I have the same issue, and pushing the white illuminated button didn't fix the issue. instead, whenever I press the button the 20200 limit switch opened by SC is triggered.
Thanks for your quick response!
This small battery is a "CRXXXX" button type.
It is located on the PCB of DSQC 639 (or previous reference) computer unit. In a standard controller, you'll find this box on the roof of the controller.
If maybe you have a compact controller, it's the same location, but it won't be a DSQC 639 but another reference. In any case, it's inside the computer unit (the box where you insert Compact flash if that helps )
You can change it by yourself, but you'll lose the date and time parameters. That will lead to show a false "maitenance counters" and so on, when you look at that is the SIS datas.
Just reply here if you need more information
if I understood correctly, the only concern about changing the CMOS battery is losing date and time parameters, that means I don't have to worry about anything else correct?
Additionally, how would I resolve the date and time parameters after battery replacement?
Appreciate your time!
Would you be able to share the IFWC documents? I'm basically stuck in the same place. thank you