ProSoft Technology MVI56-AFC - Manual (Page 81)

MVI56-AFC ♦ ControlLogix Platform Modbus Communication
Liquid and Gas Flow Computer User Manual
ProSoft Technology, Inc. Page 81 of 316
February 25, 2011
6.3.1 Example
The following table shows how the data types are implemented if a write function
is selected and the item count is configured with a value of 10 (decimal):
Data Type Register
Type Modbus
Function Number of
Coils Number of
Bytes Number of
Registers Number of words
(16-bits)
transferred
Bit Coil 15 10 2 - 1
Word Holding 16 - 20 10 10
Long Holding 16 - 40 20 20
Long Remote Holding 16 - 40 10 20
Note: The number of coils, bytes, and registers are part of the Modbus request (functions 15 and
16) according to the Modbus specification.
The following table shows how the data types are implemented if a read function
is selected and the item count is configured with a value of 10 (decimal):
Data Type Register Type Modbus Function Number of Registers
Bit Coil 1 10
Bit Input 2 10
Word Holding 3 10
Word Input 4 10
Long Holding 3 20
Long Input 4 20
Long Remote Holding 3 10
Long Remote Input 4 10
Note: The number of registers is part of the Modbus request according to the Modbus
specification.
Refer to the ladder logic section for your module for more information about the
Modbus Master block.