SICK CLV 421

Chapter 8 Operating Instructions
CLV 42x bar code scanner
8-6 © SICK AG · Division Auto Ident · Germany · All rights reserved 8 009 981/O078/16-08-2004
Troubleshooting
8.5.2 Malfunctions in reading mode: reading pulse errors
Prerequisite The "Device Ready" LED lights up. If not, see Table 8-3, Page 8-5.
Malfunction Possible cause Remedy
1. Pulse mode:
sensor input
(external sensor).
The CLV cannot be pulsed:
– the "Laser On" LED does not light up
– the scan line does not appear
• Incorrect reading pulse source
parameterized on the CLV
• Polarity of switching input inverted
• Sensor not connected or connected to
incorrect switching input
• If sensor supplied by CLV: sensor not
connected to ground potential
• Photoelectric switch not aligned with the
reflector (photoelectric switch/inductive
sensor not dampened)
• In the CLV Setup program: Select the
DEVICE CONFIGURATION tab and click the
READING TRIGGER PARAMETERS button.
READING TRIGGER SOURCE group: sensor
input selected?
• Active high: reading pulse starts when
power applied
• Connect sensor to "Sensor 1" switching
input.
Check sensor wiring (Fig. 5-4, Page 5-8).
Measure output signal on sensor.
• Insert jumper between pin 5 and pin 15
• Align sensor. Check functioning.
2. Pulse mode:
Reflector polling
The CLV cannot be pulsed:
– the "Laser On" LED flickers but does
not light up constantly
– the scan line is very faint
• Incorrect reading distance (polling
reflector)
• Incorrect reflector type used
• Incorrect pulsing sequence (reflector is
not blocked to start the reading interval
on the CLV)
• Check: reading distance of reflector in
specified reading range?
• Check reflector type, Table 4-2,
Page 4-11.
• Check sequence:
Read: 1. Block reflector, 2. Read bar
code, 3. Unblock reflector.
3. Pulse mode:
Serial Interface
The CLV cannot be pulsed:
– the "Laser On" LED does not light up
– the scan line does not appear
• Incorrect reading pulse source
parameterized on the CLV
• The CLV is not receiving any command
string to start the reading interval on the
data interface
• In the CLV Setup program: Select the
DEVICE CONFIGURATION tab and click the
READING TRIGGER PARAMETERS button.
In the READING TRIGGER SOURCE group: is
serial interface selected?
Group SERIAL INTERFACE: is trigger type
correct?
• Check data connection to host.
In the CLV Setup program: Select the
HOST INTERFACE tab.
In DATA FORMAT group: are the correct
interface type (hardware) and data
format selected?
Group: INTERFACE PROTOCOL: are the
correct start and stop characters
selected?
• Use the CLV Setup program to check the
host command strings: Choose
AUXILIARY
I
NTERFACE tab. Choose MONITOR HOST
I
NTERFACE function. See Chapter 6.5.7
Monitor host interface, Page 6-21.
Download temporarily to the CLV.
4. CLV does not respond to an external
signal that ends the reading pulse
(sensor input, reflector polling, serial
interface)
• Incorrect end of reading pulse
parameterized on the CLV
• No sensor signal
• In the CLV Setup program: Check by
choosing the DEVICE CONFIGURATION tab,
click the
READING TRIGGER PARAMETERS
button.
END OF READING INTERVAL group: is
"Generated by Trigger Source"
selected?
• See Malfunction 1, Remedy
Table 8-4: Troubleshooting: reading pulse errors in reading mode