Modbus TCP communication with Allen-Bradley PLC

[sayahan2003]

Hi my friends,
I am trying to connect and OMNI 6000 flow computer to the Allen-Bradley PLC via prosoft card. I can read the OMNI input registers in the PLC with no problem. But the problem is, I can not read the input status from OMNI. For example, the address of the status bits of transmitters in OMNI starts from 1124. I use FC2 (Function Code 2) to read multiple input and put it in register 2000 of Prosoft card in PLC. But I receive nothing. I know that the value of the bits in OMNI are not 0 but I just receive 0 at prosoft. Do you know what the problem is?

Thanks

 

[sthompson]

It has been a while since I did an ProSoft Modbus card. I recall that the correct Bit Address is a bit confusing for FC2 and FC15. The Address has to be specified to the Bit Level, and it is Modulus 16.

So for 1124 try 1124*16 = 17984.

This is all from memory, if I have a chance I will try an pull up the project I did the Modbus in, and try and refresh my memory.

Stu....

 

[sayahan2003]

WOW!!!That worked!!!

Great Job! I really appreciate it.