ProSoft Technology MVI56-BAS - Manual (Page 37)

MVI56-BAS ♦ ControlLogix Platform BASIC Programming
BASIC Module (DB/BAS Compatible) User Manual
ProSoft Technology, Inc. Page 37 of 234
December 13, 2011
3.4 ControlLogix Processor Interrupt
The MVI56-BAS allows the ControlLogix to interrupt the current BASIC program
using CALL 20 (Enable Processor Interrupt). When word 0 bit 15 in the output
image (Local:x:O:Data[0].15) toggles from OFF to ON, the program jumps to the
line number specified by the CALL 20 parameter.
Use the
RETI
command in order to return to the point the program was before
being interrupted.
The following BASIC program shows how to use CALL 20:
10 PUSH 50: REM JUMPS TO LINE NUMBER 50
20 CALL 20
30 GOTO 30
35 PRINT "LINE 35"
40 PRINT "LINE 40"
50 PRINT "LINE 50"
60 PRINT "LINE 60"
70 RETI
80 END
While the program is running, the following ladder logic is executed:
The result is:
LINE 50
LINE 60
To disable the processor interrupt, use CALL 21 (Disable Processor Interrupt).
This routine has no arguments and does not return any value.
Refer to BASIC CALLs Syntax (page 105) for more information about CALLs 20
and 21.