D12 Expert Series
page
10
Self-diagnostics
D12 Expert sensors provide several self-diagnostic functions. One or more flashing
LEDs on the 7-segment display indicates a trouble condition. In addition, an alarm
output warns of marginal sensing conditions.
The D12 Expert’s 7-segment display indicates four problems:
Display: LED #7 flashes and green ON indicator is ON steadily. (Figure 6.)
Problem: The sensor flashes the #7 LED continuously and energizes the alarm output
when a marginal sensing condition develops during RUN mode. The
sensing area should be checked for any change which might affect the
received light level in either or both sensing conditions (for example, dirt
buildup on the sensing end of a fiber, misalignment of a fiber, or a change
in the target’s physical properties). If no changes can be identified, try
re-teaching the sensor.
Display: LED #7 flashes and green ON indicator is OFF. (Figure 7.)
Problem: Load output is overloaded. Remove power, correct the problem, and
re-apply power. Sensor will come up in RUN mode with the most recent
settings.
Display: LEDs #1 and 7 flash together, 6 times. (Figure 8.)
Problem: This occurs at the end of TEACH mode, when the sensor has received faulty
data. Faulty data may result from an unstable target or from high electrical
noise occurring while TEACH mode is in process. The sensor will return to
RUN mode, with the previous setting. Try re-teaching the sensor.
Display: LEDs #2 and 7 flash together. (Figure 9.)
Problem: These LEDs flash continuously to indicate a sensor component failure.
Return the sensor to the factory for replacement.
Figure 6. LED #7 flashes when a marginal
sensing condition develops.
ON
7
6
5
4
3
2
1
ALM
LO
DO
40 ms
0 ms
Indicator OFF
Indicator ON
Indicator Single-Flashing
Figure 7. LED #7 flashes with the power
indicator OFF; load output is
overloaded.
ON
7
6
5
4
3
2
1
ALM
LO
DO
40 ms
0 ms
Indicator OFF
Indicator ON
Indicator Single-Flashing
Figure 8. LEDs #1 and 7 flash together,
signaling faulty data.
ON
7
6
5
4
3
2
1
ALM
LO
DO
40 ms
0 ms
Indicator OFF
Indicator ON
Indicator Single-Flash 6 Times
Figure 9. LEDs #2 and 7 flash together,
signaling a sensor component
failure.
ON
7
6
5
4
3
2
1
ALM
LO
DO
40 ms
0 ms
Indicator OFF
Indicator ON
Indicator Single-Flashing
