Contents. Introduction / Description of operation. Alphabetical index of products Introduction Brief system description

Transcription

1 K21-01 Introduction

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3 K Introduction / Description of operation 1/1 Contents Alphabetical index of products Introduction Brief system description Principle of operation of the RS controller RS controller block diagram Handling of process variables Description of the operating system Communication / RS bus

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5 K K21 alphabetical product index 1/2 Type code Item Data sheet/page NABBS/A RS bus adapter with power supplyk NARB/A RS bus adapter K NARC RS bus adapter with interface converter K NARS Supply voltage adapter K NATU Adapter for special signals K NBE Remote operator terminal K /5, K NBRN-.. Hand-held operator terminal K /5, K NBRNA-.. Hand-held operator terminal K /5, K NHGB Card-frame K NICO MS2000 interface K NIPRO pronto interface K NITEL.. Communications module K NIWEB Communications module K NKDG Transducer module for DC V signals (DC 15 V) K NKDW Transducer module for DC V signals (AC 24 V) K NKIA Input module for DC V signals (AC 24 V) K NKIAI Input module for 0 (4) ma signals, with electrical isolation K NKIAU Input module for DC V signals, with electrical isolation K NKIAV.. Input modules for Pt100 sensors K NKIAVN Input module for Landis & Staefa Ni1000 sensors K NKIC Input module for pulse counting K NKID Input module for digital signals K NKIDH as NKID, but with manual switch K NKIDP Input module for digital signals from volt-free contacts K NKIDP/8 Input module for 8 digital signals from volt-free contacts K NKIDPH as NKIDP, but with manual switch K NKIT Input module with trimmer for T1 sensors K NKOAI Output module for 0 (4) ma signals, with electrical isolation K NKOAS Output module for DC V signals K NKOASA as NKOAS, but without hard-wired interlock K NKOASH as NKOAS, but with manual switch K NKOAU Output module for DC V signals, with electrical isolation K NKOD Output relay module K NKODH as NKOD, but with manual switch K NKOK Output module for 3-point signals K NKOKFH Output module for 3-point signals, with manual switch K NMID Multiplexer, 4/1 K NMIDK Multiplexer, 56/8 K NRD24/A RS controller K NRK9/A RS controller K NRK14-T../A RS controller with built-in communications module K NRK16-B/A RS controller with operator panel K NRK16-B1/A RS controller with operator panel K NRK16-T../A RS controller with built-in communications module K NRK16/A RS controller K NRK16-Web Compact Controller with Web Operation K NRUA/A RS controller K NRUB/A RS controller K NRUC/A RS controller K NRUD/A RS controller K NRUE/A RS controller K NRUF/A RS controller K

6 K K21 alphabetical product index 2/2 NRUT../A RS controller with built-in communications module K NSA Application module K NTIM Input terminal module carrier K NTIO Single terminal module carrier K NTIOS Carrier for two terminal modules K NTOM Output terminal module carrier K NTOMS Output terminal module carrier with power supplyk INTEGRAL RSA RS application controllers (NRK../A) K /4, K INTEGRAL RSC RS compact controllers (NRUE/A, NRUF/A, NRUT/A, NRD24/A) K /4, K INTEGRAL RSM RS card module controllers (NRUA/A... NRUD/A) K /3, K Z237 Service cable: NBRN RS controller K /1 Z257 / 259 Cables connecting PC RS controller via RS232 K /2 Z T1 sensor simulators K /3 Z276 Simulator for active sensors K /4 Z277 / 278 Voltmeters K /5 Z332 T1 signal adjuster unit K /6 Z347 Adapter for GND conductor: NTIM RS controller K /7 Z392 Adhesive labels for NSA K /8 Z398 Adhesive labels for NRK16-B/A K /8 Z399 Connecting cable for two or more NRK../A controllers K /9 Z400 Wall-mounting kit for NBRN.. K /9 Z402 NRK16-B/A front-mounting kit K /10 Z404 NBE mounting clip K /11 Z405 Adhesive labels for NBE K /11 Z406 NBRN.. NBE adapter K /11

7 K Introduction 1/8 Brief system description Application INTEGRAL AS1000 is both as a stand-alone control and interlock system for small heating, ventilation and air conditioning systems, and provides the process control level for the following Staefa management systems: INTEGRAL MS2000 building management system INTEGRAL TS1500 remote buildings management system INTEGRAL MS1000 in-house management system The PRONTO IRC individual room control system can be incorporated via an interfa ce into the AS1000 system System overview MS1000 TS1500 MS RC1500 C RC1500 A/B (MC1500) Vision Access Management level NCRS NCRS System coordination and communication AS1000 NITEL NITEL NICO-N Local operation INTEGRAL DIALOG, INTEGRAL RS-SERViCE NBE NBRN.. THERMO RH500 NITEL INTEGRAL RS control and interlock RSM RSC RSA NIPRO PRONTO IRC individual room control ZS1

8 K Introduction 2/8 System configuration Overview see pages 6 and 7. At the heart of the INTEGRAL AS1000 control and interlock system are the microprocessor-based RS controllers. These are available in the following categories: INTEGRAL RSM Programmable control and interlock devices in card-module format, with an external interface for connection to the peripheral devices (see page 3). INTEGRAL RSC Programmable control and interlock devices in compact format with built-in interfaces for connection to the peripheral devices (see page 4). INTEGRAL RSA Application controllers with pre-programmed plug-in modules for system-specific applications, and with built-in interfaces for connection to the peripheral devices (see page 4). The application programs are written using the engineering tool INTEGRAL PLAN or INTEGRAL PLAN+. For simple structuring and parameter setting (see page 8) the Staefa programming language SAPIM (Structure and Parameter Identification Menu) is also available. The interface modules used to connect a PC operator station or higher-level management system, or to incorporate the individual room control system, have the same hardware construction as the RSM card modules. Configuration notes NICO When the NICO interface is used for connection to an MS2000 system, the maximum number of RS modules is normally restricted to 15 per bus. The NICO interface is available in the form of NRK16-C/A device also. NITEL The NITEL interfaces are available in the form of NITEL.., NRK14-T../A, NRK16-T../A, NRUT../A devices. The NITEL can communicate with all 16 modules on a bus. PRONTO IRC individual room control system The PRONTO IRC individual room control system can be integrated into the INTEGRAL AS1000 system by use of the NIPRO interface. This not only integrates the control and interlock functions but also permits centralised operation of the individual room controllers. See the P.. series of documents for a detailed description of the individual room control system. RS bus The RS modules, interfaces and operator terminals are interconnected by a data cable referred to as the RS bus. When a number of RS card modules are slotted together, an internal RS bus connection is created through the interlocking module bases. The external RS bus cable for connection to remote RS bus users can be up to 2400 m in length. For longer distances, short-haul modems or adapters for the connection of fibre optic interfaces are available. Up to 16 RS modules and pronto interfaces, and up to 16 operator terminals (NBE, NBRN..) or communication interfaces (NITEL.., NICO) may be connected to one RS bus.

9 K Introduction 3/8 INTEGRAL RSM The RSM range comprises four RS card modules with different configurations of inputs and outputs (see K , page 1). The signals between the controllers and peripheral devices (sensors, controlled devices, starters etc.) are adapted and transferred externally via the terminal modules and terminal module carriers. The external interface has a number of advantages: The low voltage of the peripheral devices is separated from the extra low voltage of the system The manual/automatic change-over switches for service and commissioning purposes are located directly on the terminal modules The power amplification of the analogue outputs (phase cut signals) does not place any additional load on the RS modules Signal output status is indicated by LED The I/O configuration can be modified as required to match a wide range of peripheral devices RS card modules NRUA/A NRUB/A NRUC/A NRUD/A Terminal module carrier with terminal modules NT.. with NK.. See K21-02 for RSM specifications

10 K Introduction 4/8 INTEGRAL RSC The RSC controllers are particularly suitable for "off-the-shelf" solutions (e.g. air conditioning units for laboratories or computer rooms, etc.). The RSC range comprises three RS compact controllers with different input/ output configurations (see K and K ). The NRUT../A communications controller, an RS compact controller with a built-in NITEL.. communications module for the INTEGRAL MS1000 and INTEGRAL TS1500 systems is described in technical manual NT21. The peripheral devices (sensors, controlled devices, starters, etc.) can be connected directly to the screw terminals on the compact controllers. RS compact devices NRD24/A NRUE/A See K21-03 for RSC specifications. NRUF/A NSA application modules The plug-in modules are held in applications libraries in the various national and regional Landis & Staefa offices. They can be selected to suit the application required and plugged into one of the base units. The engineering required is thus minimal, and since most setpoints, parameters etc. have suitable default settings, commissioning is very easy. Also available freely programmable INTEGRAL RSA The RSA range is primarily used in smaller HVAC systems. RSA comprises three application controllers (see K and 04.20) and a large number of plug-in application modules. Each of these modules contains an EEPROM loaded with an applicationspecific program. The NRK16-T../A and NRK14-T../A communications controllers (RS applications controllers with a built-in NITEL.. communications module) for the INTEGRAL MS1000 and INTEGRAL TS1500 systems is described in the technical manual, document NT21. The peripheral devices (sensors, controlled devices, starters etc..) can be connected directly to the connection terminals on the controller base units. RS application controllers NRK9/A NRK16/A See K21-04 for RSA specifications. NRK16-B/A NRK16-B1/A

11 K Introduction 5/8 Options for local operation via RS bus NBE remote operator terminal The NBE remote operator terminal is designed for simple operation of the HVAC system with INTEGRAL AS1000. The NBE is connected to the RS bus and can be operated without any specific training in HVAC engineering. See K for NBE specification NBRN.. operator terminals The NBRNA-.. allows access to all the RS controllers from anywhere in the system and provides data needed for operation. The NBRN-.. operator terminal can be used for more sophisticated operation. The terminal is designed to provide access to all connected data points based on pre-definable access criteria (e.g. in accordance the technical expertise of the user). NBE NBRNA-.. NBRN-.. Technical specifications, see K (NBRNA-..) and K (NBRN-..). PC operation with the INTEGRAL DIALOG or INTEGRAL RS-SERVICE software The system can also be operated from a PC running the INTEGRAL DIALOG or INTEGRAL RS-SERVICE software. A NITEL.. communications module is required for INTEGRAL DIALOG, and an NARC adapter for INTEGRAL RS-SERVICE. System operation emulates operation with the NBRN-.. operator terminal. See K or K for a brief description of operation with INTE- GRAL DIALOG See K for the NARC adapter technical specification See K for the NITEL.. technical specification (NIBB emulation) INTEGRAL DIALOG software operating instructions - see User manual K8 or K9 INTEGRAL RS-SERVICE operating instructions - see User manual M5 Options for centralised operation Where INTEGRAL AS1000 forms part of an overall management system, the system is operated from the associated management station. The options for local operation continue to be available.

12 Alar Aut INTEGRAL AS1000 K Introduction 6/8 Overview of the INTEGRAL AS1000 control and interlock system INTEGRAL DIALOG or INTEGRAL RS-SERVICE NARC NBE AC 24 V NBRN(A)-.. NARB/A NARB/A NRUA/A NRUD/A NITEL NTOMS NTOMS AC 24 V NTIM NTIM NTOM NTIM NTOM AC 24 V NTIM

13 K Introduction 7/8 NABBS/A NBRN-.. AC 24 V RS bus NARB/A NARB/A NARB/A NRK16/A NIPRO AC 24 V NRUE/A AC 24 V AC 24 V NAPC AC 24 V 2 pronto trunks

14 K Introduction 8/8 Note SAPIM (Structure and Parameter Identification Menu) is a programming language developed by Staefa Control System for the programming of control and interlock modules. It consists of a wide range of basic functions (software modules) which can be combined to create all the structures required. Engineering and commissioning The design engineering, instrumentation, programming and commissioning of the AS1000 system involves various activities which can be defined collectively as "engineering". The starting point for all the engineering activities is the plant diagram, used in conjunction with the description of functions. The basic functions can be compiled on the basis of these documents, and logically connected by combining SAPIM software components to produce a system-specific structure. See K21-08 for a brief description of the SAPIM basic functions. For a detailed description, see the engineering manual M3. Structure diagram The structure diagram is a schematic diagram showing which SAPIM basic functions are needed to operate the system, and the way in which they are logically interconnected. Each function may be used as many times as necessary. F F 9H475 A F F F F Logically interconnected SAPIM software components For more complex systems, the structure diagram can be divided into operating modes (Day, Night, Frost etc.). This approach not only makes the structure diagram easier to read, but also improves operation by reducing the sampling rate, since the microprocessor only needs to sample and process the functions in the active operating mode. Application program On the basis of the system documentation and the structure diagram, the application program can now be created on a PC. To do this, the user invokes the functions shown in the structure diagram one after the other (by use of the relevant codes F1, F2 etc.) and allocates the relevant inputs, outputs and parameters. The process is interactive: after choosing a SAPIM basic function, the user is prompted systematically for all the associated inputs, outputs and parameters. All the requested inputs must be made before the user can complete a function and invoke the next. Engineering with INTEGRAL PLAN The INTEGRAL PLAN software is a convenient tool for the efficient engineering of the INTEGRAL AS1000 control and interlock system. It is based on SAPIM programming language and runs on IBM-compatible PCs or laptops. staefa plan short can be used to structure all the functions of the various RS controllers and to set the associated parameters. A clear graphics-based method of operation combined with intelligent user guidance reduces engineering time and minimises the possibility of programming errors. See User Manual M3 for a detailed description of the engineering software. Downloading the structures In the commissioning phase, the completed application programs are downloaded directly from a PC or laptop computer into the RS controllers and pronto interfaces. Normally it is then only necessary to adjust individual parameters on the basis of the system performance. Further structures can be added and parameters changed at any subsequent stage. See K21-12 for information on commissioning.

15 K /3 Principle of operation of the RS controller Aim of this description The RS controllers are freely programmable DDC-based control and interlock modules. Plant functions once implemented by combining a number of devices are now stored in program form, between the inputs and outputs of the RS controller. The purpose of this description is to provide a somewhat simplified, but nevertheless realistic picture of the structure of, and interaction between the hardware and software in the RS controllers. Input/output section: Comprises the input interface (IN) and the output interface (OUT), each with its associated multiplexer and demultiplexer (MUX) and the auxiliary processor with A/D and D/A converter. Processing section: Consists of the main processor with its RAM and associated buffers: the intermodule buffer (IMB), the input buffer and the output buffer. These buffers are actually components of the RAM, but are shown separately because of their special functions. EPROM: This accommodates the operating system software comprising the operating system (top) and the library of all the SAPIM functions (bottom). EEPROM: This accommodates the project-specific program in SAPIM (top) and the related lists of parameters and text labels (bottom). The project-specific program is divided into the various operating modes of the plant (in this case Night, Frost protection and Day) and Operating mode 0. Operating mode 0 contains the parameters in accordance with which the processor selects the plant operating mode valid at the time. Bus system: This enables all the functional units to communicate with each other, and is also connected with the "outside world" (RS bus, operator terminal) via the BUS interface. Real-time clock (RTC): Shows the current day, date and time. RS controller structure The diagram below illustrates the structure of an RS controller. The example used is the NRUA/A controller, with eight universal inputs and eight universal outputs. Every RS controller consists essentially of the following functional elements: Input/output section Processing section Memory for the operating system software (EPROM) Memory for the project-specific program (EEPROM) Bus system Real-time clock X t 1 UI t 8 IN MUX A INPUT BUFFER IMB RAM MAIN PROCESSOR x Ø x y W x p W x p P EEPROM y D AUXILIARY PROCESSOR BUS D A OUT MUX 60002en UO 1 OUTPUT BUFFER BUS INTERFACE RTC P PI 8 y = f(x, w, Xp,) y = f(x, w, Xp,) EPROM y

16 K /3 Processing the project-specific program Multiplexer: Transfers information from various data channels to a single path. All channels are interrogated in sequence. Demultiplexer: Reverses the process. Distributes the data from a single path to various data channels. X t 1 UI t IN MUX 8 A D 1 6 AUXILIARY PROCESSOR D A 60003en UO 1 OUT MUX 8 y A/D converter: Circuit which converts analogue values into digital code. INPUT BUFFER OUTPUT BUFFER D/A converter: Circuit which converts digital code into analogue values. B 4 IMB RAM 5 A BUS INTERFACE Buffer: Memory in which data is stored temporarily (on call). Interface: Point at which two interacting devices or systems are connected. The signal levels and the routine are coordinated/standardised to enable the devices to communicate. 2 MAIN PROCESSOR Ø BUS RTC Processor: Functional unit within a digital computer system. The processor controls the routine and executes the processing commands. RAM: Random Access Memory. Allows data to be accessed within fractions of a second, modified and stored again. The data is lost, however, if the power supply is interrupted. x x y W x p W x p P y 3 P PI y = f(x, w, Xp,) y = f(x, w, Xp,) EPROM: Erasable, programmable read-only memory. The data is programmed into the memory during manufacture and is retained even if the power supply is interrupted. The complete contents can be erased by ultra-violet light. EEPROM: This has the same properties as the EPROM except that the data can be deleted electrically and reprogrammed by the processor itself. EEPROM EPROM Preparation Step A: The structuring device is used to download the project-specific control and interlock program from the data disk into the EEPROM of the RS controller via the RS bus/service socket. Step B: The RS controller operating system copies the list of parameters for the project-specific program into the intermodule buffer.

17 K /3 Execution Step 1: The operating system causes the current reading or status of the inputs to be scanned every 100 ms. These values are stored in the input buffer. Analogue values are first converted by the A/D converter of the auxiliary processor into digital codes. The same applies to the control variable, x, at input UI 1. Step 2: The current operating mode of the plant is now determined on the basis of the data in Operating mode 0. Assuming that the plant switch in the example is set to "Automatic", that the clock indicates "Day" and that there is no danger of frost, then the main processor will process the program for the "Day" operating mode, working through each function of this SAPIM structure in turn. The diagram assumes that the P controller of the temperature control loop is currently to be computed. Step 3: The algorithm for calculating the function of the P controller is retrieved from the function library in the EPROM. Step 4: The P controller function is now computed in the RAM with the control parameters (x,w,xp) for this temperature control loop. The processor finds these values in the plant memory, which is part of the intermodule buffer. Step 5: The current value thus calculated for the controller output signal, y, is then transferred to the output buffer. Step 6: With the next module cycle, the auxiliary processor receives the new value for y from the output buffer. When the digital code has been converted into an analogue signal, the current controller output signal is transferred to output UO 1 via the demultiplexer.

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19 K /2 RS controller block diagram Summary The block diagram below shows three functional units, from top to bottom: Power supply Auxiliary processor with A/D and D/A conversion Main processor with data and program memories 60004en Auxiliary processor: Motorola 6805, 8 bit AC 24 V DC 5 V POWER SUPPlY DC ±15 V AC 24 V DC 15 V A/D and D/A conversion: 12 bit resolution (4096 steps) Main processor: INTEL 8031, 8 bit / 16 bit structure A D AUXILIARY UNIVERSAL UI MUX MUX UNIVERSAL PROCESSOR UO D A RAM 8 kbytes: Temporary data EEPROM 8 kbytes: Project-specific program with: Structure data Text labels and data tables Other storage, e.g. I/O structure, runtime totalisers, switch-times, parameters etc. DIGITAL DI BAUD- RATE IN MAIN PROCESSOR RAM OUT DO DIGITAL EPROM 64 kbytes: Operating system Function library INTER- FACE RS BUS TERMINAL E - PROM EE - PROM Power supply The DC ±15 V and DC 5 V voltages required internally are produced from the AC 24 V input, but isolated from it. The AC 24 V is transmitted further to power the operator terminal and the DC 15 V is fed to the terminal module carriers, to supply power to the terminal modules. Note The universal inputs and outputs must be set up for either analogue or digital signals during structuring. Auxiliary processor with A/D and D/A conversion The auxiliary processor processes the universal inputs and outputs via the multiplexer. Analogue signals are converted into digital codes and assigned to an operating range %. Digital signals (0 V and 10 V) are assigned directly to 0 % and 100 % of the operating range respectively. Main processor with data and program memories The functions of the main processor are as follows: Processing data to and from the auxiliary processor. Operating the digital inputs (DI) and the digital outputs (DO). Working through the project-specific program from the EEPROM in conjunction with the RAM and EPROM. The following are also allocated to the main processor unit: Real-time clock, with battery back-up Siemens

20 K /2 Baud rate: Speed at which data is transmitted on the RS bus. Baud rate switch: Used to change the baud rate. RS bus interface Allows the connection of the RS controllers, PC interface, pronto interface, operator terminals and the service PC to the RS bus. Siemens

21 K /6 Management of the process variables Measurement and calculation range of the RS controllers The RS controllers can be connected (via terminal modules in the case of the RSM controllers) to a wide range of peripheral devices. Where necessary (e.g. with RSM controllers), the terminal modules ensure that the signals are adapted to the level required by the RS controller. The required signal levels are: DC 0 10 V for analogue operations DC 0 or 10 V for digital operations (digital outputs 0 / 5 V) In the case of analogue operations, temperature sensors with a T1 measuring element represent an exception: their change in resistance is evaluated directly by the RS controller. See page 2, 'Analogue input signals' for more information. The RS controller effectively allocates an operating range of % to analogue DC 0 10 V signals, irrespective of the physical variables and ranges associated with the connected devices. The internal processing in the RS controller is also always within an operating range of %, expressed as a 16-bit value. The RS controller assigns logic 0 and logic 1 to the digital DC 0 V and DC 10 V signals respectively V % AB V Analogue 60005en NK.. 0 V Digital 0 V 10 V Logic 0 / logic 1 10 V NRU.., NRK.. Processing accuracy All analogue values, i.e. all values to universal inputs and outputs are converted, with a resolution of 12 bits (4096 steps). All internal calculated values, setpoints, parameters etc. are handled with a resolution of 16 bits ( steps). The values for the input/display resolution shown in the definition range tables do not affect the internal 16-bit resolution.

22 K /6 Signals at the inputs and outputs This section gives an overall view of the principal options for connection. Mention is also made of special features which affect structuring and the setting of parameters. Refer to data sheet S for details of the measuring principle. Analogue input signals Analogue input signals are derived from one of two sources: Active sensors, e.g. the FKA-V2 air velocity sensor. This already produces a 0 10 V signal corresponding to its physical measuring range of 0 15 m/s. Passive sensors, such as the T1 temperature measuring element. Within the defined measuring range of C, a V signal is generated at the sensor by the appropriate power supply from the RS controller. This signal is converted into 0 10 V in the RS controller. AB = Effective operating range m / s V V V UI % AB The data entered during structuring enables the RS controller to recognise whether a T1 measuruing element is connected. When T1 is defined, the signal is connected internally, via a sensor amplifier C T1 2,23...4,23 V NKDG NKDG 2,23...4,23 V UI % AB NRU.., NRK.. Analogue output signals Signals to modulating or quasi-proportional controlled devices are transmitted to these devices via the UO.. universal outputs and the appropriate terminal modules. The diagram below illustrates three typical examples of connection: Landis & Staefa magnetic valve Modulating damper actuator Motorised valve (or A1H250 damper actuator) with quasi-proportional control Please refer to the notes to the left of the diagram. AB = Effective operating range 60007en * The effective voltage change for an operating range of 100 % for a Landis & Staefa magnetic valve with a DC 0 10 V control signal is approximately 2.5 V (5 7.5 V). This should be noted when setting the parameters (Xp and Offset) % AB % AB UO.. UO V V NKOAS NKOAS M % * % The three-point signal is defined when the output functions are structured. 5 V: STOP motor 10 V: Motor in OPEN direction 0 V: Motor in CLOSE direction % AB NRU.., NRK.. UO open NKOK close M %

23 K /6 Digital input signals a) Sensor contacts with voltage 60008en open log 1 closed 0 V (low) V (high) NKID 10 V 0 V DI.. log 0 NRU.., NRK.. AC / DC V b) Volt-free sensor contacts 60009en Important In the case of digital input signals, an inversion takes place: Closed N/O contacts (signal level High) produce logic 0 in the RS controller, and vice versa. The same applies to N/C contacts: an open N/C contact (signal level High) will also produce logic 0 in the RS controller. open closed 0 V (low) 24 V (high) NKID 10 V 0 V log 1 DI.. log 0 NRU.., NRK.. Digital signals to universal inputs 60010en Important The RS controller interprets a 10 V signal at a universal input as 100 % of the operating range, and a 0 V signal as 0 %. These quasi-digital signals must be converted into true digital signals (logic 1 or logic 0) during structuring, by use of the appropriate SAPIM function. open 0 V (low) V (high) closed AC / DC V NKID 10 V 0 V 100 % AB UI.. 0 % AB NRU.., NRK.. Digital output signals Note: Connection diagrams for these and other examples will be found in Section 11 of this manual. NRU.., NRK.. log 0 DO / UO.. log 1 0 V 10 V NKOD off on 60011en

24 K /6 Processing in the RS controller tv [ C] [ C] t AU Example: Reset function A reset function is used here as an example of how the process variables are handled in the RS controller. Operating diagram In accordance with the plant specification, the function shown in the diagram on the left is required: The flow temperature t v is to be increased as shown, as a function of the outside temperature t AU. At an outside temperature of 5 C, the flow temperature will be set at 70 C, i.e. 50 K above its original value of 20 C. [K] y SAPIM function The desired reset can be achieved using SAPIM function F1.3. The reset adjustment is defined with cut-in and end points Xa1 and Xe1 and the reset height, H1. The absolute value of the original flow temperature t v (20 C), is subsequently added, using another SAPIM function (F4.1). At a temperature of -5 C, the output of SAPIM function F1.3 is thus a reset value of 50 K H Xa1 Xe1 [ C] xe SAPIM structure diagram and signal flow The diagram below is an extract showing the structure diagram and signal flow for this example: The outside temperature t AU is measured by the T1 sensor and transmitted via the terminal module to the RS controller. The RS controller converts the measured value received into its operating range of % and transfers this variable as input xe to function F1.3. F1.3 then calculates the curve using the appropriately set parameters, Xa1, H1 and Xe1. The output value, y, is transmitted via plant memory location UZ01 to function F NRU.., NRK.. -5 C T1 NKDG UIØ1 xe F 1.3 y UZØ1 F C % Xa1 Xe1 H1

25 K /6 50 [K] 70 y H Situation in the RS controller The diagram, left, again shows SAPIM function F1.3, with the procedure required for the example used. An outside temperature of 5 C results in a flow temperature of 50 K above base setpoint. The diagram below shows how the RS controller identifies the individual parameters of this function and the form in which the corresponding values are displayed to the user [ C] xe F Xa1-5 Xe1 22,5 % C 0 22,5 100 % UI Ø1 xe f (xe, Xa1, Xe1, H1) = y y K % UZ Ø1 25 % C 0 17,5 100 % UP Ø1 Xa C % UP Ø2 Xe K % UP Ø3 H1 The absolute value of the physical range C is 200 K = 100 %. Within this, 5 C = 45 K = 22.5 %. The ranges and units of the parameters stored in the various registers are transmitted in coded form to the RS controller during downloading. The values in registers UP 01 to UP 03 can, of course, also be read from the operator terminal. The current value of t Au ( 5 C), as described on page 4, has been converted and is stored as 22.5 % in input register UI 01. From the operator terminal, it can be read in the form of a variable expressed in engineering units. When the parameters are set, variables Xa1, Xe1 and H1 are entered in the form of value from physical ranges (e.g. 20 C for Xe1). The RS controller also interprets these as values within its own operating range of % and stores them in the registers shown (e.g. 35 % for Xe1 to register UP 02). When the processor reaches function F1.3 in the program routine, it collects the current values of all the input parameters and connects them in accordance with the algorithm of this function. The result, y, is in turn stored as a percentage value in plant memory location UZ 01, from where it can be read from the operator terminal in engineering units, i.e. 50 K in the example illustrated (corresponding internally to 25 %).

26 K /6 Display on the operator terminal Starting point The operator wants to know the current outside temperature, t AU. This is 5 C and is stored as an internal value of 22.5 % in input register UI 01. The operator terminal displays the reading in C. The section below shows how this is achieved C -5 C 60017en t t AU 0 22,5 UI Ø1 100 % F 1.3 Transfer of data to the operator terminal When input register UI 01 is selected, the relevant data is transferred from the RS controller tables (shown left in the diagram) to the operator terminal. This decodes the data, converts the % value into engineering units and displays the full reading in ordinary text form. RS Controller UI table Operator terminal 60018en The UI range and units table is in the EEPROM. The code T1 represents a measuring range of C. This is how the operator terminal determines the factor required to convert the associated 22.5% in the plant memory. The code will have been entered during structuring. The current values are stored in the intermodule buffer. In this example they were taken from the input buffer. The text labels, entered during structuring, are in the EEPROM. UIØ1 T1 UIØ2 IMB UIØ1 22,5 Text UIØ1 t Outside A B C D -5.0 C t Outside Display (plain text) Conversion Decoding Display format Numerical Init Text 60019en C t O u t s i d e Sign

27 K /4 Description of the operating system Task: Computing process in an operating system. Program for executing a task. Function The operating system controls the routines inside the RS controller and organises and monitors the data traffic to the peripheral devices. It consists of the following four tasks which are processed in parallel, as it were, with four levels of priority: Clock (1), Communication (2), Administration (3), Application (4). Operating system 60020en Clock Administration Communication Application The intermodule buffer (IMB) is an intermediate memory. It contains all data accessed by more than one task. RS bus IMB Inputs/Outputs Brief description of the tasks The clock task is polled by the operating system in a 50 ms cycle. It controls the timers required by the communication and starts the administration task. The 50 ms periods are referred to as the module base cycle. The communication task is a wide-ranging task for the administration and implementation of communication via the RS bus. The communication is controlled by an interrupt circuit and can therefore interrupt the two tasks described below at any time. The administration task is always processed after the clock task. It runs various counters and has synchronisation and monitoring functions. The application task in normal operation, processes the project-specific program (SAPIM).

28 K /4 Timing and priorities The diagram below shows the timing and interdependence of the tasks. With regard to the communication task an assumption has been made. Note the effect on the application task. The RS module cycle comprises the application time and a reserve time. The latter represents approximately 50 % of the module cycle. This is added by the operating system to ensure that the RS module cycle time remains constant despite variations in the duration and frequency of communication. This is important when calculating timedependent functions such as the integral action time Tn of a PI controller. The application time depends on the length and complexity of the SAPIM program (typically 250 ms). 1. Clock task 2. Communication task 3. Administration task 4. Application task Module cycle (100 ms) 60021en Application Reserve RS module cycle RS module cycle Activities in detail The diagram below provides an overall view of the software activities and the way in which they interact in conjunction with the buffers. The "Communications handler" and "Application" tasks are of particular interest to the user, because they have observable results. For this reason they are described in more detail below. Operating system RS- BUS Communications handler Clock Administration Application Task administration Comms.buffer Task distribution Plant operation administration E2 write Timer BSZ I / O 60022en Read Structure Inter- RS Alarm signals. Plant capacity calculation Alarmhandler Time channels Switch Write Menu tree Initialisation Termination Plant memory I / O Prozessor IMB UIN UOUT DIN DOUT

29 K /4 The communications handler The communications handler controls the RS bus and the data traffic via this bus. Outwardly this software module operates in the same way in all units in the RS range, enabling them to intercommunicate. The communications handler has two basic functions: 1. It receives communication tasks from other units. In this situation, the RS controller functions as a communications slave. The task is passed on to the Task administration function, which performs the appropriate activities and sends back a response. These activities comprise: Reading and writing for operating purposes, and the provision of the menu information required. Structuring, i.e. downloading the project-specific program into the RS controller or application module. These communicaton tasks are transmitted in the form of group communications, i.e. all connected units receive the messages simultaneously. 2. It distributes communication tasks to other units. In this case, the RS controller operates as a communications master, and the Task distribution function can execute these tasks within a given time. The tasks are: Inter-RS communication (2) and alarm signals (1). The order of priority is shown in brackets In both cases, the data is retrieved from or stored in the intermodule buffer. An additional communications buffer holds the incoming and outgoing communications package in each case. The application The Application task has various functions depending on the operating status of the RS controller, i.e. normal operation, structuring mode or service mode. The alarm handler collects the alarm reports and transmits them to the IMB. See K for allocation of registers in the plant memory. Normal operation In normal operation, the application processes the following: 1. Infrastructure, Section 1: This section comprises the I/O processor and the alarm handler. These are always processed completely, as the first step. 2. Plant operation administration: This comprises the following three operations: Initialisation, in which the plant memory is compiled from the intermodule buffer. The plant memory is an internal working memory for calculating the plant capacity and contains all the data required for this purpose. Plant capacity calculation, in which all the calculations required for control and interlock of the HVAC plant are performed. Termination, whereby the plant memory, updated on the basis of the calculations, is stored in the intermodule buffer. The plant operation administration function is also processed completely.

30 K /4 Delays are most frequently caused by the communication. 3. Infrastructure, Section 2 This comprises the following: 8-channel time clock Run-time totaliser Timer module Baud rate switch Section 2 of the infrastructure is also processed completely provided there have been no interruptions in the previous sequences. If, however, a delay has occurred, processing only continues for as long as the RS module cycle time permits. Once processing of a unit has begun, however, it is always completed. 4. Reserve: The reserve time takes up approximately 50% of the plant capacity calculation function. The purpose of the reserve time is to ensure that the RS module cycle time remains constant despite interruptions from the communication. Structuring mode Structuring mode is activated directly via the service socket under software control which automatically disconnects the RS controller concerned from the RS bus. All outputs are set to 0 during structuring. The plant program is downloaded into the EEPROM during structuring. If an error occurs in an application task, which prevents further processing despite several attempts, the RS controller automatically changes over to Service mode. Service mode This is activated automatically when an unstructured controller is switched on. It comprises: Reading inputs and outputs via communication Overriding the outputs via communication Reading the baud rate switch setting Setting the clock and programming the time channels

31 K /6 Communication / RS bus NBRN NICO/NITEL 16 NRU.. NRK.. NIPRO Network topology Principle Multi-point system with serial bus Maximum 32 bus users, all able to intercommunicate Allocation of addresses: No : RS controllers (types NRU.., NRK..), interfaces to PRONTO IRC (NIPRO). No : Operator terminals (NBRN..), interfaces to PC operator station (NITEL..), to MS2000 (NICO) and to TS1500 and MS1000 (NITEL..). Each address may be used only once. Bus and interfaces in accordance with EIA Standard RS485 Implementation For remote RS controllers: bus cable with adapter. For adjacent RS card modules (RSM controllers): bus connection established through spring-contact strip in base Bus-termination is integral to all devices for connection to the bus ('participants') Bus cable: 2-core, twisted See K for detailed specification and connection diagrams o = Intelligence of bus user ('participants')

32 K /6 Important Do not connect the bus cable in a closed ring configuration. Options for arrangement of the bus cable The bus cable may be arranged in any configuration: A Straight point-to-point connection B in a ring configuration. Note, however, that the ring must not be closed. C As a star-shaped network The length of the bus connection between the furthest participants (i.e. from (a) to (b) each of the diagrams below) must not exceed 2400 m. A a b a a Note Normally, when a participant drops out of a network, the communication is either partially or completely terminated. This is not the case with the RS bus system in conjunction with the appropriate organisation of data traffic (see page 3). Within the specified limits, moreover, any number of participants may be removed or connected. B b C b

33 K /6 Data traffic organisation The two basic communication modes Individual communication: During normal operation, a participant, A, (e.g. an operator terminal) may require certain information from another participant, B (e.g. an RS controller). Participant A transmits a call (1) to participant B and receives a response from B (2). Group communication: With group communication, the sender (e.g. A) transmits data intended for more than one participant (X, Y) on the bus. This is the case for the following tasks: Inter-RS communication Time synchronisation Alarm signals In the case of group communication, the sender does not receive a reply from the participants. A A 1 X 2 B Y The three states of the communications handler The devices connected to the bus can each assume one of the three following states: Bus master (BM) Communications master (KM) Communications slave (KS) BM KS KM KS KS KS Note When a device is first connected to the bus system, it may take approximately 10 seconds until it is operative. This length of time must therefore be allowed to elapse before values, for example, may be interrogated from an RS controller. Bus master The bus master status is a virtual function. It is automatically assigned to the device with the fewest communication tasks, which can therefore assume additional tasks. The task of the bus master is to control the data traffic on the RS bus, i.e. bus administration, which consists of the following activities: Checking the topology Allocating the communications master function The topology is checked approximately every 10 seconds. This is the first activity of the bus master, which polls all 32 addresses in the bus system in succession, and checks whether they are in use. At 9600 baud, this procedure takes approximately 0.5 s. The communications master function is allocated to one of the participants in accordance with a priority system described in a later section. Communications master Only one device in the bus system has the function of communications master at any given time. Only the communications master is able to transmit (and of course receive a reply, in the case of individual communication) via the bus. The time allowed for transmission (and receipt) of data is however restricted to approximately 200 ms, after which the function of communications master is assigned to another device. Communications slave All other devices are communications slaves and are only able to receive communications and to respond when interrogated.

34 K /6 Priority levels One of eight priority levels is allocated to each of the stations on the RS bus. The order of priority runs from 0 to 7, with 0 representing the lowest priority and 7 the highest (most important). The standard allocation of priorities depends on the type of station, and is as follows: Type of station Priority RS controller 2 NIPRO 2 Operator terminal 4 lowest 60029en Priority levels Stations connected 17 1 highest Principle for allocation of the communications master function The following principle provides the basis for allocating the communications master function: The higher the priority, the more frequently (n + 1) within one cycle the communications master function will be allocated to the associated stations than to stations at the lowest priority level. A cycle is complete when each station has received the communications master function at least once. The stations at the lowest priority level form the basis for the multiplication factor n, where n = 1. The factor is raised by 1 for each higher priority level, even when intervening priority levels are not used. The communications master function is always allocated first to the first address at the highest priority level. Example The following is an illustration of the principle described above. The table on the left shows the stations connected to the RS bus, namely: 5 RS controllers, Addresses operator terminals, Addresses 17 and 18. The priority level 2 stations have a factor of n = 1, as there are no stations with a lower priority. The stations at priority level 4 have a factor of 3. The frequency with which the communications master function is assigned to the individual stations is therefore as follows: RS controllers : once each Operator terminals 17 and 18: 3 times each The order in which each of the stations receives the communications master function is also worked out systematically. The procedure is not explained here, but the diagram on the left shows the order which would apply to the example Timing It is naturally of relevance to know how long it is before a device is again able to communicate on the bus (e.g. in the case of an RS controller, to transmit an alarm or an inter-rs message). From the description above and the explanations on page 5, however, it will be seen that absolute values cannot be calculated. The timings depend on a range of factors in addition to the topology and the priority levels. Important Activities in relation to alarms must be dealt with in the RS controller concerned. Do not use inter-rs traffic for timecritical signals.

35 K /6 Bus activities General notes on data traffic In normal operation, three activities are processed on the bus: Allocation of the bus master function (BM-Z) Bus administration, consisting of topology check (BV-T), allocation of the communications master function (KM-Z) and the return of the same (KM-R). Communication (K) among the participants. The allocation of the bus master and communications master functions, and the topology check are described in the previous section. This section below gives details of communication among the participants in both operation and group communication modes Key to diagram K Communication KA Communication task BM-Z Allocation of bus master function BV-T Topology check KM-Z Allocation of communications master function KM-R Communications master function returned K K K BM-Z K BV-T K K t KM-Z KA KA KA KM-R The communication tasks In principle, the communications master function is allocated to a station for a duration of 500 ms. The station concerned can execute several communication tasks (KA) in this time. The station itself monitors the 500 ms period. If it establishes, after a communication task has been executed, that the time has not yet expired (e.g. only 490 ms used) it starts a further task. The station does not relinquish the communications master function until this task (including a response where applicable) is completed. This means that in effect, the time for a communications packet (K) may be considerably more than 500 ms, bearing in mind that there are responses comprising up to 255 bytes which alone require 255 ms (at 9600 baud). t