Passing Modbus on POM

[eman5oh]

How does one send and receive modbus data via a BX-P-ECOMLT?  I see you select @POM in the MWX and MRX instructions, but I can't seem to get it to work? I looked for documentation on this as well and came up empty, can someone point me in the right direction?

Thanks!

[franji1]

How does one send and receive modbus data via a BX-P-ECOMLT?  I see you select @POM in the MWX and MRX instructions, but I can't seem to get it to work? I looked for documentation on this as well and came up empty, can someone point me in the right direction?

Thanks!

The ECOMLT only supports Modbus/TCP as a Server.  The ECOMEX POM can be a Modbus/TCP Client (or Server).

[eman5oh]

I have the ECOMEX as well and could not get that one to work either, how do direct he MRX or MWX to use the PCOM?

[franji1]

I have the ECOMEX as well and could not get that one to work either, how do direct he MRX or MWX to use the PCOM?

Basically, the ECOMEX is a second subnet on the "internal ethernet port".  So, in the MRX/MWX choose the @IntModTCPClient.  If you have properly configured subnets, then the IP Address of the Slave device will direct the TCP out the proper subnet hose.

Say the top port is configured as
192.168.10.5 subnet 255.255.0.0
and the ECOMEX is configured as
10.0.1.22 SUBNEET 255.255.0.0

If your MRX tries to talk to a slave at address
192.168.10.42
it will go out the top port.

If your MRX tries to talk to a slave at address
10.0.1.99
it will go out the ECOMEX POM port.

Just make sure the two subnets (Top port and the ECOMEX POM) are DISJOINT and have NO ADDRESS OVERLAP.

The ECOMEX is technically not an ECOM "module", it is an extension of the onboard Ethernet.  Hence, it can be used as a CLIENT (not just a server) for various other TCP protocols on the CPU (EMail, Ethernet I/O, EtherNet/IP, et. al.).  The IP address routing "just works".

[eman5oh]

Thanks, that makes sense. I had overlap in the subnets. Is how these work documented anywhere?

[franji1]

Thanks, that makes sense. I had overlap in the subnets. Is how these work documented anywhere?

Look at the details on the specific BX-P-ECOMEX POM in Help Topic DMD0497 Pluggable Option Module (POM) Configuration.  That specific POM is discussed towards the bottom of the page.

FYI, the @POM option in the MRX/MWX is for the Serial (Modbus/RTU) based POMs.  Sorry for the confusion.

[eman5oh]

Thanks, that makes sense. I had overlap in the subnets. Is how these work documented anywhere?

Look at the details on the specific BX-P-ECOMEX POM in Help Topic DMD0497 Pluggable Option Module (POM) Configuration.  That specific POM is discussed towards the bottom of the page.

FYI, the @POM option in the MRX/MWX is for the Serial (Modbus/RTU) based POMs.  Sorry for the confusion.

Thank you, the help is much appreciated!