Rockwell Automation 1746-BAS BASIC LANGUAGE - Manual (Page 132)

Publication 1746-RM001A-US-P
11-2 Status Functions
CALL 36 – Get Number of
Characters in PRT2
Buffers Purpose
Use CALL 36 to retrieve the number of characters in the chosen buffer of port
PRT2.
You must PUSH the buffer that you want examined:
PUSH 1 for the input buffer
PUSH 0 for the output buffer
One POP is required to get the number of characters.
Syntax
PUSH [buffer selection]
CALL 36
POP [number of characters]
Example
>1 REM EXAMPLE PROGRAM
>10 PUSH 0 : REM EXAMINES THE OUTPUT BUFFER
>20 CALL 36
>30 POP X : REM GET THE NUMBER OF CHARACTERS
>40 PRINT “NUMBER OF CHARACTERS IN OUTPUT BUFFER IS”,X
>50 END
READY
>RUN
NUMBER OF CHARACTERS IN OUTPUT BUFFER IS 0
READY
>