Trying to get communication to the Sepam relay over RS485.
If the green led stays lit on the ACE9xx module that means there is a comms wiring issue. For normal working conditions, the green light would be:
a) turned off when Stand-By i.e. Commubnication frame to SCADA
b) flickering when communicating to SCADA
In order to fix the wiring issue, verify:
a) That the module is not grounded more than once. Often, the shield is exposed and grounded unnecessarily with the clamp, which is located below the terminals. Make sure that the shield isn't exposed and touching this clamp.
b) That the RS485 terminals are wired correctly. Here are the wiring diagrams for 2-wire and 4-wire communication:
For 2 wires:
Warning: L+ connects to L- and vise-versa when communicating to a powerlogic or third-party device on the same daisy chain!!!!
For 4 wire: