When using COM1, there are two types: round port and port.
- COM1 (round port 8 pins): Serial port parameters (baud rate, data bit, check bit, stop bit, etc.) are fixed and cannot be modified.
- COM1 (Port): The baud rate can be modified in serial port parameters (baud rate, data bit, check digit, stop bit, etc.), and other parameters can not be modified. Baud rate is set by system special address D8110.
When using COM2, the baud rate of the PLC and other serial port parameters can be set by writing a value to the special address D8120 by the program.