Communication port 1 is RS232 serial port, and communication port 2 and output ports A and B are RS485 serial ports. Only one of two RS485 can be used.

Solution to solve the problem that the port of Xinjie PLC is occupied by external programs: If more than two Xinjie softwares are opened. At the same time, one is to use serial communication. Another is that the serial port is occupied. Just close the window that occupies the serial port.

The Com at the input end is connected differently according to different signal input types. If the two input signals are the same, short them.