characteristics：
1.tracing edge ,centring and tracing wire.
2.support photoelectric sensor ultrasonic sensor and shadeguide sensor.
3.PI caculation is adopted ,it has accuracy ,quick response time
4.fast speed, 400 microsecond response time
5.drive speed 40mm/s，thrust>=250Kg，maximun thrust weight 2.5 ton
6.analog signal 16 bit AD sampling ，sampling speed 700000/s
7.FIR digtal filter ，return different filter，anti-interference
8.DC servo motor pushes the roll thread
9.simple chinese/traditional chinese /English can be chosen
10.Modbus embeded in PLC
