Serial Port Properties: Serial Port Connection

If you select the serial port connection method, you need to define the following:

Baud Rate Enter the baud rate for communications. Click the drop-down list to the right of the input field and select a rate from the list.
Data Bits Select the number of data bits per word to be used for communications.
Parity Select the parity to be used for communications.
Stop Bits Select the number of stop bits to be used for communications
Flow Control Select the type of flow control to be used for communications. If you change the Flow Control type, you must reboot the PC for the changes to take affect.

Remember that you must configure the same baud rate, data bits, parity, stop bits and flow control for all PLCs using the serial port.