ML1100 modbus talking to a ABB drive

[svarney 0]

i am trying to get a ML1100 to talk with a ACS350 ABB drive. I'm not sure what I am doing. I have it wired up per the instructions from Rockwell's site. Is there a way to test if I'm wire correctly? Does anyone have an example of a program that would pull a word or two from the drive? thanks in advance for the assist. scott

[Ken Moore 23]

How is your message setup, can you post it? What errors are you getting in the channel status tab? Are you using a modem, or is it "hard" wired?

[jimdi4 2]

Are you using DeveiceNet? Usually the Standard protocol to communicate to VFD's such as the ABB drives is Devicenet with AB products. (I don;t know how a ML works with Devicenet...Clogix 5000 uses a Devicenet card and setting it up in the rack) For example, I used ACS 400's this would probably apply to the 350's as well, In the ACS 350 user manual there should be a chapter labeled Standard Serial Communications. In that chapter they layout the Control Word and the Staus word. The Control word to send Start, stop, Inhibit the drive are detailed by bit numbers in the book. The Control Status word to get info from the drive such as Faulted, Running, etc. In the PLC program copy the Control and staus word then you can use the bit level of the word to condition logic. I would give examples but the last time I wrote anything to do this was in CLogix 7.0...I cannot open that program until I get to my older laptop at home... Hope this helps... Edited 8 Apr 2009 by jimdi4

[svarney 0]

I am hard wired from the PLC 485 adapter to the drive. I am getting a time out error. msg_block.doc

[Ken Roach 194]

If this is an FRSA-00 module, you've probably seen the wiring diagram: http://library.abb.com/global/scot/scot239..._01_UM_REVA.pdf RS-485 manufacturers can never seem to agree on Data A and Data B designations, so the general rule is "if it doesn't work, switch terminals". For the Modbus communications, I recommend plugging in a PC to the MicroLogix with a 1761-CBL-PM02 cable and just listening to the data that's sent out of the MicroLogix to verify that it is sending the Modbus commands you think it is. I like RealTerm for a simple, free terminal program, and Chipkin Automation Systems has a free Modbus Parser if you don't want to decode the hex bytes manually.

[svarney 0]

Ken I switched A&B around and now i get a message of DF1 FD- local communications has been lost. Not sure if i improved the issue or made it worse. thanks scott

[swimmy67 9]

It sounds like you have to configure COMM 0 for Modbus Master communications. It looks like you are communicating with the ML1100 by Ethernet so the DF1 Port should have the 1763-NC01 connected to it. You can do a search here and find the communication settings as they have been discussed many times here.

[svarney 0]

Channel 0 is modbus RTU Master while Channel 1 is Ethernet.