Configuration as a Modbus Master
MVI56-MCM
♦
ControlLogix Platform
Modbus Communication Module
ProSoft Technology, Inc.
Page 43 of 159
July 24, 2008
The length of this COP statement must now be 14. This will COP as many of the
MCM_Float_Data values required to occupy the MCM.Data.WriteData array for a
length of 14. This will take 7 registers, MCM_Float_Data[0]-[6], and place that
data into MCM.DATA.WriteData[0]-[13].
The command to write all 7 floats (14 Modbus addresses) must be configured as
follows.
The above command will take the data from MCM.DATA.WriteData[0]-[13] and
write this information to the slave device node #1 addresses 40261 to 40274.
4.4.4 Read Floats with Single Modbus Register Address
(Enron/Daniel Float)
Some Modbus slave devices will utilize one Modbus address to store 32 bits of
data. This is typically referred to as Enron or Daniel Floating Point.
A device that utilizes this addressing method may have the following Modbus
Memory Map.
Address Data
Type
Parameter
47001
32 bit REAL
Demand
47002
32 bit REAL
Reactive Power
47003
32 bit REAL
Apparent Power
47004
32 bit REAL
Power Factor
47005
32 bit REAL
Voltage: Line to Line
47006
32 bit REAL
Voltage: Line to Neutral
47007
32 bit REAL
Current
This type of device uses one Modbus address per floating point register. To read
these values from the slave device, the following command can be setup within
the module.
