This example demonstrates how you might configure a Simple Modbus Analog point to represent Input Register data from a Modbus PLC. The analog point is to present the data in UINT format in ClearSCADA.
Example:
Within ClearSCADA, an analog Input point is to contain data from the second Word in the Input Register range 300003 to 300006. The point is to present the data in unsigned 16-bit format.
The configuration of the Simple Modbus scanner with which the point is associated is detailed in an earlier example (see A Simple Modbus Scanner Configured to Scan Four Input Registers). The addressing at the Modbus PLC starts at 1.
Within ClearSCADA, the Simple Modbus Analog Input Point is configured as follows:
Word Offset:1
(As the point is to retrieve data from the second Word in the scanned address range (the first Word being 0).)
Data Type:UINT
(UINT specifies that the data is to be presented in unsigned 16-bit format.)
The Source attribute for the point confirms that the point is to contain data from the second Word in the Input Register range 300003 to 300006:
MODBUS/TCP-8 502:Device 5, Input Registers - AG 3:00004 (UINT)
(3:00004 indicates the Modbus address 300004, which contains Input Registers in this particular PLC. The point is to present the data in unsigned 16-bit format.)