see supplier web page. 2 Supported on 1771 form-factor only. Allen-Bradley Motors

24 2-10 Choosing a Telemetry Network Protocol: Supplier: A-B form factor: Installation: slave protocols Allen-Bradley DF1 half-duplex Applied Automation OPTROL 2 CDC Type II Conitel 2020 ENRON Modbus ASCII and RTU SCI RDACS 2 Square D Sy/Max Systronics Micromote 2 Tejas Teledyne CA Tenessee Gas Miille Applied Research Company, Inc. Houston, TX I/O chassis slot 1746 I/O chassis slot DIN rail mount Install the MARC module into a 1771 or 1746 I/O chassis and connect via an RS-232 cable to the PLC/SLC (powered off of chassis backplane). DIN rail mount unit connects via 1761-CBL-PMO2 cable to MicroLogix 1000 (powered off of external 24VDC). TRW master protocols Allen Bradley DF1 half-duplex AMOCAMS 2 Avtron Advantage 32 Drive Barber-Coleman Maco Eurotherm Drive/Controller Enraf Nonius Series 858 CIU Fenner Mdrive Fisher DPR Series Controller McQuay Microtech Modbus Powertech Digimax Drive Westinghouse Incom/Impacc Yokogawa YS/XL and UT Real Time Automation Wauwatosa, Wisconsin BAS (SLC) 2760-RB (PLC-5) Firmware/protocol cartridge that plugs into module slave protocols Modbus 1 For the most up-to-date list of available protocols, see supplier web page. 2 Supported on 1771 form-factor only. Once a non-a-b protocol is used, A-B protocol advantages, such as remote station to remote station messaging and online programming, may no longer apply. What To Do Next Record your telemetry network choices on the checklist (page 1-9). You should have defined the: topologies transmission modes link media protocols Go to the next section to choose your data communication equipment.

25 Chapter 3 Choosing Data Communication Equipment Overview Data Communication Equipment (DCE) is the link between a transmission medium and master and remote stations (data terminal equipment or DTE). Data communication equipment includes phone and radio modems as well as microwave and satellite transmission equipment. Choose that data communication equipment appropriate for the communication media you have chosen. Master Station For more information about: See page: choosing a telephone modem 3-2 choosing integrated service units 3-6 choosing a satellite transmission system 3-12 choosing power line modems 3-13 what to do next 3-14 Remote Station Remote Station Remote Station Allen-Bradley Motors

26 3-2 Choosing Data Communication Equipment Choose a Telephone Modem Modems convert digital information from a programmable controller or computer to an analog signal that is compatible with the communication media being used. The signal is then transported to the receiving modem, which converts the analog signal back into a digital one (Figure 3-1). Figure 3.1 In this example, digital data from each DTE is converted to an analog signal for transmission over the communication media. DTE DCE DCE DTE I Two modem technology standards exist to make certain that modems developed by different manufactures are compatible: Bell Type: Consultive Committee for International Telephone and Telegraph (CCITT) Explanation: The Bell standard was the predominant standard in the United States until the break-up of AT&T in the USA. The CCITT standard is the international standard that is now becoming the standard for the USA. Most modems now conform to one or more of the CCITT standards, such as V.32, V.32bis, V.22, etc. In most cases, the two modem types are not compatible. Keep this in mind when choosing modems for stations that are being added to or are retrofits to an existing installation. Compatibility charts exist; consult a modem supplier for more information. Use the selections that you recorded from the previous section, Choosing a Telemetry Network, to answer these questions: What type of link(s) are you using to transmit data (PSTN, private leased line, radio, etc.)? What transmission mode(s) are you using (half-duplex, full-duplex)? What are your network topologies (point-to-point, point-to-multipoint)? Are you using 2-wire or 4-wire lines?

27 Choosing Data Communication Equipment 3-3 Once you know the type of modem, use these criteria to help you choose appropriate models: needed data communication rate requirements of the DTE devices to which you are connecting Do you need asynchronous or synchronous operation? Note: If you are using all A-B DTE devices, choose an asynchronous modem. What interfaces do you need (RS-232, MIL 188, EIA-449, IEEE 488, CCITT V.24)? What other features are required to support your DTEs? required standards (UL, CSA, FCC, etc.) space requirements. Do you need a rack-mounted or stand-alone modem? input-power requirements ambient temperature specifications modem design and operation modem response time Once you have a good idea of the modem type you need, choose a modem based on the many available features and options, which vary by manufacturer. For information about this modem type: See page: Analog dial-up 3-4 Analog leased-line 3-5 Digital leased-line 3-6 Allen-Bradley Motors

28 3-4 Choosing Data Communication Equipment % % If you are using this DTE: Logix5550 processors Enhanced PLC-5 processors SLC 5/03, 5/04, and 5/05 processors RSLinx 2.0 Software 1747-KE 1785-KE 1770-KF KF3 Analog Dial-up Modem Table 3.A lists the modem features that are required by certain A-B DTE devices. Since you may not know the exact programmable controller or computer your application needs, you may need to refer to this table after you have chosen your DTEs to finalize your modem selection. Table 3.A Keep these requirements in mind when choosing analog dial-up modems for A-B DTEs. The DTE needs support for: ASCII strings to configure and control the dial-up modem auto answer capability and hang-up control via the RS-232 DTR signal line Make certain the modem you choose has this feature: AT-command-set support MicroLogix 1000 controllers answer capability only auto answer support configurable to auto answer when DTR (data transmit ready signal) is high and hang-up the current connection when DTR switches from high to low See Table 3.B for a listing of recommended modem suppliers and respective modem models. Table 3.B Use these recommendations to help you choose analog dial-up modems. Consult the vendor for information about their product offerings. Supplier: Maximum Transmission Rate: Modem Model: DATA-LINC Group 28,800 DLM Miille Applied Research Co. Inc , 14,400 and 28,000 DLM4200CP (1746 rack mount) (1771 rack mount) and 1771 rack mount available. 2 Cellular phone compatable.

29 Choosing Data Communication Equipment 3-5 Analog Leased-Line Modems PLL Phone Company PLL Table 3.C describes the type of modem you should choose. Table 3.C Keep these considerations in mind when choosing leased-line modems. For this application: Point-to-point, full-duplex Point-to-multipoint, half-duplex Choose this modem type: any asynchronous, full-duplex 2-wire or 4-wire leased-line modem pair asynchronous, point-to-multipoint operation over a 4-wire or 2-wire leased line Typically these modems have a Master setting for the modem connected to the master station and a Slave setting for the modems that connect to remote stations. For the master station: choose a modem that has the capability of holding the modem carrier high so that no time is lost waiting for the modem carrier to turn on and stabilize whenever the Master modem has data to transmit. For the remote stations: choose a modem that can switch the carrier on and off, whether transmitting or receiving, based on RTS/CTS signal handshaking with the other remote stations. You need to use switched modem carrier since the stations share the same leased-line channel and would jam each other's data transmission attempts if two or more remote station modems set their carriers high at the same time. Using a half-duplex mode virtually guarantees that no two remote stations will attempt to transmit data at the same time. Whether an application uses 2-wire or 4-wire leased lines, choose remote modems that support switched modem carriers. Depending on the speed of the modem you choose, you may need a better conditioned line. A leased-line modem s cost is composed of two principal items: monthly leased-line charges, which are directly proportional to the conditioning or communication rate capability of the leased line modem price, which is directly proportional to the modem's communication rate capability Allen-Bradley Motors

30 3-6 Choosing Data Communication Equipment Therefore, the most efficient system matches the maximum communication rate of the modem to that of the leased line to which the modems are attached. See Table 3.D for a listing of recommended analog leased-line modem suppliers and respective modem models. Table 3.D Use these recommendations to help you choose analog leased-line modems. Consult the vendor for information about their product offerings. Supplier: Transmission Rate: Topology: Modem Model: DATA-LINC Group Miille Applied Research 1200 point-to-point 2 LLM point-to-multipoint 2 point-to-multipoint 5 LLM ,800 point-to-point 5 DLM point-to-multipoint (1746 rack mount) point-to-point 3 4 point-to-multipoint (1771 rack mount) point-to-point (1771 rack mount) 1 1 Dual/redundant modem. 2 4-wire leased line only. 3 2-wire or 4-wire leased line. 4 2-wire maximum transmission rate is 300 baud. 5 2-wire leased line only and 1771 rack mount available. Digital Leased-Line ISUs Integrated Service Units (ISUs) are the modem equivalents for the digital data service lines. You can use the DDS network for point-to-point and point-to-multipoint systems. Two components make up an ISU (Figure 3-2): data service unit (DSU), connects to the RS-232 link DDS Phone Company DDS channel service unit (CSU), transmits the digital signal onto the communication line Figure 3.2 Integrated service units are the DCEs for the digital data service lines. DTE ISU DSU CSU CSU ISU DSU DTE 41140

31 Choosing Data Communication Equipment 3-7 The data rate for the ISU must match that of the DDS line. Some ISUs can operate at multiple rates, but the rate of a DDS line is fixed. Typical asynchronous DDS line speeds are 9600, 19.2k, 38.4k, and 57.6k bits per second. Table 3.E Use these recommendations to help you choose digital leased-line ISUs. Consult the vendor for information about their product offerings. Supplier: Transmission Rate: Topology: Modem Model: DATA-LINC Group 57,600 point-to-point DLM-4300 point-to-multipoint Telephone Modem and ISU Installation Guidelines Telephone modems and ISUs require a telephone-company approved connector. Consult your modem/isu vendor for installation requirements. Choose a Radio Transmission System Radio Modem Radio Modem You can use radio modems for either point-to-point, point-to-multipoint, or multipoint-to-multipoint applications. The primary selection consideration for radio modems is the radio frequency band in which they operate. You can choose among these radio types: Radio Type: Frequency: VHF UHF higher frequency UHF microwave MHz MHz MHz MHz 1 GHz and above Also, consider the following criteria while choosing radios: required communication rate space requirements. Do you need a rack-mounted or stand-alone modem? requirements of the DTE devices to which you are connecting Do you need asynchronous or synchronous operation? Note: If you are using all A-B DTE devices, choose an asynchronous modem interface. What interfaces do you need (RS-232, MIL 188, EIA-449, IEEE 488, CCITT V.24)? What other features are required to support your DTEs? Allen-Bradley Motors

32 3-8 Choosing Data Communication Equipment required diagnostic features Radio modems can either be crystal-based or microprocessorbased. Microprocessor-based modems can be more easily serviced and programmed from a central control site. Diagnostics can be more easily performed on microprocessor-based modems. Technicians do not have to travel to the remote site to diagnose problems; they can perform diagnostics at the control site. power availability at the remote sites required licensing required standards (UL, CSA, FCC, etc.) whether the radio modem is composed of an integrated unit or a radio and a modem as separate units radio modem design and operation needed response time Licensing The FCC requires that you obtain a license before you operate a radio modem at a particular location and frequency within certain radio frequency bands. The advantage of operating within a licensed radio frequency band is that this minimizes the chance of transmission interference from other nearby radio modems. The disadvantage is that in populated areas, most, if not all, of the available radio frequencies are already licensed and in use. FCC allows you to use relatively low transmit power, spread-spectrum radio modems without a license. Spread-spectrum is a transmission-frequency varying technique that lets many spread-spectrum radios operate within the same radio frequency band with some interference. The amount of interference is directly proportional to the number of users in the area.

33 Choosing Data Communication Equipment 3-9 Radio Modem Types Radio modems may be sold as: integrated units Key-up time between the radio and modem is integrated fully. The unit does not require programmable controller intervention. When the modem and transmitter/receiver are separate, compatibility becomes an issue. two separate units: a digital data modem that has an RS-232 connector a radio transmitter/receiver that has an antenna connector Often, since the modem is not able to directly control when the radio transmits a carrier, the data communication device must also have a way to key-up the radio transmitter just prior to transmitting data to the modem. Also, consider the time-to-transmit power requirements of the combination, since the external modem is not able to determine when the radio is at full power. The modem requires a time delay prior to data transmission. Table 3.F describes the type of modem you should choose. Allen-Bradley Motors

34 3-10 Choosing Data Communication Equipment Table 3.F Keep these considerations in mind when choosing radio modems. For this application: Point-to-point, full-duplex Point-to-multipoint (or broadcast), half-duplex Multipoint-tomultipoint, full-duplex Choose this modem type: full-duplex radios This application requires a separate transmitter and receiver in each radio modem. full-duplex or half-duplex master radio, half-duplex remote radios For best performance use a Master radio modem capable of full-duplex operation, since a full-duplex radio modem has a transmitter that is separate from the receiver. This provides shorter RTS-to-CTS delays with each master station data transmission. To be cost efficient, use radio modems for the remote stations that have a transceiver. Having a transceiver limits modems to only half-duplex operation, since they can only send or receive data at one time. Therefore, with each remote station transmission, the RTS-to-CTS delay is longer, since the transceiver takes time to switch from receiver operation to transmitter operation. This time delay lets the transmitter fully power up. Also, think about setting up your master station in a redundant configuration. If the master station's radio modem goes down, the whole communications system is down. Whereas, when a remote station radio modem goes down, only communications to a single remote station is lost. packet radios Although packet radio modems receive and transmit across the airwaves in a half-duplex fashion, they are able to buffer and interpret data received from the attached PLC/SLC that is configured to communicate using DF1 full-duplex protocol. This allows any station to trigger a message instruction in ladder logic and immediately transmit it to the attached radio modem. It is up to its radio, then, to successfully deliver the message packet to the appropriate remote radio modem and its attached station based on the DF1 destination address embedded within the message packet. Like leased-line modems, the cost of radio modems is directly proportional to the communication rate or communications throughput that they can support.

35 Choosing Data Communication Equipment 3-11 See Table 3.G for a listing of recommended radio modem suppliers and respective modem models. Table 3.G Use these recommendations to help you choose radio modems. Consult the vendor for information about their product offerings. Supplier: Transmission Rate: Frequency: Topology: Modem Model: DATA-LINC Group MHz 1 point-to-point point-to-multipoint MHz 1 point-to-point point-to-multipoint MHz 1 point-to-point point-to-multipoint MHz 1 point-to-point point-to-multipoint SRM SRM SRM6200E 3 SRM6200E/FL 2 4 ESTeem MHz multipoint-to-multipoint Model 192V MHz multipoint-to-multipoint Model 192M MHz multipoint-to-multipoint Model 192F MHz multipoint-to-multipoint Model 192C Metricom MHz 1 multipoint-to-multipoint UtiliNet Microwave Data Systems (MDS) 1200, 4800, and MHz point-to-point point-to-multipoint MHz point-to-point point-to-multipoint MHz 1 point-to-point point-to-multipoint 1 Spread-spectrum Radio - NO FCC LICENSE REQUIRED and 1771 rack mount available. 3 Ethernet 10BASE-T interface (no RS-232). 4 Ethernet 10BASE-FL fiber optic interface (no RS-232). Series 2000 Series 4000 Series 9810 Radio Modem Installation Guidelines For a radio system, you need these components: Component: antennas cabinets repeaters (optional) Comments: The height and quality depend upon the application and project budget. Depending on the environmental conditions or the location of the remote sites, select an appropriate cabinet. If the radios are not located in a line of sight with each other (e.g., due to terrain), you may need repeaters that will carry the signal from initiating station to the destination station. Allen-Bradley Motors

36 3-12 Choosing Data Communication Equipment When becoming involved with radio system design, consult radio system vendors. A site survey should always be performed to determine the following: radio transmit power requirements quantity of radios whether or not repeaters are needed antenna type and heights Choose a Satellite Transmission System A Very Small Aperture Terminal (VSAT) network provides a mechanism for multiple remote sites to communicate with a central site (a hub) on a shared access basis. You can choose from two types: Earth System: single-hop double-hop Comments: Data is transmitted across leased lines to the master Earth station, which beams the data to the satellite. The satellite beams the data to the remote sites (or master site). The charges may be high if you purchase your own inbound and outbound channels, and usually, you do not use the channels entire bandwidth. Also, you must pay for the leased line that transports the data to the master hub. You can choose a single-hop system that shares the inbound and outbound channels with others to offset costs. A VSAT site is directly connected to your master or remote station. This VSAT beams the data to the satellite, which beams the data to either the remote site or master site. With a double-hop system, you are not dependent upon the availability of terrestrial leased lines.

37 Choosing Data Communication Equipment 3-13 These components make up a satellite transmission system: power amplifier (transmit)/low noise amplifier (receive) power amplifier (transmit)/low noise amplifier (receive) up/down converter antenna antenna up/down converter satellite modem A Modulator Demodulator A satellite modem remote unit Demodulator B master station up/down converter satellite modem B remote unit If each remote site communicates on a different frequency, then you need a demodulator for each frequency at the master station site Satellite modems are typically supplied by a satellite vendor and bundled with the communication system. For more information about satellite transmission systems, see a local satellite transmission system vendor Choose Power Line Modems You can easily integrate power line modems into your application. You need a power line or other power delivery media and an RS-232 interface. See Table 3.H for a listing of recommended power line modem suppliers and respective modem models. Table 3.H Use these recommendations to help you choose power line modems. Consult the vendor for information about their product offerings. Supplier: Transmission Rate: Topology: Modem Model: DATA-LINC Group maximum of 9600K bps on the power line point-to-point point-to-multipoint LCM100-M LCM100-R For installation requirements, consult the modem vendor. Allen-Bradley Motors

38 3-14 Choosing Data Communication Equipment What To Do Next Choose your data communication equipment. You may need more specific information about control devices to which you are connecting. Therefore, after choosing your master and remote stations, refer to this section as needed to finalize your transmission system. Go to the next section to choose master stations.

39 Chapter 4 Choosing a Device for a Master Station Overview For information about: See page: choosing a VAX- or UNIX-based 4-3 computer choosing a personal-computer-based 4-3 master station choosing a programmable 4-6 controller-based master station choosing a submaster station 4-8 needed equipment 4-10 installation guidelines 4-10 what to do next 4-10 The master station in a SCADA system does the following: gets field data by periodically reading and/or receiving data directly from the remote stations or through a submaster provides coordinated monitoring and control over the entire system through its operator interface Several master station types are possible: VAX-or UNIX-based computer with Interchange Personal computer SLC, PLC or Logix processor RSView32 software with RSLinx 2.0 software Ethernet RS-232 links DH+, Ethernet or ControlNet RS-232 remote stations remote stations Have one or more VAX- or UNIX-based computers communicate with the master station through a local area network connection.use them to initiate control actions to the remote stations via the master station remote stations In small SCADA systems, a single personal computer can serve as both the master station and central computer remote stations Use a programmable controller as a master station if an application requires one or more master station(s) separate from the operator interface, such as when you need to control local inputs and outputs Allen-Bradley Motors

40 4-2 Choosing a Device for a Master Station Very large applications can also require submaster stations, which: gather data from the remote stations within a region support local operator interface for the region support logging of alarms and events communicate remote station data and support control commands interface with a larger, host master station A submaster station controls remote sites within a region. Region 1 communication with master station Operator-interface applications display, log, trend, alarm upon, and report on the data collected by the submaster station operator interface Submaster station collecting data for the region. Components: PLC-5 processor and 1785-KE, or SLC 5/03 processor and 1747-KE, or two Logix5550 processors in a chassis master to remote sites DH+ link remote site A remote site B remote site C 41131

41 Choosing a Device for a Master Station 4-3 Choose a VAX- or UNIXbased Computer Choose a VAX- or UNIX-based computer as a master station when your application has a very large number of remote stations to control. You can also use this type of system to maintain a system database, support a local operator interface, and generate reports and application programs. The application software utilizes Rockwell Software INTERCHANGE Application Programming Interface (API) to communicate over the Ethernet to the master data concentrator. Vax-based or UNIX-based servers supporting single or multiple workstations on a local area network Workstation Workstation VAX or UNIX-based server Requirements: workstations local area network and server operator interface software and/or data collection software programs INTERCHANGE API Ethernet network Choose a Personal Computer-Based Master Station For many small SCADA configurations, a personal computer running Rockwell Software s RSView32 and RSLinx 2.0 software can meet the requirements for both the operator interface and the master station. RSView32 software provides not only an operator interface but also master station functionality, both at the same time. This configuration provides for the most integrated and cost-effective master station for smaller applications. Allen-Bradley Motors

42 4-4 Choosing a Device for a Master Station Use RSView32 software as a master station. Ethernet RSView32 software with RSLinx 2.0 or higher l l l Data sharing RS-232 circuit 4 RS-232 circuit 2 l l l half-duplex protocol Remote Stations half-duplex protocol Remote Stations or full-duplex protocol Station connected via a point-to-point link A total of 300 devices. If only one circuit is used, the system can have 254 devices Each of up to four circuits support either DF1 half-duplex or DF1 full-duplex protocol. Using COM1-COM4 serial ports, you can have RSView32 software connected to four separate telemetry systems. Therefore, an RSView32 master station can be a: master station to four separate SCADA systems when each circuit is configured for DF1 half-duplex protocol half-duplex master on up to three of its circuits and support DF1 full-duplex protocol with dial-up modem support on the other circuit, which is a requirement for some SCADA applications Even when multiple host computers are required, RSView32 Active Display Station option facilitates data sharing between the half-duplex master workstation and other RSView32 workstations over an Ethernet network. A single RSView32-based workstation can simultaneously be: the host computer, running operator-interface software the master station, performing the remote station data-gathering functions the remote station programming terminal To create a cost-effective solution, equip a workstation with the following: RSView32 software RSLinx 2.0 or higher communication server software RSLogix5, 500 or 5000 programming software

43 Choosing a Device for a Master Station 4-5 Use RSView32 software as an operator interface. A personal computer running RSView32 software serves as an operator interface to a PLC-based master station on an Ethernet local area network Ethernet Ethernet Requirements: personal computer with Windows 95 or NT communication card cables RSView32 software RSLinx communication server software (2.0 or higher) For the Logix, PLC or SLC-based master station requirements, see Table 4.A Add RSLogix Frameworks function block programming software to a PLC-5 based master station system and you can configure process control functions and view the control process from one workstation. This software helps to simplify the task of integrating analog I/O modules, PLC-5 programmable controllers, regulatory loops, and operator interface workstations. Allen-Bradley Motors

44 4-6 Choosing a Device for a Master Station Choose a Programmable Controller-based Master Station Choose a programmable controller-based master station if any of these requirements exists: master station must be able to control local I/O application requires master station redundancy Use this chart to help you choose a programmable controller master station. Processor Memory Maximum I/O Points Racks: A-B RS-232 Interface RS-232 Protocol: Maximum Remote Stations 1 : Represented in Kwords unless noted Total Local/Remote 2 DF1 FDX SLC 5/03 8, built-in 1747-KE 1770-KF3 SLC 5/04 SLC 5/05 PLC-5/ / KF2 PLC-5/ / KE PLC-5/20C built-in PLC-5/20E yes yes yes DF1 HDX Master yes no no Modbus yes 3 4 no no 16, 32, built-in yes yes yes 3 4 PLC-5/ /7 PLC-5/40 PLC-5/40C PLC-5/40E /15 PLC-5/40L /15 (15 ext. local) PLC-5/ /23 PLC-5/60C PLC-5/60L /23 (23 ext. local) PLC-5/80 PLC-5/80C PLC-5/80E /23 Logix Kbytes 672 Kbytes 1184 Kbytes 2208 Kbytes 128K discrete 4K analog yes yes yes no no yes 250 1/250 built-in yes yes no 1 This quantity is the total number of nodes allowed on the network; a more efficient network uses fewer nodes. 2 Combination of local, extended local, and remote racks cannot exceed total number of racks available. no no yes Obtain DF1 master and Modbus master station protocols from Miille Applied Research as single-slot modules for the 1746 and 1771 I/O chassis. The maximum number of remote stations for DF1 master is 128; for Modbus, 48. For contact information, see page A-1. 4 Obtain DF1 master and Modbus master station protocols from ProSoft Technologies as single slot modules for the 1746 and 1771 I/O chassis. The maximum number of remote stations for DF1 master is 50; for Modbus, 150. For contact information, see page A

45 Choosing a Device for a Master Station 4-7 Choose the programmable controller based on processor memory requirements. Table 4.A provides a selection guideline for programmable controller-based master stations. The guidelines are based on a maximum of 4K of programming memory for the polling master application logic and 200 words of data table memory per remote station. Other application requirements might dictate specifying a larger processor. Table 4.A Programmable Controller Selection Guide If you have this quantity of remote stations: Choose this processor or larger: 1-10 SLC 5/03 (531) PLC-5/ PLC-5/20 SLC 5/03 (532) SLC 5/04 (541) SLC 5/05 (551) PLC-5/30 SLC 5/04 (542) SLC 5/05 (552) Logix PLC-5/40 SLC 5/04 (543) SLC 5/05 (553) Logix PLC-5/60 5/80 Logix5550 > 254 Multiple Logix5550 If an application requires multiple half-duplex master stations, you can use multiple Logix5550 processors in a single 1756 I/O chassis, with each processor supporting up to 254 remote stations. Using the built-in backplane to serial port routing capability of the Logix5550 processor, any processor has messaging capability to any remote station, no matter which processor serial port it is actually connected to. Allen-Bradley Motors

46 4-8 Choosing a Device for a Master Station Choose a Data Concentrating Submaster Station If your application requires one or more data-concentrating submaster station(s), each submaster station must support both DF1 half-duplex master station and DF1 half-duplex remote station communication through two serial ports. In this application, the submaster can communicate directly with its master or its remote stations, but any data exchange between its master and its remote stations can only occur through the submaster s data table. The master programming terminal can remotely program the submaster, but not the submaster s remote stations. Region 1 communication with master station communication with master station or The PLC-5 or SLC 5/03 processor is configured for master mode. Connected to its serial port is the master modem connection to the remote stations. The 1785-KE or 1747-KE module is the master station s remote link to the submaster station for this region. DH-485 link DH+ link remote site A remote site B remote site C Choose a Data Routing Submaster Station If your application requires one or more data routing submaster station(s), the master station and the submaster station(s) must be Logix5550 processor-based. Each submaster station has two Logix5550 processors, one with its serial port configured for DF1 half-duplex master station communication and the other with its serial port configured for DF1 half-duplex remote station communication.

47 Choosing a Device for a Master Station 4-9 In this application, not only can the submaster communicate directly with its master or remote stations, but the master can initiate messages to the remote stations by routing through the submaster, with no additional programming or data table memory used in the submaster. A programming terminal or MMI computer connected to the master station via Ethernet or ControlNet can also route through the master and submaster in order to program or exchange data with the remote stations. Ethernet or ControlNet Network Logix5550 master station RSView32 RSLogix Logix5550 submaster station MicroLogix remote Logix5550 remote SLC 5/03 remote Allen-Bradley Motors

48 4-10 Choosing a Device for a Master Station Needed Equipment Installation Guidelines What To Do Next Allen-Bradley offers a wide variety of chassis, power supplies, and I/O modules to help you automate your application. See the Automation Systems Catalog for more information. You must provide an appropriate environment and proper grounding for programmable controller systems. See the Programmable Controller Wiring and Grounding Guidelines, publication , for more information. You should: Choose your master and submaster stations and operator interfaces according to your application requirements. Record these choices on the checklist (page 1-9). Finalize any telemetry equipment decisions. Consult the Automation Systems Catalog to begin designing any needed control systems. Go to the next section to choose your remote stations.

49 Chapter 5 Choosing a Device for a Remote Station Overview For information about: See page: choosing a device 5-2 needed equipment 5-7 installation guidelines 5-7 what to do next 5-7 A remote station in a SCADA application does the following: controls inputs and outputs of field devices, such as valves, metering equipment, and drives monitors conditions of the field devices and logs alarms reports status to the master station and carries-out the commands it receives from the master station Master Station Remote PLC-5 Station Pump Station Remote SLC 5/03 Station Gas Metering Station Remote Logix5550 Station Pump Station Remote MicroLogix 1000 Station Waste-water Treatment Plant Allen-Bradley Motors

50 5-2 Choosing a Device for a Remote Station Choose a Device Choose from a variety of remote stations that fit your application and cost requirements. The most cost-effective remote station for applications that use limited analog and/or discrete I/O is the MicroLogix 1000 programmable controller. Otherwise, choose a SLC 500 system for your remote station unless specific redundancy, I/O, or communication requirements are only met by a Logix5550 or PLC-5-based solution. MicroLogix 1000 or SLC 5/0(x) Processor-based Remote Stations Use this table to help you choose a MicroLogix 1000 or SLC programmable controller for your remote station(s). If your application meets any of the following: Choose: Requirements: uses no analog I/O discrete I/O requirement falls within either: 6 in/4 out, 10 in/6 out or 20 in/12 out analog I/O requirements fall within: 2 single-ended +/ VDC inputs 2 single-ended +/- 21 ma inputs 1 single-ended 0-10 VDC or 4-20 ma output discrete I/O requirement falls within: 12 in/8 out integrated dial-out phone modem control using ASCII instructions 8K, 16K, 32K, or 64K program/data table memory floating point math and PID capability online programming capability key switch built-in clock/calendar separate local MMI/programming communication port 48 VDC and 125 VDC power supply options requires a protocol other than DF1 no need for remote station programming over the telemetry system MicroLogix 1000 Programmable Controller MicroLogix 1000 Programmable Controller with Analog SLC 5/03, SLC 5/04 and SLC 5/05 Modular Controller third party module with a SLC 5/0(x) processor Built-in serial port. (Recommend using AIC+ to optically isolate serial port) Built-in serial port. (Recommend using AIC+ to optically isolate serial port) SLC 5/03, SLC 5/04 and SLC 5/05 processors have a built-in serial port as well as either a DH485, DH+ or Ethernet ports See page 2-9 for protocol modules available from ProSoft Technology, Inc., Miille Applied Research Co., Inc., and Real Time Automation.

51 Choosing a Device for a Remote Station 5-3 Processor Memory (Kwords) Maximum Local I/O Points # Local Chassis: A-B RS-232 Interface RS-232 Protocol: MicroLogix discrete in/ 4 discrete out 10 discrete in/ 6 discrete out 20 discrete in/ 12 discrete out MicroLogix 1000 with Analog 1 12 discrete in/ 8 discrete out 4 analog in/ 1 analog out SLC 5/03 8, built-in 1747-KE 1770-KF3 SLC 5/04 SLC 5/05 DF1 FDX DF1 HDX Slave 1 built-in yes yes yes 2 1 built-in yes yes yes 2 yes yes yes yes yes yes Modbus Slave yes no no 16, 32, built-in yes yes yes Obtain Modbus remote station protocol from ProSoft Technology, Inc. as single-slot modules for the 1746 I/O chassis 2 Obtain Modbus remote station protocols from Miille Applied Research Co. (MARC) as single-slot modules for the 1746 I/O chassis. MARC has also developed a stand alone, DIN-rail mount interface that converts DF1-full duplex to Modbus, and can be used to interface MicroLogix on Modbus. Contact MARC for details. 3 An equivalent SLC 5/03 processor with built-in Modbus is available from ProSoft Technology, Inc., as the RTU 5/03. Allen-Bradley Motors

52 5-4 Choosing a Device for a Remote Station PLC-5 Processor-based Remote Stations Choose a PLC-5 processor if your application also requires: a redundant PLC processor system specific I/O requirements only met by 1771-based I/O Generally a PLC-5/11 processor fits most PLC-5 processor-based, remote-station solutions. However, choose a PLC-5/20, -5/30, -5/40, -5/60, or -5/80 processor based strictly on memory size or I/O quantity requirements of your application. Enhanced PLC-5 processors provide a cost-effective solution because you do not need to purchase a separate serial interface. Use a 1785-KE module as shown below, if your application requires multiple PLC-5 processors located at a single remote site. The 1785-KE module is operating in remote slave mode. The master station can directly solicit data from any PLC-5 system at the remote site via the DH+ link. communication with master station Remote Site operator interface DH+ link connected to 1785-KE DH+ link 41138

53 Choosing a Device for a Remote Station 5-5 Use this table to help you choose a PLC-5 processor for a remote station. Processor Memory (Kwords) Maximum I/O Points Racks: A-B RS-232 Interface RS-232 Protocol: Total Local/Remote DF1 FDX PLC-5/ /1 built-in PLC-5/20 PLC-5/20C PLC-5/20E /3 PLC-5/ /7 PLC-5/40 PLC-5/40C PLC-5/40E /15 PLC-5/40L /15 (15 ext. local) PLC-5/ /23 PLC-5/60C PLC-5/60L /23 (23 ext. local) PLC-5/80 PLC-5/80C PLC-5/80E / KE 1770-KF2 1 Obtain Modbus remote station protocol from ProSoft Technology, Inc. as a single-slot module for the 1771 I/O chassis. yes yes yes yes yes yes DF1 HDX Slave 2 Obtain Modbus remote station protocol from Miille Applied Research Co. Inc. (MARC) as a single-slot module for the 1771 I/O chassis. yes 1 2 no no Modbus Slave Logix5550 Processor-based Remote Stations Choose a Logix5550 processor if your application also requires: bridging to/from other devices connected at the remote station on Ethernet or ControlNet networks in conjunction with a Logix5550 master station specific I/O requirements only met by 1756-based I/O Allen-Bradley Motors

54 5-6 Choosing a Device for a Remote Station See the figure below if your application requires multiple Logix5550 processors located at a single remote site. The Logix5550 processor connected to the modem is configured to communicate using DF1 half-duplex slave protocol. The master station Logix5550 processor can directly solicit data from any Logix5550 system at the remote site via Ethernet or ControlNet. operator interface communication with Logix5550 master station remote site Ethernet or ControlNet Network Needed Equipment Installation Guidelines What To Do Next Allen-Bradley offers a wide variety of chassis, power supplies, and I/O modules to help you automate your application. See the Automation Systems Catalog for more information. You must provide an appropriate environment and proper grounding for programmable controller systems. See the Programmable Controller Wiring and Grounding Guidelines, publication , for more information. You should: Choose a remote station for each remote site in your application. Finalize any telemetry requirements. Record these choices on the worksheet (page 1-9). Finalize any telemetry equipment decisions. Consult the Automation Systems Catalog to begin designing any needed control systems.

55 Appendix A Third-Party Supplier Contact Information Introduction This Section lists contact names for the third-party products mentioned in this document. For more information about either the vendors or products, do any of the following: contact the vendor directly see the Encompass Product Directory, publication 6873 contact your local Allen-Bradley office or distributor Contact List Please use this as a reference. This list is not inclusive. Black Box Corp. DATA-LINC Group Company: Product types offered: Contact information: dial-up and leased line modems, line drivers dial-up, leased-line, spread spectrum radio, and power line modems Black Box Corp. Customer Service P.O. Box Pittsburgh, PA Phone: (412) Fax: (800 or 412) DATA-LINC Group st Place., NE Redmond, WA Phone: (425) Fax: (425) Electronic Systems Technology ESTeem radio modems Electronic Systems Technology 415 N. Quay Street Kennewick, WA Phone: (509) Fax: (509) Metricom, Inc. spread spectrum radio modems Metricom, Inc. 980 University Ave. Los Gatos, CA Phone: (800) (408) Fax: (408) Microwave Data Systems radio modems Sales Coordinator Microwave Data Systems 175 Science Parkway Rochester, NY Sales and Engineering Phone: (716) General Phone: (716) Fax: (716) Allen-Bradley Motors

56 A-2 Company: Product types offered: Contact information: Miille Applied Research Co., Inc. (MARC) ProSoft Technology, Inc. Real Time Automation protocol converters, 1771 and 1746 chassis mounted modems for dial-up and leased line protocol interfaces for SCADA, plant floor and foreign device interface applications. custom development and tools are also available the ProSoft RTU-5/03 Processor is targeted at SCADA/RTU applications in industries that use the Modbus protocol protocol interfaces for SCADA, plant floor and foreign device interface applications. custom development and tools are also available Miille Applied Research Co., Inc S. Richey Pasadena, TX Phone: (713) or Fax: (713) ProSoft Technology, Inc. Corporate Office 9801 Camino Media Suite 105 Bakersfield, CA Phone: (805) Fax: (805) Real Time Automation 2825 N. Mayfair Road Wauwatosa, WI Phone: (414) Fax: (414)

57 Glossary ACK Acknowledgment Asynchronous transmission BCC Bridge Classic PLC-5 Processor CRC CTS ControlLogix I/O ControlLogix System DCD See Acknowledgment. An ASCII control character that indicates the transmission and acceptance of data. A method of serial transmission where characters may be transmitted at unequal time intervals. Asynchronous transmission requires that each character contains start/stop elements so the receiver can detect the start and end of each character. Block-Check Character. The 2 s complement of the 8-bit sum (modulo-256 arithmetic sum) of all data bytes in a transmission block. It provides a means of checking the accuracy of each message transmission. An interface between links in a communication network that routes messages from one link to another when a station on one link addresses a message to a station on another link. A collective name used to refer to PLC-5/10, -5/12, -5/15, and -5/25 processors. Cyclic redundancy check. An error detection scheme where all of the characters in a message are treated as a string of bits representing a binary number. This number is divided by a predetermined binary number (a polynomial) and the remainder is appended to the message as a CRC character. A similar operation occurs at the receiving end to prove transmission integrity. Clear-To-Send. A signal from the DCE that tells the transmitting device (DTE) to start transmitting data. The integral I/O platform for the ControlLogix Series of programmable controllers providing the system with the latest I/O technology supporting customers control and information needs Applies the new producer/consumer networking model to the I/O architecture. This means that the I/O modules produce information (both state and diagnostic data) when needed, eliminating the need for processors to continually poll I/O. Data Carrier Detect; a signal indicating that the carrier is being received from a remote DCE. Allen-Bradley Motors

58 G-2 Glossary DCE DF1 Digital Data Service (DDS) DSR DTE DTR Data Communication Equipment 1) Equipment that provides the functions required to establish, maintain, or terminate a connection. 2) The signal conversion and coding required for communication between data terminal equipment and data circuits. Examples include modems, line drivers, coaxial cable, satellite links, etc. DCE may or may not be an integral part of a computer. The Allen-Bradley asynchronous protocol. A special wide-bandwidth Private Leased Line (PLL) that uses digital techniques to transfer data at higher speeds and lower error rate than voice-band, analog PLLs. The line is available 24 hours a day. Data-Set-Ready. A signal that indicates the modem is connected, powered up, and ready for data transmission. Data Terminal Equipment. Equipment that is attached to a network to send or receive data, or both. Programmable controllers, workstations, and interface modules are examples of DTEs. Data-Terminal-Ready. A signal that indicates the transmission device (terminal) is connected, powered up, and ready to transmit. Enhanced PLC-5 Processors A collective name used to refer to PLC-5/11, -5/20, -5/30, -5/40, -5/60, and PLC-5/80 processors. EOT Ethernet PLC-5 Processors Extended Local PLC-5 Processors FCC Full-Duplex Circuit Full-Duplex Modem Full-Duplex Protocol End Of Transmission; an ASCII control character that indicates the end of a data transmission. A collective name used to refer to PLC-5/20E, -5/40E, and -5/80E processors. A collective name used to refer to PLC-5/40L and -5/60L processors. Federal Communication Commission (United States). A physical circuit that allows simultaneous, bidirectional transmission of data; also called a "four-wire" circuit. A modem that is capable of simultaneous, bidirectional transmissions. 1) A mode of operation for a point-to-point link with two physical circuits, in which messages or transmission blocks can be sent in both directions at the same time. 2) Contrasted with two-way alternate.

59 Glossary G-3 General Switched Telephone Network Half-Duplex Circuit Half-Duplex Modem Half-Duplex Protocol Handshake Integrated Service Unit (ISU) I/O Rack Link Logix5550 Master Station International version of a Public Switched Telephone Network. A physical circuit that allows transmission of data in either direction but not at the same time. A modem that sends and receives messages on carriers of the same frequency. Therefore, simultaneous, bidirectional transmissions are not possible. 1) A mode of operation for a point-to-point or multipoint baseband link with two physical circuits, in which messages or transmission blocks can be sent in one direction or the other but not both at the same time. 2) Contrasted with two-way simultaneous. The master station-to-remote station communication uses a half-duplex protocol. A series of signals between a computer (DTE) and a peripheral device (DCE; e.g., a modem) that establishes the parameters required for passing data. Data communication equipment for a digital data network, which serves as the data transmitting and receiving device. An ISU is a combination of a digital service unit (DSU) and a channel service unit (CSU). An I/O addressing unit that corresponds to 8 input image table words and 8 output image table words. A data channel established between two or more stations. As part of the ControlLogix System, the Logix5550 Controller is a high functionality device capable of addressing the same requirements as the mid-sized PLC-5 controllers, but with significant functionality for addressing more complex sequential and process applications. Key benefits include multi-processors within a chassis, multitasking, interrupt driven controllers, highly integrated motion control, use of RSLogix 5000 Software, WinNT/95 support, improved performance, symbolic addressing and controller local/global data scoping A device (programmable controller with I/O modules or a workstation) that sends data to and collects data from devices connected on a point-to-multipoint, half-duplex network. Allen-Bradley Motors

60 G-4 Glossary Modem Modem Handshaking Multidrop Link NAK Node Octal Numbering System Packet Packet Radio Modem PAD Parallel port Point-to-multipoint Point-to-point Poll A device that modulates digital information from a programmable controller or computer to an analog signal that is transported over phone lines, radio waves, and satellite transmissions and demodulates the analog data back into digital data at the receiving site. A signaling protocol used for transferring information between devices in a synchronized manner at a rate acceptable to both devices. It may be accomplished by hardware or software. 1) A link that has more than 2 stations. 2) Contrasted with point-to-point link. Negative Acknowledgment. An ASCII control character transmitted by a receiver as a negative response to the sender. A station on a network. A numbering system that uses only the digits 0-7; also called base-8. The transmission unit exchanged at the network layer. An intelligent radio modem that organizes the data it receives from the transmitting station into packets. The modem places a header and a trailer around the data before it transmits the data to the destination device. The header can also contain routing information. Packet radio modems also perform their own data error checking and will re-transmit the data if an error is encountered. Packet assembler/disassembler. Equipment used to assemble and disassemble data packets for transmission on a packet-switching network such as a satellite system. An electrical connection on a computer capable of transmitting or receiving two or more bits of data at one time; the communications port to which such devices as parallel printers can be attached. A network where connections exist between one master station and multiple remote stations. A network where a connection is made between two and only two terminal installations. When the master station sends a message to a remote station that allows the remote station an opportunity to return a response to the master or another remote station. In this manual, when the master polls a remote station, it is not initiating a read request.

61 Glossary G-5 Polling cycle Poll List Protocol Private Leased Line Network (PLL) Public Switched Telephone Network (PSTN) RS-232 RTS RTU RXD Remote Station SCADA Slave Slave Protocol Serial Port Spurious Character The order and frequency in which network nodes in a poll list are polled. A list of nodes or stations on a network to be polled on a regular and repeated basis. A set of conventions governing the format and timing of data transmission between communication devices, including handshaking, error detection, and error recovery. A dedicated voice-band telephone line between two or more locations primarily used for data transmission. The standard dial-up telephone network originally used for voice communication. An EIA electrical connection standard, most often used as a standard interface for serial binary communication between data terminal equipment and data communications equipment. Request To Send. A request from the DTE module to the modem to prepare to transmit. In response, the modem typically sends out a data carrier signal and turns on CTS. Remote Terminal Unit. See remote station. Received Data; a serialized data input to a receiving device. A device (programmable controller with I/O modules) that is located in a remote site away from the master station and that controls I/O points at the remote site. A remote station accepts commands from and can send data (if capable) to a master station via a telemetry network. Supervisory Control and Data Acquisition See remote station. See Half-Duplex Protocol. An electrical connection on a computer that handles data bits one after another; the communications port (COM1 or COM2) to which devices such as a modem, a mouse, or a serial printer can be attached. A false or unexpected character received when none is expected. Allen-Bradley Motors

62 G-6 Glossary Standard Radio Modem Station Station Addressing Synchronous Transmission Telemetry Topology Transceiver TXD A standard radio modem is an assembly that contains both a radio and a modem, which transmits data without any special handling. Data error checking is the responsibility of the receiving station (DTE). Any programmable controller, computer, or data terminal connected to, and communicating by means of, a data channel; a device on a network. The syntax allowing packets to be routed correctly between master and remote stations. A type of serial transmission that maintains a constant time interval between successive events. Transmission and collection of data obtained by sensing real-time conditions. The way a network is physically structured. Example: a ring, bus, or star configuration. An electronic device that operates as both a radio transmitter and receiver. Transmitted Data; an output from the module that carries serialized data. The following are registered trademarks of Rockwell Automation: PLC PLC-2 PLC-3 PLC-5 The following are trademarks of Rockwell Automation: PLC-5/11 PLC-5/12 PLC-5/15 PLC-5/20 PLC-5/20C PLC-5/20E PLC-5/25 PLC-5/30 PLC-5/40 PLC-5/40C PLC-5/40E PLC-5/40L PLC-5/60 PLC-5/60C PLC-5/60L PLC-5/80 PLC-5/80C PLC-5/80E PLC-5/250 SLC SLC 500 SLC 5/01 SLC 5/02 SLC 5/03 SLC 5/04 SLC 5/05 Ethernet PLC-5 Ethernet Gateway Enhanced PLC-5 Classic PLC-5 Extended Local PLC-5 ControlLogix ControlView ControlView 300 DH+ Logix5550 Resource Manager Pyramid Integrator VAX and MicroVAX are registered trademarks of Digital Equipment Corp. Com-Troller, Com-Master, and Omnii-Com are trademarks of Miille Applied Research, Inc.. Modbus is a trademark of Modicon.

63 Allen-Bradley Motors PN Supersedes Publication AG June Rockwell International. All Rights Reserved. Printed in USA