Rockwell Automation 1771-DB Basic Module User Manual - Series A - Manual (Page 130)

Operating Functions
Chapter 5
5–93
The Active LED is on constantly during program execution or command
mode. When you issue a CALL 79 the Active LED remains on while a
program executes and blinks every second when the module is in the
command mode. Issue CALL 79 again to cancel the blinking LED.
CALL 80 checks the module’s battery condition. If a 0 is POPed after a
CALL 80, battery is okay. If a 1 is POPed a low battery condition exists.
Example:
u10 CALL
80
u20 POP
C
u30 IF
C
tu0 THEN PRINT “BATTERY LOW”
u40 END
Use CALL 81 before burning a program into PROM memory. This routine:
determines the number of PROM programs.
determines the number of bytes left in PROM.
determines the number of bytes in the RAM program.
prints a message telling if enough space is available in PROM for the
RAM program.
checks PROM validity if no program is found.
prints a good or bad PROM message. A bad PROM message with an
address of 00xx indicates an incomplete program.
cannot detect a defective PROM.
No PUSHes or POPs are needed.
5.12.2
Blink the Active LED by
Default – CALL 79
5.12.3
Check Battery Condition –
CALL 80
5.12.4
User PROM Check and
Description – CALL 81