Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual - Manual (Page 74)

Chapter 5
Developing Programs
5-14
In direct-connect mode, the control coprocessor can communicate directly
with a PLC-5 programmable controller using DTL and MSG functions.
Also, in direct-connect mode, you can use BPI functions for backplane
communication with a programmable controller. See page 5-18 for more
information on programs using BPI functions.
ATTENTION: The control coprocessor does not incorporate
hardware memory protection between processes. It is the user’s
responsibility to ensure that programs do not overwrite memory
used by other programs or by the operating system. This could
result in unpredictable system operation.
DirectĆConnect Program Requirements and Flow
C Program Development BASIC Program Development
Start of main program
¬ Function must be included first and once in each program. Note that for BASIC programs, CC_INIT is accessed using AB_BAS(0).
­ Only necessary when using DTL_ functions.
® The multiĆtasking operating system can perform application processes that include combinations of the API functions.
DTL_C_DEFINE ­
DTL_INIT ­
CC_INIT ¬
Start of main program
Write
Application Code ®
DTL_ or MSG_
functions
BPI_ functions
CC_ and TAG_
functions
DTL_ or MSG_
functions
AB_BAS(0) ¬
DTL_INIT ­
DTL_C_DEFINE ­
Write
Application Code ®
BPI_ functions
CC_ and TAG_
functions
Prepare Programs for
DirectĆConnect Mode