Using a Serial Board
- Last UpdatedJul 18, 2023
- 2 minute read
The communications port on the computer is not designed for high-speed communications and reduces system performance. Instead, install a high-speed serial board. High-speed serial boards have several ports (usually 4, 8, or 16) to let you connect several I/O devices to your Plant SCADA system.
You can use identical I/O devices or I/O devices supplied by different manufacturers; Plant SCADA supports many popular I/O devices. You can connect any number of I/O devices; the only limitation is the size of your computer. High-speed serial boards are available for RS-232, RS-422, or RS-485 communication.
If you have several I/O devices from the same manufacturer and these I/O devices support multi-drop communication, you can connect them to an RS-422 or RS-485 high-speed serial board installed in your computer. (The RS-232 standard does not support multi-drop communication.)
Not every high-speed serial board supports RS-422. You can use an RS-232/RS-422 or RS-232/RS-485 converter to achieve the same arrangement.
Note: Using a converter can introduce handshaking/timing considerations.
To set up Plant SCADA to use a serial board:
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Install the board in your computer and set it up under Windows as per the accompanying instructions. Use the latest driver from the board manufacturer.
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Check that the boards configuration has COMx as the Type, and the Address set to 0. The I/O Port, Interrupt, and Special Opt can be left blank.
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Enter the Port Number in the Ports configuration. The COM port number is usually greater than 2 and set in the Ports section of the Control Panel. Use the Special Options field to modify the behavior of the COMx driver. (See COMx Driver Special Options Reference for more information).
Note:
• If using your computer's COM port, you don't need to install additional software.
• You only need to define the COMx board once. You can then add several ports that use the same Plant SCADA board. For example, a COM port and two serial boards could be defined as one COMx board in Plant SCADA, with multiple ports.