PLC to PLC Comm issue

[PLC_L 0]

Hi All, I'm having some issue when trying to exchange data between two CJ series PLCs, any dude able help to enlighten me? Here are my setup, slave PLC CJ2x with onboard ethernet port (IP=192.168.1.11) master PLC CJ1x with etn21 card install (IP=192.168.1.10) Both connect via a switch and i'm using cpu011_receivedata FB to retrieve some data from slave PLC, unfortunately the comm doesnt seems work fine for me. Is configuring routing table a must for the comm of both PLC to work? FB configuration: ----------------------- network add = 0 (local network?) node add = 11 unit add = 0 (CPU unit?) Is recv or echrd work for my case? do i need any routing table setup if using either instruction?

[Mendon Systems 22]

You do not need a routing table for connections in the same subnet.

[PMCR 66]

You don't need a routing table if you only have 1 CPU Bus module on the PLC that is sending the FINS command. If you have more than 1 CPU Bus module, and a PLC sends a FINS command to FINS Network 0, it will always go to the lowest CPU Bus Unit Number (the rotary switch on the card). I always suggest (and implement myself) proper FINS routing with a Routing Table. It is a small investment up front. For a quick tutorial on FINS routing, see the Youtube video here.

[PLC_L 0]

Is the Etn consider CPU bus module? Because I'm having two Etn module. So how should I setup the routing table in this case? Both Plc need to create a routing table!?

[Mendon Systems 22]

Yes, if you have more than one ETN module you will need a routing table. Both PLCs will need one.

[PLC_L 0]

Ok, so the cj1x Plc with two Etn on it, and cj2x with onboard Ethernet. I'm using the 2nd Etn to link with cj2x, so i will need to create a local fins network? my Etn unit number configured as 1, then my cj2x unit number must configure the same as Etn? PLC Power cycle require after transferring routing table?

[PMCR 66]

The unit numbers on the 2 plcs communicating do not need to match.The FINS Network numbers assigned to the Ethernet card by the FINS Routing Table do need to match.You do not need to cycle power after transferring a FINS Routing Table. All CPU Bus modules are restarted after a routing table is downloaded.There is a video on Youtube that shows setting up a FINS routing table with CX Integrator. search for FINS Routing.

[PLC_L 0]

Ok thanks a lot for the help. Finally got both Plc in comm. Now I'm facing another problem. The function block retrieve data in int, however the Plc data is in real. I'm trying to get 2 int but the value don't seems to be match with the reading in real.

[PLC_L 0]

And after transfer the routing table to Plc, the first Etn module showing an erh alarm led lid on. Same happen for the cj2 Plc, however no error noticed from the program. Is that normal?

[PMCR 66]

If there were no errors, and downloading the Routing Table caused an error, then the routing table is probably incorrect.

[PLC_L 0]

Ok i found the root cause finally, because i have two etn modules under the same plc, but routing table only configure for 2nd etn, hence 1st etn error. Alarm gone after include routing configuration for 1st etn also. However another concern arise, that is the 1st etn is link to scada(wonderware) network, so i'm abit worry if configure routing table for 1st etn will require any changes from the SCADA site in order to comm?

[PMCR 66]

If the SCADA software was communicating to the PLC without a Routing Table, that means it was configured to communicate using FINS Network Number 0. Any ETN card will respond to commands using FINS Network Number 0, even if the Ethernet card has a FINS Routing Table entry. You should be able to add the first ETN to the Routing Table without causing any probems for your SCADA software.

[PLC_L 0]

Thanks dude, successful added routing table for both etn now and scada is working as usual :)