I have replaced with four of these controllers to outrageously expensive red Siemens controller block YH36, of (though after 30 years) a control characteristic 0% 60% 100% exhibited. On reflection (and the help of Josef Scholz Reparaturtip) I realized what connections I had to join in order to obtain the Siemens function. It now works even better than I thought before. Top regulator for little money!