Prevention of detection errors due to a drop in light level

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Application Guide
CP-PC-2250E-003
Prevention of detection errors due to a drop in light level
Digital fiber-optic sensor
HPX-AG02
alarm output model
Special function:
Light-level drop alarm output
In addition to the regular detection output, the
HPX-AG02 has a separate alarm output that
warns the user if the incoming light level drops.
■ Conditions for light-level drop alarm output
An alarm signal is output when the
incoming light level falls below a
reference level by a preset amount.
Incoming
light level
Reference
light level
■ Various causes for light level drop
Improves equipment
reliability
Setting of light-level drop amount
1 to 10%: 1% intervals
10 to 50%: 5% intervals
Change in the target object
Change in its surroundings
Dirt on detecting
surface of fiber unit
Promotes preventive
maintenance
Set value
300ms
Bent or broken
fiber unit
Fiber unit mounting
position displacement
Readjustment or
cleaning required
Light-level drop
alarm output
Detection
output (DO)
Drop in light level
of emitter LED
Use of light-level drop alarm output is recommended for thru scan fiber units, where a reference light level is
easily determined. For diffuse scan fiber units, stability safety margin alarm output is recommended. The HPXAG02 offers a selection of either light-level drop alarm output or stability safety margin alarm output.
APC (auto power control)
is made for this problem.
■ Setting method for light- After the light-level drop amount (%) has been set, the reference light level is taken from the incoming
light level, either the greater of two levels in 2-point auto tuning, or the incoming light level during
level drop alarm output % tuning. The threshold for light-level drop output is determined based on the incoming light level.
■
Setting when the light-level drop amount is 10% and percent tuning is 70%.
When re-tuning is done after light-level drop alarm output.
Tuning under
these conditions
Incoming
light level
Threshold for lightlevel drop output
Without
a target object
Tuning under
these conditions
Change to reference light level
30%
10%
Incoming
light level
Incoming light level
Without
a target object
Incoming light level
Threshold for lightlevel drop output
Detection output
set value
Light-level drop amount
is also set at re-tuning.
Change to new reference light level
Incoming light level
30%
10%
Incoming light level
Detection output
set value
Target object present
Target object present
Note: Assumes that sensor is set for DO (Dark-ON) operation with a thru-scan fiber unit.
■ Related function Remote tuning
Long term reliability
The HPX-AG02 Series allows auto tuning remotely by an external device.
Light-level drop alarm output can be also set up by remote tuning at the same time.
ON
Environment has
worsened due to
paper powder.
Flexibility for tooling
changes
Key lock prevents accidental
setting errors
Even if the amplifier keys are locked,
remote tuning by an external device
is possible.
Application Guide
■ External dimensions
■ Selection guide
Catalog listing
NPN
Features
HPX-AG02-1S
Remote tuning input
Alarm output (light-level drop and stability safety margin)
(Unit: mm)
0°
14
95.5
10
5°
Note: To use light-level drop alarm output or stability safety margin alarm output in a reduced wiring
installation, select an HPX-AG04 Series sensor.
10
15.9
(3.3 dia. hole)
12 to 24Vdc
3.7
1
70.2
Mounting bracket *1
Blue
External input 1
(35.2)
1
(3-3.3)
50mA
(4.2)
Load
3.4
50mA
Output 2
Main circuit
6.2
Load
Black
5.5
Output 1
*3
11.2
Brown
30.2
33.9
■ I/O circuit and connections (NPN type)
(3-2.2)
Pink
(25.2)
Note: In addition to light-level drop and stability safety margin alarm outputs, output 2 produces an
APC signal, allowing the user to know if APC (auto power control) ends. The APC signal is output
regardless of whether one of the above two alarm outputs is selected.
(16)
Notes:
*1. Mounting bracket sold separately (catalog listing: HPX-PA04).
2. Materials
Case: PC resin, black Control panel cover: PC resin, transparent gray
Mounting bracket: Stainless steel plate
*3. Oil-resistant cable.
Outer diameter 4.2, insulator diameter 1.2, and nominal cross-section 0.2mm2. Sheath color is gray.
■ Related products
HPX-AG03
Improves
equipment
reliability
Remote tuning error output model
If a tuning error occurs during tuning,
HPX-AG04
Advanced timer model
■ Output latch
an alarm signal is output. The HPX-AG03
Used for interlock
When an object is detected (or is not detected), latched output is
Series allows full auto-tuning remotely.
turned ON, and remains ON no matter what the detection status is.
During
operation, the amplifier display blinks.
Detection
status
Remote tuning input
Tuning error output
Insufficient light level,
insufficient light level
difference, etc.
Output
status
If a highly volatile liquid such as IPA has
leaked, latched output will stay ON even after
the liquid has evaporated. (Used in combination
with the HPF-D040 liquid leak fiber-optic detector.)
OFF by latch
cancellation
Please read the "Terms and Conditions" from the following URL before
ordering or use:
http://www.azbil.com/products/bi/order.html
Other product names, model numbers and company names may be trademarks of the respective company.
[Notice] Specifications are subject to change without notice.
No part of this publication may be reproduced or duplicated
without the prior written permission of Azbil Corporation.
Yamatake Corporation changed its name to Azbil Corporation on April 1, 2012.
1-12-2 Kawana, Fujisawa
Kanagawa 251-8522 Japan
URL: http://www.azbil.com
1st Edition : Issued in Mar. 2006-ST
3rd Edition: Issued in Apr. 2013-AZ
(10)
CP-PC-2250E-003
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