This issue affects only I/O coprocessors in rack-mounted SNAP PAC controllers and brains manufactured during the following time periods:
- SNAP-PAC-R1, -R1-FM, and -R1-W: 06/16 through 03/17.
- SNAP-PAC-R1-B: All codes through 03/17.
- SNAP-PAC-R2, -R2-FM, and -R2-W: 02/16 through 03/17.
- SNAP-PAC-EB2, -EB2-FM, and EB2-W: 08/16 through 03/17.
This issue does not affect SNAP-PAC-EB1, -SB1, or -SB2 series brains.
To determine if your device has an I/O coprocessor, see form RM_IO_COPR_FW, the SNAP PAC I/O Coprocessor Firmware Readme.
If the value of an analog output point changes, after a few minutes, the value may then reset to the module's "low scale" or zero-equivalent value.
- Unipolar modules (like SNAP-AOV-5, all of the SNAP-AOA series, AOV-25, AOD-29 series, and some points on -AOVA-8) may reset to their low scale value.
- Modules with bipolar points (like SNAP-AOV-7, -27, and some points on -AOVA-8) may reset to the value associated with zero counts. (For example, on a -10 to +10 VDC output, the point may reset to 0 VDC).
You can see this behavior by using PAC Manager (Tools > Inspect >Analog Bank button), and periodically clicking the Refresh button to see if a change has happened.
Also, the counts for Module n- Times Discovered and for Arcnet Reconfigs may slowly increase over time (when they shouldn't). This behavior is also visible using PAC Manager (Tools > Inspect > Status Read button, and clicking Refresh to watch for changes).
Opto 22 has resolved this issue.