adccommunitymod (AutomationDirect) asked a question.
Modbus wiring to Allen Bradley
Created Date: November 19,2011
Created By: amotomura
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I have a Sure Servo that I would like to control from an Allen Bradley Micrologix 1400. I can't find a wiring diagram for the Modbus comms. My plan is to use 1763-NC01 on the Allen Bradley side, and would like to eventually network 4 SureServo's. Right now, i just want to get 1 working. I'm sure that this has been done before, but I can't find the pinout diagrams between the 1763-NC01 and CN3. Can anyone help? Thanks in advance, andrew
Created Date: November 19,2011
Created by: bcarlton
You probably won't find one specific diagram showing exactly that connection.
Start with the RS485 Connection Wiring diagram but pay attention just to the Servo connector (CN3). If needed make a copy and cut off the left hand potion going to the DL. Notice you have three wires, TXD+/RXD+, TXD-/RXD- and GND. These will go to the 1763-NC01 terminals 5(A), 4(B) and 3(COM).
When testing, if you are sure parameters are the same but have no communication then swap the A/B connections at the 1763-NC01. Be sure to write down whatever works. (Post it here as a help to others).
Created Date: November 19,2011
Created by: amotomura
Thanks for the quick reply!
How important are the termination resistors? The nc01 has a built in resisitor, but I don't have one handy for the CN3 side...
Created Date: November 19,2011
Created by: bcarlton
We get away with it if drives are very close, at least in the same cabinet. Give it a try.
Created Date: November 19,2011
Created by: amotomura
I have a Sure Servo that I would like to control from an Allen Bradley Micrologix 1400. I can't find a wiring diagram for the Modbus comms.
My plan is to use 1763-NC01 on the Allen Bradley side, and would like to eventually network 4 SureServo's. Right now, i just want to get 1 working.
I'm sure that this has been done before, but I can't find the pinout diagrams between the 1763-NC01 and CN3.
Can anyone help?
Thanks in advance,
andrew