[Observium] need some help with an alert checker

Hi, I have been able to write some basic checks but I need a little help with this. I want to write a check to alert when my ups’ switch to battery. I think I can do that by checking if the “source of output power” is not normal, but I do not know how to translate that logic into conditions and associations..can someone help?

Thanks

BTW, is there an exchange where people post their checks for others to use?

Tony