PLC is mainly used for data acquisition, control and regulation in the integrated automation system of hydropower station, which plays a pivotal role in the normal operation of the station, and how to realise the data communication between PLC and the host computer is also crucial.3500/22M downloads the generated .HEX file to the fixed address of the chipset through the serial port, so that the kernel can call it, thus completing the development of the secondary driver. The secondary driver development is completed. At this point, the development of 16-channel analogue PLC is basically complete.

3500/22M based on embedded PLC development of multi-channel analogue network node has the following functions: 1, the acquisition of industrial field of multi-channel thermocouple signals, 2, support for Mitsubishi, Delta and many other human-machine interfaces, 3, support for ladder programming (86 instructions), 4, support for CANbus interconnections (multi-machine parallel operation or expansion unit connection) and so on. Here is a brief introduction to the ladder function application of this network node.

The 3500/22M has a temperature conversion function built into the system software, whose function is to convert the AD value corresponding to the thermocouple millivolt signal into a temperature value. It is suitable for any indexed thermocouple input signal, applied to different temperature control occasions, with PID regulation, so that the controlled temperature accuracy can reach ±1℃. The standby PLC can not get some state quantities in the main PLC, such as analogue quantity, scanning quantity, etc.; if the program in the main PLC with sequence flag bit, or need to keep the peripheral equipment relay, once the main and standby switching, the program will not be able to continue to run normally, the peripheral equipment may be out of service.