KB86623
Published: March 27, 2017
Revision: 1.0

Can't read or write to analog points when there is an open comm handle to a missing serial communication module


Applies To:

SNAP-PAC-R1
SNAP-PAC-R1-FM
SNAP-PAC-R1-W
SNAP-PAC-R1-B
SNAP-PAC-R2
SNAP-PAC-R2-FM
SNAP-PAC-R2-W
SNAP-PAC-EB2
SNAP-PAC-EB2-FM
SNAP-PAC-EB2-W

Versions Affected:

Versions affected: I/O coprocessor firmware lower than R3.0a
Problem is fixed in version: I/O coprocessor firmware R3.0a

Resolved In Version:

Problem is fixed in version: I/O coprocessor firmware R3.0a


Symptoms:

If a PAC Control strategy has an open communication handle to a port whose associated rack position is empty:

  • Any writes to analog points will fail without logging or reporting an error.
  • Any reads of analog input points will return a value of -1.#QNAN.


Workaround:

Make sure that communication handles are properly configured, and don't remove SNAP-SCM modules from a rack while a strategy that uses the modules is running.

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


DISCLAIMER

This Opto 22 Knowledge Base ('OptoKB') article is intended to provide general technical information on a particular subject or subjects and is not an exhaustive treatment of such subjects. Accordingly, the information in this OptoKB article is not intended to constitute application, design, software, or other professional engineering advice or services. Opto 22 may modify the OptoKB articles at any time. Before making any decision or taking any action which might affect your equipment, you should consult a qualified professional.

OPTO 22 DOES NOT WARRANT THE COMPLETENESS, TIMELINESS, OR ACCURACY OF THE DATA CONTAINED IN THIS OPTOKB ARTICLE AND MAY MAKE CHANGES THERETO AT ANY TIME AT ITS SOLE DISCRETION WITHOUT NOTICE. FURTHER, ALL INFORMATION CONVEYED HEREBY IS PROVIDED TO USERS 'AS IS.' IN NO EVENT SHALL OPTO 22 BE LIABLE FOR ANY DAMAGES OF ANY KIND INCLUDING DIRECT, INDIRECT INCIDENTAL, CONSEQUENTIAL, LOSS PROFIT, OR DAMAGE, EVEN IF OPTO 22 HAS BEEN ADVISED ON THE POSSIBILITY OF SUCH DAMAGES.

OPTO 22 DISCLAIMS ALL WARRANTIES WHETHER EXPRESSED OR IMPLIED WITH RESPECT TO THE INFORMATION (INCLUDING HARDWARE, SOFTWARE, AND/OR FIRMWARE) PROVIDED HEREBY, INCLUDING THE IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE, MERCHANTIBILITY, AND NON-INFRINGEMENT. Note that certain jurisdictions do not sanction the exclusion of implied warranties: thus, this disclaimer may not apply to you.

Copyright © 2018 Opto 22. All rights reserved.