adccommunitymod (AutomationDirect) asked a question.
RS485 Multi-Drop Connection
Created Date: February 10,2018
Created By: dslusser
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Does anyone have a good document or diagram to connect multiple devices to an RS485 drop? I am using a BRX PLC, and for the first time, attempting a multi-drop on the BRX's 485 terminals. Even though its only two devices, I don't want to cheap out and just buy the 2nd RS485 port for the plug-able BRX port.
Created Date: February 10,2018
Created by: dslusser
Does anyone have a good document or diagram to connect multiple devices to an RS485 drop?
I am using a BRX PLC, and for the first time, attempting a multi-drop on the BRX's 485 terminals. Even though its only two devices, I don't want to cheap out and just buy the 2nd RS485 port for the plug-able BRX port.
Created Date: February 11,2018
Created by: pbw
You can enable 120 ohm termination on the PLC in the configuration menu.
You will have to set a unique device ID for each slave.
Hope this helps.
Created Date: February 12,2018
Created by: dslusser
So just parallel the 3 wires, and enable the terminator?
Sounds good to me.
Created Date: February 12,2018
Created by: bcarlton
Be sure to use RS485 rated cable. If you are sure you have everything hooked up correctly and parameters set correctly and still don't have communication swap 'A ' and 'B ' connections at one end. Verify with a master and one slave at first for multiple slave connections.