ProSoft Technology MVI46-MCM - Manual (Page 62)

Reference MVI46-MCM ♦ SLC Platform
User Manual Modbus Communication Module
Page 62 of 108 ProSoft Technology, Inc.
March 29, 2011
SLC Processor Not in Run
Whenever the module detects that the processor has gone out of the Run mode
(that is, Fault or PGM), the Modbus ports will be shut down. When the processor
is returned to a running state, the module will resume communications on the
network. No backplane data transfers occur when the processor is not in run
mode.
Backplane Data Transfer
The MVI46-MCM module communicates directly over the SLC backplane. All
data for the module is contained in the module's M1 file. Data is moved between
the module and the SLC processor across the backplane using the module's M-
files. The SLC scan rate and the communication load on the module determine
the update frequency of the M-files. The COP instruction can be used to move
data between user data files and the module's M1 file.
The following illustration shows the data transfer method used to move data
between the SLC processor, the MVI46-MCM module and the MCM network.