58
TROUBLESHOOTING
RS232 DEMONSTRATION PROGRAM
If an RS232 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 RS232 scanners,
a software wedge program that will take RS232 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,CS0,DS0,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$(27) THEN GOTO 32766
70 GOTO 40
100 PRINT “ERROR NO.”; ERR; “ PRESS ANY KEY TO TERMINATE. ”
110 K$ = INKEY$: IF K$ = “” THEN GOTO 110
32766 CLOSE: SYSTEM
32767 END