andre.umbul Posted June 27, 2013 Report Share Posted June 27, 2013 I have two redundant OPC servers that will need to access my V130 PLC simultaneously. I have setup two Modbus IP config and two Modbus IP SCAN_EX block with different Network ID and different ports (502 on socket 2 to Network ID 255 and 503 on socket 3 to Network ID 254). Looks like it will only work when only one of the master is active. When both of the masters are active the last one to connect will not be able to connect. Does anyone have a work around this? Do I need to only activate one SCAN_EX per scan cycle? Thanks in advance Andre Quote Link to comment Share on other sites More sharing options...
MVP 2014 Simon Posted June 28, 2013 MVP 2014 Report Share Posted June 28, 2013 I haven't done this before (two simultaneous slaves) but I don't see why it wouldn't work. The following should be eliminated as possible problems. When you say "connect" do you mean the TCP Socket Connect or the Modbus polling/acknowledgement? I would say the Network ID fields on both configurations need to be 255. Also double-check that your two SCAN_EX blocks are attached to different configurations. You could try enabling them each on their own, as well as together and see what happens. Also post your code, as that will help us find the most likely issues. Quote Link to comment Share on other sites More sharing options...
linxchas Posted June 28, 2013 Report Share Posted June 28, 2013 I think as well that the same network id 255 should be used for both sockets. Quote Link to comment Share on other sites More sharing options...
transpondster Posted December 20, 2013 Report Share Posted December 20, 2013 Hi, have you got it working? Trying to excess1 from local and 2nd from internet with V570 and seems only 1 working Quote Link to comment Share on other sites More sharing options...
MVP 2023 Flex727 Posted December 21, 2013 MVP 2023 Report Share Posted December 21, 2013 I routinely code for systems with simultaneous multiple masters using MODBUS IP over Ethernet and Vision products. I've never had any issue even when the slaves are also masters to different PLCs. My systems get a bit complex due to the 4 socket limitation and I've created all kinds of crazy situations to shuffle data around to all parts of the system. One difference is that all my PLCs are always on the same subnet - I don't have any experience connecting across different subnets or across the internet. Quote Link to comment Share on other sites More sharing options...
transpondster Posted December 22, 2013 Report Share Posted December 22, 2013 thanks , yes seems to work, stupid configuration error, thats what you get working at 9PM Quote Link to comment Share on other sites More sharing options...
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