H2-DM1E Communication Issue

[Saturn_Europa1]

My facility has a DO-More H2-DM1E controlling 6 GS2 and GS3 VFDs over ethernet over unmanaged switches and GS-EDRV100s.  The switches are SE-SW8U, 8 port automation direct switches that are linked together with an ethernet jumper. The DO-More is also linked with ethernet to 3 C-Mores around the plant over the same unmanaged switches. 

Every two or three months the DO-More will stop being able to control the VFDs and the GS-EDRV100s will stop showing good communication.  The PLC will still communicate with the C-Mores.  But the VFDs will not respond to commands from the PLC.  To get the VFDs back online we have been power cycling the PLC.  This has been going on for over 4 years.

The errors on the CPU are:

Network stack resource allocation failed - $CommStackOverrn (ST146)
One or more user network devices was forcibly purged to free network resources -  $QueuesFlushed (ST145)


Any ideas what could be the root cause?

 

[BobO]

My facility has a DO-More H2-DM1E controlling 6 GS2 and GS3 VFDs over ethernet over unmanaged switches and GS-EDRV100s.  The switches are SE-SW8U, 8 port automation direct switches that are linked together with an ethernet jumper. The DO-More is also linked with ethernet to 3 C-Mores around the plant over the same unmanaged switches. 

Every two or three months the DO-More will stop being able to control the VFDs and the GS-EDRV100s will stop showing good communication.  The PLC will still communicate with the C-Mores.  But the VFDs will not respond to commands from the PLC.  To get the VFDs back online we have been power cycling the PLC.  This has been going on for over 4 years.

The errors on the CPU are:

Network stack resource allocation failed - $CommStackOverrn (ST146)
One or more user network devices was forcibly purged to free network resources -  $QueuesFlushed (ST145)


Any ideas what could be the root cause?

At the simplest, that error means that the PLC has consumed all of its packet buffers and has done some garbage collection in attempt to recover them. As to what might be causing that, there are many possibilties. We have some advanced diagnostics in the PLC that can help determine the cause. We are happy to guide you through that if you want to contact us at the support email.

[Saturn_Europa1]

I sent them an email, thanks. 

An interesting detail that I didnt mention.  The H2-DM1E is plugged into a D2-09BDC1-1.  On the last slot there is an H2-ECOM100.  Both the H2-DM1E and the H2-ECOM100 are plugged into the unmanaged switches.  The IP addresses in my records show that the CPU is 10.0.1.152 and the ECOM is 10.0.1.119. 

Its my understanding that a H2-DM1E doesnt need a H2-ECOM100. Could this be causing an issue?