How do i setup communication between the ABB System and Radio frequency Sytem?

I want to configure CI853. I need to pull signals from a radio (TRANSPARENT MODEM) that talks Modbus protocol. The port from this modem is DB9 and the CI853 card has rJ45 port on it. I have modified a cable which is DB9 on one end and rJ45 on the other end. I still cannot get any joy onto my communication. The parameter "VALID" on the Modbus Connect block on my program is still "false". I believe i need to get this parameter true then i can start setting my registers properly for pulling data across. What do i need to do? Please help.

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asked 1 year ago



> "What do i need to do?"

- Read the manuals, especially the comm protocols

- Use the example Modbus App that you can download from this site

- Use the AC800M Programming cable to connect the CI853 to a standard serial port

If Polling is enabled on the MB link then the remote PLC must respond to a Poll request before the MBconnect goes valid. Set the poll interval to zero to disable polling and check if the MBConnect goes valid. If not, you havent configured the AC800M side properly yet.

Rob Lyon   

answered 1 year ago


By Smgobhozi on 3/6/2017 | Like (0) | Report

Hi Rob

I have used the programming cable and if I disable polling, comms becomes valid but I still cannot receive signals from the transmitting side of the radio. As soon as I set the polling time to 4 seconds, comms goes unvalid. Can it be possible that this radio unit can never be able to talk to our ABB system at all.Still have no joy.

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In addition to Rob advices (also many other issues for that in the forum):

1. Cable diagram is shown below

2. Attach MODBUS protocol to your COM port in Control Builder Hardware (e.g. COM1 on CI853 = address 2.1 in channel below)

3. Connect the slave e.g. slave address 2 (try different than 1, 1 usually is master)

4. MBConnect parameters


Channel = Var_ch; string[40]; retain; '2.1'

Partner = Var_partner; string[40]; retain; '2'

ID = Var_ID; ModBusCommLib.Comm_Channel_MB; retain

Note - poll time advise of Rob = 0

If everything is OK, you should have Valid = true. Did you check if both LED's on Rx/Tx are blinking? This will show you phisycal connection.

5. Use pulse generator output at MBRead Req input


answered 1 year ago


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