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fseipel22

Controller Connectivity Problems

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Good Afternoon,

 

We have two PLC's and (L75), EN2T NICs.  One PLC is redundant.  L75 and L77 CPU's.  Over the last two weeks, we gradually lost HMI communications to ONE of the two PLC's.  Oddly, computer/RSLINX could see topics for ONE PLC but NOT the other.  Finally this was remedied by power cycling CPU. . . But then communications to second PLC, between RSLOGIX and CPU stopped working, while HMI comms was restored.  But now, gradually, we are seeing RSVIEW32 stop communicating -- that is, it stops 'seeing' topics on this second PLC, one workstation at a time.  EVEN THOUGH CPU SHOWS UP IN RSLINX.  When I run the OPC Test Utility, and click 'online', it shows no tags for that controller under 'online', whereas the other controller, shows the tags.  When I attempt to go online with the effected PLC in RSLOGIX, it just gives an hourglass.  Plant is running so my ability to troubleshoot is limited.  RSVIEW32 7.40 here under XP (I know it's very old).

I even tried a separate installation of RSLOGIX on a laptop, same symptoms.  Even tried USB connection.  When I connect USB to network card, and browse to controller, it just gives endless spinning ball/Bill Gates stopwatch.  When I connect USB directly to controller, I also can't go online.

Using mostly Stratix switches.  Also have a Prosoft Modbus card, and an eWeb card.  Problems seemingly came out of nowhere.  Any advice welcome!

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Try browsing to the web page of the EN2T cards. They show a lot of information about connections and such, might give you a clue.

 

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Thank you, I tried this already, but saw no obvious issues.  That is, it was below max connections and under 10% CPU utilization.  There may be red flags that I do not know enough to see.

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