Rice Lake 880 Performance Series Panel Mount Indicator/Controller - Modbus TCP Interface Option Installation and Programming Manual - Manual (Page 16)

12 Modbus Interface Installation and Programming Manual
4.0 Commands
Commands are used by the master device to send and receive data from the interface
as integer or floating-point data. The master sends eight bytes in the output format
(used to write commands to the indicator) and reads eight bytes in the input format
(used to read data from the indicator).
Decimal Point Handling
Integer commands return no decimal point information to the master. For example, a
value of 750.1 displayed on the indicator is returned to the master as 7501. Floating
point commands support decimal point information with no special handling.
4.1 Output Data Format
To perform a command, the master uses the output command format to send four 16-
bit words to the interface. These four words contain the command and any parameters
necessary to execute it. The output command format is shown in Table 4-1.
See Section 4.1.1 for BYTE swapping parameters.
The contents of each output command format word are described in Table 4-2.
Command number
The number representing the indicator command is sent in the first word. Table 4-2
lists the commands that can be specified for indicators. Some commands may not be
available on all indicators.
A lockout feature that looks for any change in the output format data is
incorporated into the indicator receive mechanism to prevent inundation
by the same command (affected commands noted in Table 4-1).
Repeated commands must be separated by any other valid command/
parameter/value combination.
Word Register Description
Word 1 40005 Command number
Word 2 40006 Parameter
Word 3 40007 Value (MSW)
Word 4 40008 Value (LSW)
All values are write type only.
Table 4-1. Output Data Format
Note
Note