KB89081
Published: September 18, 2020
Revision: 2.0

Analog input channels with non-zero offset calibration show incorrect values


Applies To:

GRV-R7-MM1001-10

Versions Affected:

2.0.0 to 2.0.1

Resolved In Version:

2.0.2


Symptoms:

If you configure an analog channel to report degrees Fahrenheit and set offset to any value other than zero, the channel value will have an offset error proportional to 5/9ths the desired offset. This applies whether you configure I/O through:

  • groov Manage (from the groov Manage Home page, click I/O Channels, then the channel number)
  • PAC Control (in the Edit Analog Point window, in the Send Values group)

Example: Configure a channel as an ICTD type and connect a probe. If the room temperature is 75 degrees Fahrenheit, then after setting the offset to 10, the expected channel value is 85 degrees Fahrenheit; however, the value reads 80.55 degrees Fahrenheit.

Workaround:

Compensate for the 5/9ths applied offset by multiplying the intended offset first by 9/5, then enter that value into PAC Control or groov Manage.

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 © 2020 Opto 22. All rights reserved.