After repeated read the entire booklet was understandable in English. The switching output has unfortunately not potential-free contact but brings in when operated 12V at the output. I have therefore installed a 12V relay (3.50) between the coder and my garage door control. Now works properly.
Assignment of contact file:
DC + 12V: Power supply 12V PLUS GND: power supply 12V MINUS COM: switching output 12V MINUS Push: Switching output 12V Plus