Mvi Backplane Api Architecture - Rockwell Automation Allen-Bradley ControlLogix 1756-MVI Programming Reference Manual

3-2 MVI Backplane API
MVI Backplane API
Architecture
Publication 1756-RM004B-EN-P - October 2000
The MVI API is composed of three parts:
• a memory resident driver, MVI56DD.EXE (called the MVI driver)
• a statically-linked library (called the MVI library)
• a header file
Applications using the MVI backplane API must be linked with the MVI
library. The header file must be included. In addition, the MVI driver
must be loaded before an MVI API application can be executed. This
architecture makes it possible to design MVI applications that can be
run on any of the Rockwell or third party MVI modules without
modification or recompilation.
The MVI driver calls the CIP API (and its associated driver,
MVI56BP.EXE) to register the assembly object. Several instances of the
assembly object support the direct I/O and messaging data transfer
functions provided by the MVI API.
Both the backplane device driver (MVI56BP.EXE) and the MVI
backplane API driver (MVI56DD.EXE) must be loaded before executing
an application that uses the MVI API. MVI56BP.EXE must be loaded
prior to MVI56DD.EXE. These files may be loaded from the
CONFIG.SYS or AUTOEXEC.BAT files.