Logix5000 I/O : Lesson to be learned

[daba]

Just a heads up on a problem we had on site recently, and how it was solved.


Added some AENTR flex I/O to an existing ControlLogix system, and could not get comms to the AENTR modules, even though we had proved it locally with my training rig.


Turns out the firmware revision of the site's 1756-ENBT was the culprit, requiring at least 4.007, theirs was 3.xxx something.


I only found a KB article on it by chance....



Caveat : Check your firmwares

 

[Ken Moore]

I recently ran into a similar situation, an older installation with 1756-ENBT's could not connect to a new remote panel with ENT2R's. Had to update the firmware also.

So...in a nutshell, the old communication cards need new firmware to connect to newer communication cards.

 

[einnh]

I just had that with their new 5069 series dc output modules. Leakage was higher than anticipated on the closed state. Apparently fixed with a firmware update (found out through TechConnect, I would have never found it in the knowledgebase.).

 

[Geospark]

...Turns out the firmware revision of the site's 1756-ENBT was the culprit, requiring at least 4.007...

I recently ran into a similar situation, an older installation with 1756-ENBT's could not connect to a new remote panel with ENT2R's...the old communication cards need new firmware to connect to newer communication cards.

Yes, the older firmware 1756-ENBT sometimes struggle with nodes that communicate at a faster rate than it can keep up with. Firmware revision 4.007 specifically dealt with this issue...

Release Notes...

Corrected Anomalies with Revision 4.007

CORRECTED: When connecting to a device with a more rapid response time (for example, a computer or a 1756-EN2T module), the 1756-ENBT module’s attempt to open the TCP connection may time out.

The timeout occurs because the faster device has sent a reply to the 1756-ENBT module before the 1756-ENBT module socket is fully open and the module is unprepared to receive the reply. The 1756-ENBT module misses the reply and the TCP connection times out.Firmware revision 4.007 corrects this issue by preparing the 1756-ENBT module to receive the reply earlier.

But probably best advised to consider flashing to revision 6.006 latest, where possible.

Regards,
George