Jacek,

I tried to find the part number on the Siemens website, but found too many company divisions to search, so I don't have advice specific to the subject encoder.

I've seen a few devices from other manufacturers that output Gray code, 10 bits all the way up to 20 bits and use a differential driver (like RS485) on each output bit to reduce noise. Devices I've seen are available with parallel output for position and an incremental output for speed. A few devices have serial output of position for low speed operation.

If you have a parallel output device, try looking at each output on the 'scope while rotating the shaft. Similarly, if you have a serial device, try recording the received bit pattern (via a serial port program) as the shaft is rotated, then examine the recording for the expected bit pattern.

Good Luck,

Bruce