ProSoft Technology MVI71-GSC - Manual (Page 48)

MVI71-GSC ♦ PLC Platform Reference
Generic Serial Communication Module
Page 48 of 82 ProSoft Technology, Inc.
January 31, 2008
PLC Processor Not in Run
Whenever the module detects that the processor has gone out of the Run mode
(that is, Fault or PGM), the application ports can be shut down as prescribed in
the user configuration. When the processor is returned to a running state, the
module will resume communications on the serial networks.
5.1.6 Backplane Data Transfer
The MVI71-GSC module communicates directly over the PLC backplane. Data
travels between the module and the PLC processor across the backplane using
the block transfer interface (BTR/BTW) or the side-connect interface (direct
connection to user files in the PLC processor).
Data received on the application ports is transferred from the module to
processor across the backplane. This data is processed by the ladder logic in the
PLC processor. The data window through which the data is passed between the
module and the processor is dependent on the interface utilized. For the
BTR/BTW interface, up to 50 bytes of data is transferred for each port in each
data transfer. When using the side-connect interface, up to 400 bytes can be
transferred between the processor and the module in each data movement
operation.
When the BTR/BTW interface is used, each data block moved between the
module and processor contains a field for a block sequence number. The codes
contained in this field have the following definitions:
Block ID Description
9999 Cold boot module
9998 Warm boot module
9000 Configure module
0 to 127 Normal data blocks for read and write
Normal data movement is accomplished using block codes of 0 to 127. The other
block identification codes request the configuration for the module from the
processor or to control the module from the ladder logic.