ProSoft Technology MVI46-GSC - Manual (Page 53)

Reference MVI46-GSC ♦ SLC Platform
Generic Serial Communication Module
ProSoft Technology, Inc. Page 53 of 78
December 5, 2007
Command Control Blocks
Command control blocks are special blocks used to control the module or
request special data from the module. The current version of the software
supports two command control blocks: warm boot and cold boot.
Warm Boot
This block is sent from the SLC processor to the module when the module is
required to perform a warm-boot (software reset) operation. This block is
commonly sent to the module any time configuration data modifications are
made. This will force the module to read the new configuration information and to
restart. To warm boot the module, place a value of 254 in word 100 of the M0 file.
Cold Boot
This block is sent from the SLC processor to the module when the module is
required to perform the cold boot (hardware reset) operation. This block is sent to
the module when a hardware problem is detected by the ladder logic that
requires a hardware reset. To cold boot the module, place a value of 253 in word
100 of the M0 file.
5.2.2 Data Flow between MVI46-GSC Module and SLC Processor
The following topics describe the flow of data between the two pieces of
hardware (SLC processor and MVI46-GSC module) and other devices attached
to the application ports. Each application port on the module is configured
independently to interface with serial communication devices. The sections below
show the three possible types of communication devices that can be attached to
the application ports: write-only, read-only and read-write.