MVI56E-MCMR ♦ ControlLogix Platform
Configuring the MVI56E-MCMR Module
Modbus Communication Module with Reduced Data Block
User Manual
ProSoft Technology, Inc.
Page 65 of 223
Read Coil Status 0x (Modbus Function Code 1)
Modbus Function Code 1 reads the Coils addressed at 0001 to 9999 from a
slave device. These are bit values that are read using Modbus Function Code 1,
and can be written to using Function Code 5 or 15. Within a Slave device, this is
an individual bit value. Thus, the Internal Address field must be defined down to
the bit level within your MasterCmd.
The following illustration shows a sample command to read Modbus addresses
0321 to 0480 from Modbus Slave Device Address 1.
Parameter
Description
Enable = 1
The module will send the command every time it goes through the
command list.
Internal Address = 16320
Places the data read from the slave device into the module at
address 16320. Internal Address 16320 of the module memory will be
copied into the tag
MCMR.DATA.R
EAD
D
ATA
[20]
because 16320
represents a bit address within the memory of the MVI56E-MCMR
module (16320 / 16 = register 1020).
Reg Count = 160
Reads 160 consecutive bits from the Slave device.
Node Address = 1
Issues the Modbus command to Modbus Slave Device Address 1.
Modbus Function =1
Issues Modbus Function Code 1 to Read Coils.
MB Address in Device =
320
Function Code 1, MB Address in Device of 320 will read address
0321
Along with a count of 160, this command reads 0321 to 0480.
