Metrologic Instruments MS6720 - Manual (Page 33)

27
T ROUBLESHOOTING G UIDE (C ONTINUED )
RS-232 only
SYMPTOMS POSSIBLE CAUSE(S) SOLUTION
Power-up OK
Scans OK
Does not
communicate
properly to the host
Com port at the host not
working or not configured
properly
Cable not connected to
the proper com port
Com port not operating
properly
Check to make sure the baud
rate and parity of the scanner
and the communication port
match and the program is
looking for “RS-232" data.
NOTE: Metrologic’s default of 7 data bits, space parity is usually what is expected
when an IBM compatible type PC is configured for 8 data bits, no parity.
SYMPTOMS SOLUTION
Host receiving data but data does
not look correct Check that the scanner and host are
configured for the same interface format
Characters are being dropped
Add some intercharacter delay to the
transmitted output. This can be
programmed into the scanner through
ScanSelect
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,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$: IF K$ = “” THAN GOTO 110
32766 CLOSE: SYSTEM
32767 END