KB47958
Published: February 26, 2007
Revision: 3.0

From OptoControl, Ethernet-based I/O units may go offline if number of characters waiting not checked before receiving characters


Applies To:

SNAP-LCM4
M4RTU
M4
M4 I/O

Versions Affected:

Problem was discovered in firmware version: R4.1c
Resolution is included in beta version: B4.1d, Build February 14, 2007


Symptoms:

Error –44 is unexpectedly reported in the OptoControl error queue, and Ethernet based I/O units may go offline without reporting an error to the queue. OptoDisplay may exhibit unexplained timeouts, and OptoEnetSniff may not show communication transaction errors.


Workaround:

Use the “Get Number of Characters Waiting on Ethernet Session” command immediately before using the “Receive N Characters from Ethernet Session.” When designating the number of characters to receive, make sure the number is greater than 0, and up to the number of characters waiting.


Resolution:

Opto 22 has resolved this issue.


Questions?

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


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