ProSoft Technology MVI94-MCM-MHI - Manual (Page 33)

MVI94-MCM ♦ Flex I/O Platform Configuration
Serial Communications Modbus Communication Module User Manual
ProSoft Technology, Inc. Page 33 of 109
March 29, 2011
To copy data from the MVI94-MCM module to a floating-point tag within the FLEX
processor
1 Configure a tag within the FLEX processor as shown.
2 Then configure the COP statement to move data from the
MCM.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 MCM.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 MCM.DATA.W
RITE D ATA
array and from the
MCM.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 MVI94-MCM module responds to the request message with 4
bytes (one 32-bit REAL) value.
To emulate this addressing, the module has the parameters
MCM.CONFIG.P
ORT X.F LOAT F LAG , F LOAT S TART ,
and F
LOAT O FFSET .
Value Description
FloatFlag Tells the module to use the FloatStart and FloatOffset parameters
listed below
FloatStart 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 modules database
FloatOffset Determines the address within the module to which to associate
the data from the FloatStart section.
Here is a sample configuration for the module.