34
RS-232 DEMONSTRATION PROGRAM
If an RS-232 scanner is not communicating with your IBM compatible PC, key in
the following BASIC program to test that the communication port and scanner are
working.
This program is for demonstration purposes only. It is only intended to prove that
cabling is correct, the com port is working, and the scanner is working. If the bar
code data displays on the screen while using this program, it only demonstrates
that the hardware interface and scanner are working. At this point, investigate
whether the application software and the scanner configuration match.
If the application does not support RS-232 scanners, a software wedge program
that will take RS-232 data and place it into a keyboard buffer may be needed.
This program tells the PC to ignore RTS-CTS, Data Set Ready (DSR) and Data
Carrier Detect (DCD) signals. If the demonstration program works and yours still
does not, jumper RTS to CTS and Data Terminal Reading (DTR) to DCD and
DSR on the back of your PC.
10 CLS
20 ON ERROR GOTO 100
30 OPEN “COM1:9600,S,7,1,CSO,DSO,CD0,LF” AS#1
35 PRINT “SCAN A FEW BAR CODES”
40 LINE INPUT #1, BARCODE$
50 PRINT BARCODE$
60 K$ = INKEY$: IF K$ = CHR$(27) THEN GOTO 32766
70 GOTO 40
100 PRINT “ERROR NO.”; ERR ;“PRESS ANY KEY TO TERMINATE.”
110 KK$ = INKEY$: IF K$ = “”THEN GOTO 110
32766 CLOSE: SYSTEM
32767 END