Rockwell Automation 42FT Self-Teach Fiber Optic - Manual (Page 4)

4
from fiber optic cable to reflector. Press and release the
SET button twice.
The SET indicator blinks OFF, briefly, after each press of
the SET button to confirm the Sensor has been set to
maximum sensitivity.
3. Set Mode Switch to AUTO or one of the RUN positions
(see the description of operation in the Mode Switch
section).
Adjusting Sensitivity
Increase—Set the Mode Switch to SENS +.
Decrease—Set the Mode Switch to SENS –.
1. Press and release the SET button. Sensitivity is increased
(or decreased) each time the SET button is pressed and
released. Press and release the SET button until the
desired sensitivity is reached. The SET indicator turns off
once, briefly, each time until the limit of the adjustment
range is reached. The SET indicator no longer blinks
when the upper or lower limit has been reached.
2. Set Mode Switch to AUTO or one of the RUN positions
(see the description of operation in the Mode Switch
section).
Adjusting Hysteresis
Increase—Set the Mode Switch to HYS +.
Decrease—Set the Mode Switch to HYS –.
1. Press and release the SET button. Hysteresis is increased
(or decreased) each time the SET button is pressed and
released. Press and release the SET button until the
desired hysteresis is reached. The emitted light at the fiber
tip and the SET indicator turn off once, briefly, each time
until the limit of the adjustment range is reached. The
emitted light at the fiber tip and the SET indicator no
longer blink when the upper or lower limit has been
reached.
2. Set Mode Switch to AUTO or one of the RUN positions
(see the description of operation in the Mode Switch
section).
Self Diagnostic/Stability Output
Self Diagnostic Upon Power Up
The sensor has a built-in self diagnostic program. Upon power
up, this program verifies that sufficient input light is being
detected.
Upon power up the light received by the sensor is measured
for 3 seconds. If the light is below +1 (1.2X margin), the
stability output signal is turned on.
Application Quality Verification
In diffuse applications, it is desirable to have a margin of less
than 0.8X when the target is absent and a margin of greater
than 1.2X when the target is present.
In transmitted beam and retroreflective applications, it is
desirable to have a margin of greater than 1.2X when the
target is absent and a margin of less than 0.8X when a target
is present.
The diagnostic output of the 42FT will turn on when application
margin levels are not less than 0.8X or greater than 1.2X for
seven successive detections.
If seven consecutive input signals are below the +1 level (1.2X
margin), the stability output signal turns on to indicate that the
application is not stable (see
Ê ).
If seven consecutive input signals are above the –1 level (0.8X
margin), the stability output signal turns on to indicate that the
application is not stable (see
Ë ).
Stability Output
On
Off
Instability
Range
1.2:1
0.8:1
1:1
Input Signal
Level
On On
Off Off
Stability Output
Level -1
Level +1
Ê 7 Low Margin Detections
Trip Stability Output
Ë 7 High Margin Detections
Trip Stability Output
Publication 75009–056–01(E)
May 1999
Printed in Japan