FLX - Pro-Face ethernet comms

[ejessen]

A FlexLogix cpu 1794-L/34A is using a Ethernet module 1788-ENBT/A to communicate with several Flex-I/O racks and one Pro-Face GP2500S HMI.

When the HMI is connected the HMI returns the fault code 01:0204 from the PLC. This is and extended error code from the MSG instruction set, saying "Unconnected Message". This message appears after several (5+) hours and has been delayed from 2+ hours after changing the "Send Wait Time" in the comms setup for the HMI.

According to Pro-Face the HMI will communicate as fast as possible (for the HMI) with the cpu in order to update for alarms etc.

As I see it, the maximum of 16 messsage connections that the FlexLogix can handle at a time has been exceeded. Normally I would detect the problem in the cpu and pause the communication, but as the HMI is the one initiating the communication, I do not have that option - or what?

Any ideas to how to handle this situation?

 

[ejessen]

It seems that the nax number of connections has been exceeded.
FlexLogix version 12.x or higher can handle 64 connections.

My theory now is that the HMI starts a new connection every time it needs information. As it is the HMI that initiates the connection, the PLC have no control over this.
So maybe the 'old' connections time out and become available again, but the HMI initiates connections just a little bit faster than the connections time out?

I can then solve the problem by optimize the connections to my Flex-I/O's. Make them Rack-optimized, that is. And thereby decrease the number of used connections and make more connections available for the HMI.

Is there a way to adjust the time out of the connections? Or is there another way to close the connections faster? The problem here is that the communication is initiated by the HMI and not the PLC.