Configuring the MVI56E-MCMR Module
MVI56E-MCMR ♦ ControlLogix Platform
User Manual
Modbus Communication Module with Reduced Data Block
Page 62 of 223
ProSoft Technology, Inc.
If our device listed above shows its addressing as follows:
Then: To read "Switch_Input_Status", you would use Function Code 4 and
use a MB Address in Device of 512.
2.3.6 Master Command Examples
Read Holding Registers 4x (Modbus Function Code 3)
The 4x Holding Registers are used for storing analog values such as pressure,
temperature, current, program counters, timer accumulators and presets, and so
on. Holding Registers store values in 16-bit memory registers. These 16-bit
values can be interpreted in different ways that allow Holding Registers to hold
many different data types, such as 8-bit, 16-bit, 32-bit, or 64-bit signed or
unsigned integers, as well as 32-bit or 64-bit floating-point data (page 71) and
other data types.
The following illustration shows the correct parameter values to create a
command to read Modbus addresses 40001 to 40010 from Modbus Slave Device
Address 1.
