ProSoft Technology MVI56E-MCMR - Manual (Page 72)

Configuring the MVI56E-MCMR Module MVI56E-MCMR ♦ ControlLogix Platform
User Manual Modbus Communication Module with Reduced Data Block
Page 72 of 225 ProSoft Technology, Inc.
May 13, 2014
Preset (Write) Single Register 4x (Modbus Function Code 6)
Used to write to Modbus Holding Registers 4x, this function code will write a
single register to the slave device. The Enable code can be set to a value of 1 for
a continuous write, or a value of 2 to write the data to the slave device only when
the data associated with the Internal Address field has changed.
The following illustration shows a sample command to write Modbus addresses
41041 of 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 = 5 Writes the data from address 5 of the module memory to the slave
device. Based on the B
ACKPLANE C ONFIGURATION , this will take the
data from MCMR.DATA.W RITE D ATA [5] and write that information out
to the slave device.
Reg Count = 1 Writes 1 register (16-bit) to the slave device.
Node Address = 1 Issues the Modbus command to Modbus Slave Device Address 1.
Modbus Function =2 Issues Modbus Function Code 6 to write a single register.
MB Address in Device =
1040 Function Code 6, MB Address in Device of 1040 will write to address
41041 of the Modbus slave device.