36
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