A-6.2 Program Logic And Overhead - Emerson PACSystems RX3i User Manual

PACSystems™ RX3i and RSTi-EP CPU Reference Manual
GFK-2222AK
▪
▪
A-6.2 Program Logic and Overhead
The data area for C (.gefelf) blocks is considered part of the user program and counts
against the user program size. Additional space is required for information internal to the
CPU that is used for execution of the C block.
The program block is based on overhead for the block itself plus the logic and register
data being used (that is, %L).
Note: The program stack of the LD is not counted against the CPU's memory size.
Note: If your application needs more space for LD logic, consider changing some %P or %L
references to %R, %W, %AI, or %AQ. Such changes require a recompilation of the program
block and a STOP Mode Store to the CPU.
Serial I/O, SNP & RTU Protocols
You can add, change, or delete %L and/or %P variables in your application and RUN
Mode Store the application if these variables fit in the size of the last-stored %L/%P
tables (where the size includes the previous buffer space), or if going from a zero to
non-zero size.
The size of the %L/%P tables is always recalculated for STOP Mode Stores.
Appendix A
October 2019
223