Two floboss 503 is being interfaced with the SCADA system trough RS485 physical network and Modbus RTU data framing in multi-dropping method. During data reading when last slave connected in the loop the in between GFC stopping to communicate with the SCADA. Advice to resolve the issue highly appreciated

 

You may have the slave(s) set for too much key down timing. In RS485 timing is critical. If you do not have an adjustable slave key down timer THEN try increasing the Host Key Up Delay Timer. Either way you want to have sole ownership of the RS485 pair when a device, master or slave, transmits.

 

Thanx for your reply, Since i am new in this field, i am not having the clarity about your reply. Could you please narrate how to do the changes in the ABB AC 800 F controller side or slave equipment side as you mentioned in the earlier reply?

Looking for your reply and help.