recording/trending/logging dry-contacts

[comfortmaster1]

Looking for a cheap way to have a historical record of when a unit starts and stops. I'm thinking someone probally have an idea for a home-made one. Maybe involving a time clock and a current sensor/relay.

[cxagent]

I've been using the HOBO motor on/off data loggers for this. http://www.1800loggers.com/solutions/products/loggers/_loggerviewer.php5?pid=17 They work well and record the time to the second. I think the loggers are about $80 each but you will also have to buy software & cable if you don't have them. http://www.1800loggers.com/solutions/products/software/index.php5?programid=3 I think there is a cheaper software package (not Pro version) but I don't know anything about it.

[codewriter]

I concur, the HOBO (despite its name) is a great product and very effective.