E1 or E2 periodically does not respond to a command (Ethernet)

Applies To:

Firmware for: E1, E2

Versions Affected:

All versions

Symptoms:

This issue is infrequent and only occurs roughly 0.01% of the time for E2 brains and 0.00001% of the time for E1 brains. If your control program is communicating to an E1 or an E2 using Ethernet, then periodically, you may observe that the E1 or E2 does not respond to a command, but it will normally respond to the next command. If your control program is a PAC Control strategy, you will typically see the following:

If the E1 or E2 is configured for 2+ tries, -539 error will show up in the controller’s message queue.
If the E1 or E2 is configured for only 1 try, the message queue will have a -539, followed by a -534 and a -58 error, and the controller disables communication to the E1 or E2.

Workaround:

Do all of the following:

Modify the control engine communication settings for the E1 and E2:
1. In PAC Control, open the Edit I/O Unit dialog for the E1 and E2.
2. In the Communication from control engine section, update the values for "Timeout and disable communications" fields:
  - For "after ___ tries", specify 2 (one for the initial command, one for a retry).
  - For "of ___ second(s) each", specify 0.5. For networks with higher latency, you may need to increase this value.
For PAC Control strategies, add I/O enabler logic as demonstrated in the I/O Enabler for Ethernet and SNAP PAC Brains sample.

Resolution:

Opto 22 is investigating this issue.

Questions?

Contact: Opto 22 Product Support.
Phone: 800-835-6786 or 951-695-3080
Email: support@opto22.com

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