ModbusLink M ModbusLink S Operations & Maintenance Manual Part No. 8800-1197 Revision 1.1 May 6, 2015
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 2 TABLE OF CONTENTS 1. Introduction... 3 1.1 Features... 3 2. Unpacking... 3 3. Hardware... 4 3.1 Connectors... 4 3.2 Terminal Block... 5 3.3 Battery Connections... 5 4. Setup and Operation... 6 4.1 Modbus Connections... 6 4.2 ModbusLink Network Basics... 6 4.3 Setup... 8 4.4 Configuring ModbusLink... 9 5. Quick Start Guide... 12 5.1 Generic Configuration... 12 5.2 Node Address Configuration... 12 5.3 Static Address Mode... 12 5.4 Verifying Communication... 12 6. Troubleshooting and Maintenance... 13 6.1 Troubleshooting... 13 6.2 Maintenance... 13
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 3 1. Introduction The ModbusLink is a low power multihop mesh network to wirelessly connect modbus sensor(s) to a Modbus Master. A ModbusLink network consists of one master (ModbusLink-M) connected to a Modbus Master/logger/data recorder and at least one slave (ModbusLink-S). Each Slave unit can be connected to one Modbus sensor via either a RS232 or RS485 port. If the ModbusLink-M is unable to reach a Modbus sensor directly, it will try to discover a route to the destination via intermediate ModbusLink-S modules. 1.1 Features 1 mile LOS range ( longer ranges possible via intermediate nodes/mesh networking) Very low power consumption. All nodes are capable of routing messages, interfacing with Modbus sensor while staying in low power mode ~3.5 years battery life (included) Transparent drop-in Modbus wire replacement. (No special address requirements) RSSI level indication to indicate Signal strength. Multiple Networks can co-exist without interfering with each other. Simple Network commands to configure & maintain network 2. Unpacking Remove the ModbusLink-M and ModbusLink-S units from the shipping container and visually inspect the unit for signs of damage during shipment. Report any such damage to the factory immediately to ensure a prompt response and resolution. Retain one shipping container in the event a factory return is necessary. Please note that if a return is required, a return material authorization (RMA) number is required. To get this RMA number, call the Sutron Customer Service Department at 703 406 2800.
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 4 3. Hardware 3.1 Connectors The ModbusLink-M/S modules support the Modbus protocol (RTU mode) over RS-232(default) or RS-485, selectable via a simple command. The external IP6 rated DB9 connector should be used for communication with Modbus loggers/sensors using RS-232. For interfacing with a modbus logger/sensor over RS-485, a 5- terminal connector is provided. The module can also be provided external power via the 5 pin connector. Please refer to Table 1 for a detailed description of the connector. The ModbusLink modules can be connected to a PC via the 10-pin header J4 using a 10pin to DB9F cable (6411-1382-24) for configuration/debug purposes. Figure 1 ModbusLink ports
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 5 3.2 Terminal Block The ModbusLink modules have a 5 position terminal block that supports plug in screw terminals. The screw terminals are connected to a 5-wire cable which is color coded. Wire color White Green Brown Red Black Description Modbus over RS485-A Earth Modbus over RS485-B 8-16v dc power input Power Ground 3.3 Battery Connections The ModbusLink-M/S has an internal battery to power the unit; however, external power (8-16v dc) can be applied to J3. If external power is applied, the internal battery is automatically cut off and the module runs off the external supply. The performance/functionality of the module is identical, regardless of the power input source. If the external supply is removed, the unit automatically shifts to battery power. This transition is transparent and does not interrupt the normal operation of the module.
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 6 4. Setup and Operation 4.1 Modbus Connections The ModbusLink-M would be connected to a Modbus Data Master/Logger via either the RS232 or the RS485 port. There is no need for further battery connections. From the Modbus sensor s perspective, the ModbusLink-S replaces the Modbus Master on the remote end of the connection. The Modbus sensors would connect to the ModbusLink-S just as they would to a Modbus Master/Logger/ data recorder. The unit supports Modbus (RTU mode) over RS232 or RS485. A simple command can be used to switch between RS232 and RS485 modes. The ModbusLink-M module is shipped with a NULL modem so that it can communicate with a Modbus Master or PLC (RS232 mode only). The ModbusLink-S modules can interface with a modbus sensor using either the RS232 or RS485 port. No NULL modem is required for RS232 mode. 4.2 ModbusLink Network Basics A ModbusLink network consists of ONLY one master (ModbusLink-M) and one or more slave (ModbusLink-S) modules with the same Network-ID. All slave units must have the same Network-ID as the Master in order to be able to be part of the same network. For the purpose of simplicity, the Network-ID can be represented by an imaginary physical wire connecting each ModbusLink module to other ModbusLink modules (within radio range) having an identical Network-ID, in a mesh-like topology. Multiple networks each with their own Master and Slave(s) can coexist within range of each other, provided they have unique Network-IDS. The default Network-ID for all modules (ModbusLink-M and ModbusLink-S) is 15. No two ModbusLink-M modules with the same Network-ID should be within range of each other. When the Modbus Logger sends a Modbus command to the ModbusLink-M module, it extracts the address information from the command and tries to find a ModbusLink-S module with the same address in the network. If the destination node is not within radio range of the ModbusLink-M module, it will try to discover a route via intermediate ModbusLink-S modules. If multiple routes are possible to the destination, the most efficient route will be selected. 3 4 M 2 5 6
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 7 In the preceding figure, consider the example where the ModbusLink-M module receives a Modbus command from the Modbus logger addressed to Modbus Sensor #6.The ModbusLink-M broadcasts a route discovery request to all ModbusLink-S modules in the network. Nodes#2, 3, and 5 receive the discovery request. They each note that they have a path to M. Node# 3, 5 rebroadcast the discovery request. The request is received by Nodes 2, 4 and 6. Node 6 notes it has a path to M through 2 and sends the route complete message to M through 2. Node 4 also rebroadcasts the discovery request which is also received by 6; however, it is ignored by 6 since it already has a superior route. Once a route has been established, data can be sent through the route to the destination node. Data messages are never broadcast to conserve power. They are only addressed to a single node (unicast) which could either be the destination for the message or an intermediate node en-route to the destination as shown below: 3 4 M 2 5 Message Delivery 6 The master will send all data destined for node 6, to node 2. node 2 will in turn forward the message to node 6. The other nodes do not play any role in delivering the message to node 6, thus conserving power. If an intermediate node cannot deliver a message to the next hop, it informs the sender, which starts a new route discovery.
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 8 4.3 Setup Each ModbusLink-S module in the network must have a unique node address. The address of the ModbusLink-S module must match that of the modbus Sensor connected to it. The ModbusLink-S can be configured to operate in Auto address mode or it can also be assigned a static address. The ModbusLink- M module does not need any address configuration. The ModbusLink module is shipped with an internal D-Cell battery that is used to power the radio and communications with a local modbus sensor (if connected). To prevent damage, the internal battery is disconnected before shipping. Unscrew the lid and connect the battery connector to J5 as shown in the figure below. If, using automatic Node address configuration(described below), ensure that the Modbus sensor is connected to the ModbusLink-S at power up. Also ensure that the modbus communication parameters like baud, parity etc of the sensor are the same as ModbusLink-S module. If the parameters are different from the default settings of the ModbusLink-S, refer to the Appendix for details on how to change the Modbus communication parameters. If configured to operate in the automatic address mode, The ModbusLink-S modules will automatically scan the RS232/RS485(based on configured port) ports for a Modbus sensor, during the power up sequence. On receiving a response from the sensor, the ModbusLink-S Node sets it own address to that of Modbus sensor (If no sensor is found, the ModbusLink-S will retry after an hour. If the automatic configuration is not desired, the ModbusLink-S node can be assigned a static address. The static address assigned to each node must be unique throughout the network and match the address of the local modbus sensor connected to it
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 9 Replace the enclosure lid and tighten the screws To prevent damage while shipping, the antenna is not connected to the module. Please screw the antenna to the RP-SMA connector on the top of the enclosure, till it is secure. DO NOT OVERTIGHTEN THE ANTENNA to prevent damage to the RP-SMA connector. 4.4 Configuring ModbusLink The ModusLink module can be configured using a 10-pin to DB9 cable (6411-1382-24) connected to J5. Any terminal program like HyperTerminal (Baud = 5700, parity = none, Handshaking = none) can be used to configure the modules. The general command syntax is <command> = <value><cr><lf> COMMAND VALUE RESPONSE DESCRIPTION Test RS232 communication AT -- OK with module Modbus Com = <value> Modbus Baud = <value> value = RS232, RS485 <value>=57600, 38400, 19200, 9600, 4800 > Modbus Com = value Where value = the new modbus com port >Modbus Baud = value Where value = new baud rate Set Modbus communication port to either RS85 or RS232 Set the baud rate for the Modbus port
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 10 COMMAND VALUE RESPONSE DESCRIPTION Test RS232 communication AT -- OK with module Modbus Parity =<value> Node Address =<value> <value> = odd, even, none <value> = 0 : automatic node address <value> 1 thru 247 : Static address range >Modbus Parity =value Where value = new parity setting >Node Addr = value Where value = new address assigned to the Node Set the parity for Modbus communication Set the node address to either automatic or static address NwId=<value> Nw Scan -- <value> = 1 through 15 >NwID = <value> value = new value for Network ID > Node Address=addr, Hops= hops returns the address and hop count for each node Set the network ID. Must have the same value for all modules in the same network Performs a live Scan and report the address and hop count for all nodes in the current network ver -- Blink Led = <addr>,<time> Factory Defaults =!Sutron! <value> = remote node address <time> = duration in seconds to keep blinking the LED on remote node. If time = 0, the Led will blink forever -- OK >NW Stack Ver=x.xx >Modbus Stack Ver=x.xx >OK : Node blink command sent successfully >ERROR : Destination not found Unable to locate remote node Returns the version number of the modbus stack and network stack Blink the Red LED on remote node for a predetermined amount of time Restores all settings to factory defaults
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 11 Optional Mounting Bracket Kit (2911-1395) The optional mounting bracket kit provides an easy way to mount the ModbusLink modules to a 1.5" standard pipe. The kit includes the mounting plates, alignment bracket and u-bolts/hose clamps and screws to fasten the plate to the ModbusLink modules. The mounting plates are designed to allow other u-bolts and/or hose clamps (not provided) to allow mounting to 1" and 2" pipes as well.
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 12 5. Quick Start Guide The configuration of ModbusLink modules can be broadly classified into two categories Generic configuration applicable to both ModbusLink-M and ModbusLink-S. Node Address config applicable only to ModbusLink-S modules. 5.1 Generic Configuration Open the enclosure lid and connect the module to a PC via the 10-pin to DB9 cable. On the PC open HyperTerminal (baud 57600, parity = None, Handshaking = none) or any other terminal program. Power the module either by connecting the battery or applying 8-16v to the appropriate terminal block leads Issue a test communication command AT. The module must respond with OK To use Modbus in the RS485 mode, issue command Modus Com = RS485. The default is RS232 To change Baud issue command Modbus Baud = <baud>. Refer to the command table for supported baud rates To change the parity issue command Modbus Parity=<parity> Refer to the command table for supported parity types To change the Network ID, issue command NwID=<Network Id> Power cycle the device 5.2 Node Address Configuration The ModbusLink-S modules can be configured to operate in 2 address modes 1) Static address mode 2) Automatic address mode (default) 5.3 Static Address Mode Assigning any node a Non-Zero Node address make is operate in the static address mode. To change the Node address, please follow the following steps Issue command Node Address = <addr>, where addr is the static address of the module. This address must match the address of the local Modbus Sensor. To revert to automatic address mode, set the Node address to 0. Power cycle the module 5.4 Verifying Communication
Sutron Corporation ModbusLink M & ModbusLink S Rev. 1.1 Operations & Maintenance Manual 5/11/2015 pg. 13 If the slaves are configured to operate in the automatic address mode, it is advantageous to have the modbus sensors connected to the slaves before powering up the modules. After powering on the ModbusLink-M and ModbusLink-S modules, wait for about 2 minutes for the slaves to finish scanning for a Modbus Sensor(automatic address mode only). Issue command NwScan and wait for a few minutes for the scan to complete. Ensure that all the nodes are being reported in the scan. To visually Identify a node issue command Blink Led = <addr>,<duration>. This will blink the Red LED on node with address = addr for duration seconds 6. Troubleshooting and Maintenance 6.1 Troubleshooting The following checklist will help in troubleshooting problems: Problem No response from module (PC config) Unable to query remote Modbus sensor Intermittent lost data Nw Scan reports the Node address as a large junk /negative number Possible Cause Ensure that the module is powered and the baud rate and parity are correctly set on the PC side Ensure that the Modbus baud, parity settings on the sensor/logger and the ModbusLink-S/ModbusLink-M are identical Ensure that the Modbus Device (Rs232/RS485) settings are correct If using Static address ensure that the address assigned to the slave matches the address of the Modbus sensor If using automatic address mode, ensure that the Modbus sensor is powered and connected to the ModbusLink-S module before powering it up. Power cycle the ModbusLink-S module. Ensure that all the modules have the same Network ID Ensure that the Antenna is properly secured Ensure that the Antenna is properly secured and that LOS link is available between the node and its neighbor The Node has been configured in automatic address mode and was unable to find a Modbus sensor connected to it. 6.2 Maintenance Maintenance of the unit should be performed at regular intervals which are dependent upon the conditions of use. Typical maintenance for the unit consists of checking the wiring to make sure it is not corroded or frayed and examining the unit to ensure that there is no physical damage.