ProSoft Technology MVI56E-MCMR - Manual (Page 88)

Configuring the MVI56E-MCMR Module MVI56E-MCMR ♦ ControlLogix Platform
User Manual Modbus Communication Module with Reduced Data Block
Page 88 of 225 ProSoft Technology, Inc.
May 13, 2014
To copy data from the MVI56E-MCMR module to a floating-point tag within the
ControlLogix processor
1 Configure a tag within the ControlLogix processor as shown.
2 Then configure the COP statement to move data from the
MCMR.DATA.R EAD D ATA array, and over to the new tag
MCM_R EAD _F LOATS tag as shown here.
Once again, the COP statement will take as many of the Source elements
required to fill the Dest tag for the length specified. Therefore, the COP statement
will take MCMR.DATA.R
EAD D ATA [0] TO [19] to fill the MCM_R EAD _F LOATS [0] TO
[9].
Enron/Daniel Float Configuration
Sometimes it is necessary for the module to emulate Enron or Daniel floating-
point addressing.
Copying the data to the MCMR.DATA.W RITE D ATA array and from the
MCMR.DATA.R EAD D ATA array is the same as described in the section above.
The main difference is the addressing of the module.
For example, an Enron Float device is required to access address 47001 for
floating-point data, and each Modbus register would emulate a single float value
(does not require 2 Modbus addresses for 1 float value).
A Master device requiring this type of addressing, would require that for every
count of 1, the MVI56E-MCMR module responds to the request message with 4
bytes (one 32-bit REAL) value.
To emulate this addressing, the module has the parameters F LOAT F LAG , F LOAT
S TART , and F LOAT O FFSET .
Value Description
Float Flag Tells the module to use the Float Start and Float Offset parameters
listed below
Float Start Determines what starting address on the Modbus network to treat as
floating-point data. A value of 7000 will signal the module that
address 47001 on the Modbus network is the starting location for
Modbus floating-point data. Every address will occupy 2 registers
within the module's database.
Float Offset Determines the address within the module to which to associate the
data from the Float Start section.