Hydrogen-FC Ltd.

This system working very well to perform the analog data acquisition (temperature) from many RTD to PLC SLC500 Allen Bradley via ADAM-4015, PROLINK-5201/5202-MNET-MCM(4) and PROSOFT-MVI56-MCM. The advantages of this acquisition system are: we could cost-down the using of analog cable, possibility of high speed data transfer until 100 Kb/s – 10Mb/s for long distance way (approximately until 1200 meter), possibility using redundancy concept to optimize and validate data collection from field instruments, reduce the complexity of analog cable installation and noise from unwanted signal (induced noise, ground level differences, impedance mismatches, failure to effectively bias for idle line conditions). You know that analog signal very sensitif from noise.

The change of resistance value when RTD sensing the physical temperature will interpreted and collected by ADAM-4015. Then the RTD acquisition will redistribute on unique Modbus address (4xxxx) and convert the resistance value into unsigned integer (0 – 65535) data.  Each ADAM-4015 could configure separately using ADAM 4000-5000 Utility Software (support for all of ADAM 4000 s/d 5000 series). This software could configure the Modbus (hexadecimal standard) address, baud rate, modbus type, scaling of temperature range on each ADAM-4015. Beside that, its also could monitor the actual change of resistance value of RTD into hexadecimal data view when ADAM-4015 connected with PC via serial/RS-232 port. Because ADAM-4015 only support Modbus 485, you will need converter RS-232 to RS-485 to perform the ADAM-4015 configuration. You may use ADAM 4520 to configure ADAM-4015 using your laptop or PC.

ADAM-4015 communicate with other device using Modbus 485 Master/Slave. This standar industrial protocol have more advantage, like support high speed data transfer until 10 Mbps (bit per second) for long distance (theoritically 1200 meter or 4000 feet)  on base EIA (Electronics Industry Association) standard and could receive resistance  from RS-485 cable up to 12 k ohm. As theoritically, Modbus 485 could have 247 unique node address. Its mean that in one Modbus 485 network, we could have 247 ADAM-4015 that collect data from 1482 RTD. As you know RS-485 cable are 2-wire, half-duplex, multi-drop system. For comparation, imagine how long analog cable that needed when we use analog cable for 1482 of 2 or 3 wire RTD into analog module of SLC500.

On this system, protocol Modbus 485 Master/Slave are used for communication between ADAM-4015 and PROLINK-5201/5202-MNET-MCM(4). When we talk about Modbus Master/Slave network, we have active device that request and collect data from slave device (called by Master Device – PROLINK-5201/5202-MNET-MCM(4)) and passive device that just follow the request from master device (called by Slave Device – ADAM-4015). We could have many slave device for one master device.

After we have finish ADAM-4015 configuration, we should configure the PROLINK-5201/5202-MNET-MCM(4) as the master device. The configuration could perform by Prosoft Configuration Builder (PCB) Software. In my configuration, I set port 0 for Modbus 485 communication with ADAM-4015.  You could download my example configuration by click this link : 2nodetoprolink020908success.ppf.

As the information, PROLINK-5201/5202-MNET-MCM(4) have 4 available input port that support with Modbus 485/422/232 protocol where each port could configure separately.  If we talk about temperature data acquisition from RTD via ADAM-4015, PROLINK could collect a wide amount of data, approximately : 247 x 6 x 4 = 5928 temperature data from RTD. On PCB software we also should write a request command per Modbus address so data acquisition from each ADAM-4015 could collected into PROLINK and save temporary. You could see my configuration on upper screenshot.

Data that have saved temporary on PROLINK-5201/5202-MNET-MCM(4) will sent to PROSOFT-MVI56-MCM using Modbus TCP/IP protocol.  Its mean that each device should have IP, Netmask and Client/Server status configuration. All of configuration could performed by PCB software. Because all of data from ADAM-4015 collected and save temporary with active command in PROLINK-5201/5202-MNET-MCM(4), this device has Server status. PROSOFT-MVI56-MCM just receive data that was sent by PROLINK, so this device has Client status. This is the example configuration of PROSOFT-MVI56-MCM : 1nodetoprosoft020908success.ppf.

As note: PROLINK-5201/5202-MNET-MCM(4) using signed integer (-32768 s/d 32367) and ADAM-4015 using unsigned integer (0 s/d 65535) standard data. The different standard data does not matter on data exchange between ADAM-4015 to SLC500, but we should add scalling function in ladder programming on SLC500. On RSLogix PLC Software available Scale with Paramater function. If you have any questions or more technical support please don’t hesitate to contact me.

Tags: Modbus, PLC/PAC