This has got me stumped. I was told by the previous owner this programer was to control school bells . I don’t believe this is correct. It gives a . 3 minute and also a 
30 seconds output duration every 40 mins . Having said that it’s been modified to also give a 3 minute duration output every 20 minutes. It’s designed to to be driven from a standard C7 master clock. I’m still trying to to find more information Andy