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The auto adjust setting is recorded in non-volatile memory and is retained through power cycling of the
LH200.
B
- Bias
Displays and opens the bias value for change. If the displayed value is to be retained, simply press ENTER
to accept the current value. Otherwise, enter the new value then press ENTER. Acceptable range is 1
through 100. Default is 30. This command cannot be entered when a machine is running (LH200 is receiving
a periodic ENABLE signal).
This value determines the size of the dead-band from complete darkness to a measurable signal. Increasing
this value decreases the sensitivity of the LH200. The smaller the bias value, the more likely extraneous
noise may trigger a leak response from the LH200. In most instances, adjusting the Bias is not necessary.
NOTE: The bias value should only be changed when the sensor is in complete darkness since a change to
the bias value automatically initiates a re-calibration of the LH200. Calibration may also be initiated through
the "C" command.
The bias value is recorded in non-volatile memory and is retained through power cycling of the LH200.
C
– Cal Offset
Initiates calibration of the internal offset voltage required to maintain the bias as specified through the "B"
value. The gain setting does not affect this operation. NOTE: For meaningful calibration, the face of the
LH200 must be in complete darkness. This command cannot be entered when a machine is running (LH200
is receiving a periodic ENABLE signal).
D
– Dark Limit
Displays and opens the dark limit value for change. If the displayed value is to be retained, simply press
ENTER. Otherwise, enter the new value then press ENTER. Acceptable range is from 1 to 4000. The
default is 30. This parameter determines how much light leakage is allowed after the test cycle has begun
and before the flash has been triggered. If the average of the dark readings during a test cycle exceeds the
dark limit, the report LED is set to amber and the RESULT output is turned off (reject state).
The dark limit is recorded in non-volatile memory and is retained through power cycling of the LH200.
F
- Free-Run Mode
The LH200 is set to free-run mode by entry of the "F" command through the serial port. Free-run mode
cannot be entered if the machine is running (LH200 is receiving a periodic ENABLE signal). The operation
of the LH200 in free-run mode is as follows:
1. The ENABLE signal is ignored.
2. A cycle begins immediately after entry of the "F" command. The results of the test are reported on the
RESULT output, on the result LED, and the serial output.
3. The cycle repeats every 100 milliseconds until a character comes in from the serial port. Any character
from the terminal or PC terminates the free-run mode.
Note that in the free-run mode, the results are held on both the LED and the reject output until the next
inspection cycle while in normal press operation, the reject output is unconditionally set to the reject mode
when the enable signal is removed.
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