ProSoft Technology MVI46-MCM - Manual (Page 28)

Ladder Logic MVI46-MCM ♦ SLC Platform
User Manual Modbus Communication Module
Page 28 of 108 ProSoft Technology, Inc.
March 29, 2011
3.1 Module Data
All data related to the MVI46-MCM module is stored in user defined data areas.
The user is responsible for setting up the data areas to match the specific
application for which the module is used. Each data area is discussed in the
following topics.
3.1.1 Backplane Parameters
In this revision of the module, all data to be transferred between the SLC
processor and the module is held in the module's M1 file. This simplifies the
ladder logic. In order to read data in the module, copy the specific data area in
the M1 file into a user defined file. Repeat this operation for each data area.
Remember, the maximum data area that can be copied with the COP instruction
is 128 words. In order to write data to the module, copy the data in the user
defined file to the specific data area in the M1 file. The read and write data
operations should be limited to the M1 words 0 to 4999. The modules status data
can be read from the M1 file starting at register 7200.
Only one parameter is used in this section of the configuration.
The Error Status Pointer parameter defines the location in the module's database
where the error/status data is stored. If the value is set to -1, the data will not be
stored in the user data area. A value between 0 and 4939 will cause the module's
program to store the data at the specified location.
3.1.2 Port Parameters
These parameters define the operation of each of the Modbus ports on the
module. Refer to MVI46-MCM Configuration Data Definition for a definition of
each parameter.