The light lever detector can be used to detect error of angular encoder so as to improve precision of motion control of astronomical telescope. The device needs to achieve high precision of rotation control and automatic detection. According to the functional requirements of the detecting device

the control system of the angle encoder detection device is designed based on the programmable multi-axis motion controller（ PMAC）

hardware platform of the system is built

and the application software of the control system is compiled

and the synchronous between the CCD camera and data acquisition and exposure the encoder is implemented. Experimental results indicate that absolute value of repetitive positioning error of the turntable is less than 4″

which meet the requirements of the encoder detection system.