Dynamic teach and adaptive thresholds – Banner FI22 Expert Series User Manual
Page 5
P/N 108899 rev. C
5
FI22FP Low-Profile Inline Plastic Fiber Optic Sensor
Banner Engineering Corp.
•
Minneapolis, MN U.S.A.
www.bannerengineering.com • Tel: 763.544.3164
Dynamic TEACH and Adaptive Thresholds
• Teach on-the-fly
• Sets a single switching threshold
• Threshold position is adjustable using “+” and “-” buttons (Manual Adjust)
Dynamic TEACH is best used when a machine or process may not be stopped for
teaching. A variation of two-point TEACH, it programs the sensor during actual machine
run conditions, taking multiple samples of the light and dark conditions and automatically
setting the threshold at the optimum level (see Figure 3).
Dynamic TEACH activates the sensor’s adaptive threshold system, which continuously
tracks minimum and maximum signal levels, and automatically maintains centering of the
switch point between the light and dark conditions. The adaptive threshold system remains
in effect during RUN mode. The adaptive routine saves to non-volatile memory at least once
per hour.
When Dynamic TEACH mode is used, the output ON state (light or dark operate) will remain
as it was last programmed. To change the output ON state, use SETUP mode (see page 7).
The sensing set point may be adjusted (fine-tuned) whenever the sensor is in RUN mode by
clicking the “+” and “-” buttons. However, when a manual adjustment is made, the adaptive
threshold system is disabled (cancelled).
Sensor positions
threshold midway
between taught conditions
Sensor positions
threshold midway
between taught conditions
Darkest
(no signal)
Darkest
(no signal)
Most Light
(saturated
signal)
Most Light
(saturated
signal)
Single
taught
point
Sensing window size
adjusted by
Manual Adjust
Output OFF
Output OFF
Output OFF
Output ON
Output ON
Darkest Taught
Condition
Lightest Taught
Condition
Position
adjusted by
Manual Adjust
Darkest
(no signal)
Most Light
(saturated
signal)
Output OFF
Output ON
2nd Taught
Condition
1st Taught
Condition
Position
adjusted by
Manual Adjust
Figure 3. Two-Point Dynamic TEACH
(Light Operate shown)
Push Button
Remote Line
Result
Access
TEACH
Mode
• Press and Hold
> 2 seconds
• Hold remote line
low (to ground)
> 2 seconds
Power LED: OFF
Bargraph: #6 & 7 Alternately flashing
Learn
Output
ON
Condition
• Continue to hold
• Present Output ON and
OFF conditions
• Present Output ON and
OFF conditions
• Continue to hold remote
line low (to ground)
Power LED: OFF
Bargraph: #6 & 7 Alternately flashing
Learn
Output
OFF
Condition
• Release
• Release remote line/
switch
Teach Accepted
Power LED: ON
Bargraph: One LED flashes to show
relative contrast (good signal
difference shown; see table above)
Sensor returns to Run mode with new settings
Teach Unacceptable
Power LED: OFF
Bargraph: #1, 3, 5, 7 Alternately flash
to show failure
Sensor returns to Run mode
without changing settings
Bargraph
LED
Following
TEACH
Relative Signal Difference/
Recommendation
6 to 8
Excellent: Very stable operation.
4 to 5
Good: Minor sensing variables
will not affect sensing reliability.
2 to 3
Low: Minor sensing variables
may affect sensing reliability.
1
Unreliable: Consider an
alternate sensing scheme.
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T
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T
T
T T T
T
T
T
T
T
T
T
T
T
T
T
T
T T T
T
T
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T
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