ProSoft Technology MVI56E-MCMR - Manual (Page 71)

MVI56E-MCMR ♦ ControlLogix Platform Configuring the MVI56E-MCMR Module
Modbus Communication Module with Reduced Data Block User Manual
ProSoft Technology, Inc. Page 71 of 225
May 13, 2014
Write Multiple Coils 0xxx (Modbus Function Code 15)
Use this function code to write multiple Coils in the 0x address range. This
function code sets multiple Coils within a slave device using the same Modbus
command. Not all devices support this function code. Refer to your slave device
documentation before implementing this function code.
This function code will also support the Enable code of 2, to write the data to the
slave device only when the data associated within the Internal Address field of
the module has changed. The Internal Address is once again defined down to the
bit level as a Function Code 15 is a bit level Modbus function.
The following illustration shows a sample command to write Modbus addresses
0001 to 0016 of Modbus Slave Device Address 1.
Parameter Description
Enable = 2 The module will send the command to the slave device only when the
data associated within the Internal Address of the MVI56E-MCMR
module memory has changed.
Internal Address = 320 Writes the data in bit 320 of the module memory to the slave device.
Based on the B
ACKPLANE C ONFIGURATION setting, this would be the
data in MCMR.DATA.W RITE D ATA [20].0 to [20].15 in the ladder logic.
Reg Count = 16 Writes 16 consecutive bits to the slave device.
Node Address = 1 Issues the Modbus command to Modbus Slave Device Address 1.
Modbus Function =15 Issues Modbus Function Code 15 to write multiple coils.
MB Address in Device = 0 Function Code 15, MB Address in Device of 0 will read address 0001
Along with a count of 16, this command writes to 0001 to 0016.