Modbus Plus with SLC, Prosoft, ABB


Thread Starter

Alex Poulette

I need to address 7 ABB VFD's via ModbusPlus with
an SLC 5/05 and I'm using a modbusplus communication card from Prosoft (3350MBP). I used the code that they supply on their web site but it still not working and I have already spent a lot of time on that. I don't know if it's a problem with the drive or with the communication adapter or with the program? I would like to have some feedback from people that have worked with that kind of stuff. Is it supposed to be easy or the problem is at 18 inches in front of my laptop???


You should be able to troubleshoot this system in two parts (Network hardware and System programming). The key to MB+ networks is generally in their construction pay attention to minimum (10')distances and terminations (continuity through the connection and terminating resitors in the correct location). Once this is established the blinking lights at each of the units should be all you need to finish your evaluation of the network. As far as system programming is concerned that's a matter for the two vendors to help you with MB+ is pretty easy to use. See the modicon web site if you need a MB+ installation guide.

Luis Cardona Sanchez

You need to see first if the ID node of your module is't in the modbusplus network, now if you have the correct configuration cable, check the specifications of the configuration cable, may be is rs232 modbus i don't remember at the moment.
If you don't know how Node you have in your module, you can upload from module in the action module... but you need to see after if have the correct parameters in the Comm config, in the communications menu

Chris Kellock

The Prosoft card works great for communicating Modbus Plus to a Modicon PLC, but I have never tried it to a drive. I just got done building a demo with a SLC503 and Modicon Quantum on Modbus Plus, and it works great. There should not be a problem with the drive.
You didn't say which comms protocol 232, 422 or 485?

What cable pin-out have you?
Are you a master and the drive a slave?
What node numbers are you using?
What are the LEDS's doing on the card?

I've used this card successfully with lots of wierd 3rd party devices and it can be a complete *!@$# to get working but once it works it is fairly reliable.

Termination resistors may not be required if built in to end device.