With some brands of I/O Devices you can install a proprietary interface board in your computer, or intermediary software. This PLC interface board/software is supplied by the PLC manufacturer; you can connect it to a single PLC or a PLC network.
Note: With some PLCs, a high-speed serial board provides better performance than a PLC interface board when the system is connected to more than one PLC.
You can mix both PLC interface boards and high-speed serial boards in a single computer. You can, for example, connect a PLC network to a PLC interface board, and individual I/O Devices to a high-speed serial board.
There are many possible hardware arrangements for a CitectSCADA application. CitectSCADA is a flexible system and imposes few restraints on the type (or manufacturer) of I/O Devices that you can use, or on the way you connect them to the computer.
To set up CitectSCADA to use a proprietary board/software:
If you are using a proprietary board/software (that is, supplied by the PLC manufacturer):