KB51892
Published: July 11, 2007
Revision: 2.0

Unexpected serial I/O unit PID behavior when accessed by an OptoOPCServer client


Applies To:

OptoOPCServer

Versions Affected:

Problem was discovered in version: R7.1a
Problem is fixed in version: R8.0a

Resolved In Version:

Problem is fixed in version: R8.0a


Symptoms:

There is unexpected behavior from a PID on a disabled serial I/O unit when accessed from ioControl by a SNAP-PAC-S1. Some of the oddities include:

  • If the serial I/O unit with a PID is disabled and an external application such as the OPC Test Client, writes to a PID parameter (gain or integral, for example), the IVAL does not change.
  • On an enabled serial I/O unit, if a configured PID is disabled and an external application such as the OPC Test Client writes to a PID parameter, the parameter is changed as expected, but the PID loop becomes enabled (the View PID Loop dialog, ‘Enable comm’ reports “Yes”) and the XVAL also changes. In this case only the IVAL would be expected to change.

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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