Call 81 - User Memory Module Check And Description - Rockwell Automation Allen-Bradley SLC 500 BASIC Reference Manual

CALL 81 – User Memory
Module Check and
Description
Example: (For saving 2 variables)
>PRINT MTOP
24575
>PRINT MTOP-12
24563
>PUSH 24563:REM NEW MTOP ADDRESS
>CALL 77
>1 REM EXAMPLE PROGRAM
>10 K = 678*PI
>20 L = 520
>30 PUSH K
>40 ST@ 24575 : REM STORE K IN PROTECTED AREA
>50 PUSH L
>60 ST@ 24569 : REM STORE L IN PROTECTED AREA
>70 REM TO RETRIEVE PROTECTED VARIABLES
>80 LD@ 24575 : REM REMOVE K FROM PROTECTED AREA
>90 POP K
>100 LD@ 24569 : REM REMOVE L FROM PROTECTED AREA
>110 POP L
>120 REM USE LD@ AFTER POWER LOSS AND BATTERY BACK-UP IS USED
Purpose
Use CALL 81 to check the user memory module before burning a program into the
memory module. This routine:
• determines the number of memory module programs
• determines the number of bytes left in the memory module
• determines the number of bytes in the RAM program
• prints a message indicating if enough space is available in the memory module
for the RAM program
• checks memory module checksum if program is found
• prints a caution message is checksum fails
CALL 81 cannot detect a defective memory module.
IMPORTANT
No PUSHes or POPs are needed.
Syntax
CALL 81
Command Line CALLs 5-3
Publication 1746-RM001A-US-P