Doing Zero calibration of controller again. Calibration method: open the control cabinet door, the upper left corner of the red dial switch to the corresponding channel, the blue is the function of choice, set aside to ON that is selected. Regulation of all appropriated OFF, the corresponding channel is allocated to ON, a blue dial the last one to ON ("ZERO"), press the mute button, the blue dial toggle the last one to OFF, and then press the mute button. Zero calibration complete. Red dial back to the factory settings.

Check detector wiring, or measure the voltage of the detector between "24V" "GND"  is 24V. Or whether the current of the detector  between the “I+”, and “GND” between  is 4mA.

Detector output abnormal, the proposed detector. Suggested to check the detector.