Can I specify port in Ethernet Comm Control?

[usapatriotforlife]

Hi, is it possible to specify the port number that an ethernet comm control uses when connecting to a PLC?

I looked at the control, but couldn't see how to do this.  I tried adding ":" and the alternate port to the end of the IP address and that did not work.

Thanks!

[Archie]

The port number is fixed to port 0xAF12 as specified in the Ethernet/IP specifications.

[usapatriotforlife]

Hi Archie, 

Thanks for the quick response!  So by fixed, are you saying that it can't be changed somehow in AdvancedHMI? 

[Archie]

No, it can't be changed because it's hard coded in the Data Link Layer. What scenario would you need to change it?

[usapatriotforlife]

That's unfortunate.  I'm involved in a very common scenario (I feel).  I'm surprised this hasn't come up before.

We have PLCS running behind cellular modems in vending machines located in remote rural areas.   Port forwarding is used to translate incoming requests to the cellular modem's public IP to a private non routable IP on the LAN side network. 

We recently added a second vending machine at one of the remote sites.  We want both machines serviced from the same cellular modem.  Therefore, due to the way port forwarding works, we need to connect to another port other than the standard 44818 to signify to the modem's router that the traffic needs to be routed internally to another IP/PLC.