perfect, thanks ralf

but this there a special position in code where to set this?
If i change to 0 after init (prc = Phidget_setHubPort((PhidgetHandle)ch, channelInfo.hubPort))... (PhidgetEncoder_setPositionChangeTrigger(ch, 0)) nothing changes, the interval is stable on 1000ms.

We try to use a dial encoder as device for receiving zoom data from a camera. In a small interval (20ms) we need either a position value or a callback function for this. We modified the encoder sample to reduce the interval setting, but nothing happens. ... PhidgetEncoder_setDataInterval(ch, 20); Ph...