Using CitectSCADA > Communicating with I/O Devices > Setting Up Communications > Ports Properties

Ports Properties

The properties of a port depend on the type of board installed in the I/O Server, and on the I/O Device connected to the port. Ports have the following properties:

Port Name

A name for the port connected to your I/O Device(s). 31 characters maximum. Each port needs to have a unique name (i.e. you cannot assign the same Port Name to two ports in your system). You can use any name, for example: Board1_Port1

If you have more than one board in your computer, you can use the port name to identify the board, for example: Board2_Port1

Port Number

The port number that the I/O Device is connected to. 4 characters maximum. Do not assign the same Port Number to two ports on a board, unless connecting to a dial-up remote I/O Device via a modem (see the note below). Ports on different boards can be assigned the same number.

If you are using your computer's COM port enter the port number here - the port number is defined in the Ports section of the Windows Control Panel.

Note: If you are connecting to a dial-up remote I/O Device (via a modem), you need to define a unique port name on the I/O Server for each dial-up remote I/O Device, and the port number needs to be -1 for each.

Board Name

The name you used for the board. 16 characters maximum. This is necessary to link the port to the board. For example Server1_Board1

Baud Rate

The baud rate of the communication channel (between the CitectSCADA I/O Server and the I/O Device). 16 characters maximum.

Note: The I/O Device hardware and serial board may support other baud rates. If you do choose an alternative baud rate, verify that both the I/O Device and serial board support the new baud rate.

Data Bits

The number of data bits used in data transmission. You need to set your I/O Device to the same value or a communication link cannot be established.

Stop Bits

The number of stop bits used to signify the completion of the communication. You need to set your I/O Device to the same value.


The data parity used in data transmission.

Special Opt

Any special options supported by the port. 32 characters maximum. Please check the Hardware Setup Help Topic for your specific I/O Device to see if specific options are necessary.


Any useful comment. 48 characters maximum.