Agilent HEDB-9040 and HEDB-9140
Three Channel Optical
Incremental Encoder Modules
Bundle With Codewheel
Data Sheet
Features
•
Two Channel Quadrature Output
with Index Pulse
•
Resolution from 100 CPR Up To
1024 CPR (Counts Per Revolution)
•
Low Cost
•
Easy to Mount
•
No Signal Adjustment required
•
Small Size
•
Operating Temperature :
-40
o
C to 100
o
C
•
TTL Compatible
The HEDB-9040 is designed
for use with a HEDS-6140
codewheel which has an
optical radius of 23.36 mm
(0.920 inch).The HEDB-9140 is
designed for use with a HEDS-
5140 codewheel which has an
optical radius of 11.00 mm
(0.433 inch).
The quadrature signals and the
index pulse are accessed
through five 0.025 inch square
pins located on 0.1 inch
(pitch) centers.
•
Single 5V Supply
Applications
The HEDB-9040 and 9140
provide sophisticated motion
control detection at a low cost,
making them ideal for high
volume applications. Typical
applications include printers,
plotters, tape drives, and
industrial and factory
automation equipment.
Note: Agilent Technologies encoders are not
recommended for use in safety critical
applications. Eg. ABS braking systems, power
steering, life support systems and critical care
medical equipment. Please contact sales
representative if more clarification is needed.
Description
The HEDB-9040 and HEDB-
9140 series are three channel
optical incremental encoder
modules offered with a
codewheel. When used with a
codewheel, these low cost
modules detect rotary position.
Each module consists of a
lensed LED source and a
detector IC enclosed in a small
plastic package. Due to a
highly collimated light source
and a unique photodetector
array, these modules are
extremely tolerant to mounting
misalignment.
The HEDB-9040 and 9140 has
two channel quadrature
outputs plus a third channel
index output. This index
output is a 90 electrical degree
high true index pulse which is
generated once for each full
rotation of the codewheel.
1
Theory of Operation
The HEDB-9040 and 9140 is
emitter/detector modules.
Coupled with a codewheel,
these modules translate the
rotary motion of a shaft into a
three-channel digital output.
As seen in Figure 1, the
modules contain a single Light
Emitting Diode (LED) as its
light source. The light is
collimated into a parallel beam
by means of a single
polycarbonate lens located
directly over the LED.
Opposite the emitter is the
integrated detector circuit. This
IC consists of multiple sets of
photodetectors and the signal
processing circuitry necessary
to produce the digital
waveforms.
The codewheel rotates between
the emitter and detector,
causing the light beam to be
interrupted by the pattern of
spaces and bars on the
codewheel.
The photodiodes which detect
these interruptions are
arranged in a pattern that
corresponds to the radius and
design of the code-wheel.
These detectors are also
spaced such that a light period
on one pair of detectors
corresponds to a dark period
on the adjacent pair of
detectors.
The photodiode outputs are
then fed through the signal
processing circuitry resulting
in A, Abar, B, Bbar, I and
Ibar. Comparators receive
these signals and produce the
final outputs for channels A
and B. Due to this integrated
phasing technique, the digital
output of channel A is in
quadrature with that of
channel B (90 degrees out of
phase).
Definitions
Note: Refer to Figure 2
Count (N):
The number of bar
and window pairs or counts
per revolution (CPR) of the
codewheel.
One Cycle (C):
360 electrical
degrees (°e), 1 bar and
window pair.
One Shaft Rotation:
360
mechanical degrees, N cycles.
∆Θ
Position Error (∆Θ
The
∆Θ):
normalized angular difference
between the actual shaft
position and the position
indicated by the encoder cycle
count.
Cycle Error (∆C):
An
∆
indication of cycle uniformity.
The difference between an
observed shaft angle which
gives rise to one electrical
cycle, and the nominal angular
increment of 1/N of a
revolution.
Pulse Width (P):
The number
of electrical degrees that an
output is high during 1 cycle.
This value is nominally 180°e
or 1/2 cycle.
Pulse Width Error (∆P):
The
∆
deviation, in electrical degrees,
of the pulse width from its
ideal value of 180°e.
State Width (S):
The number
of electrical degrees between a
transition in the output of
channel A and the neighboring
transition in the output of
channel B. There are 4 states
per cycle, each nominally 90°e.
Phase (φ):
The number of
φ
electrical degrees between the
center of the high state of
channel A and the center of
the high state of channel B.
This value is nominally 90°e
for quadrature output.
Phase Error (φ):
The deviation
φ
of the phase from its ideal
value of 90°e.
Direction of Rotation:
When
the codewheel rotates in the
clockwise direction viewing
from top of the module
(direction from V to G),
channel A will lead channel B.
If the codewheel rotates in the
opposite direction, channel B
will lead channel A.
Optical Radius (Rop):
The
distance from the codewheel’s
center of rotation to the
optical center (O.C) of the
encoder module.
Index Pulse Width (Po):
The
number of electrical degrees
that an index is high during
one full shaft rotation. This
value is nominally 90°e or 1/4
cycle.
Specification
For encoder electrical,
mechanical specifications,
codewheel technical
specifications and additional
informations pls refer to :
•
HEDS-9040 /9140 datasheet.
•
HEDS / HEDG / HEDM – 51xx /
61xx Codewheel Datasheet
2
Bundle Part Number Breakdown List
Note :The bundle part HEDB-9040/9140 consists of HEDS-9040/9140 and HEDS-6140/5140. The table below provides the breakdown list.
HEDB - 9040 - CPR
Shaft Diameter
CPR
CPR
00
Encoder Module : HEDS-9040 -
Codewheel : HEDS - 6140 -
Shaft Diameter
HEDB - 9140 - CPR
Shaft Diameter
CPR
00
Encoder Module : HEDS-9140 -
Codewheel : HEDS - 5140 -
CPR
Shaft Diameter
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For product information and a complete list
of distributors, please go to our web site.
For technical assistance call:
Americas/Canada: +1 (800) 235-0312
or (916) 788-6763
Europe: +49 (0) 6441 92460
China: 10800 650 0017
Hong Kong: (+65) 6756 2394
India, Australia, New Zealand: (+65) 6755 1939
Japan: (+81 3) 3335-8152(Domestic/Inter-
national), or 0120-61-1280(Domestic Only)
Korea: (+65) 6755 1989
Singapore, Malaysia, Vietnam, Thailand,
Philippines, Indonesia: (+65) 6755 2044
Taiwan: (+65) 6755 1843
Data subject to change.
Copyright © 2005 Agilent Technologies, Inc.
October 17, 2005
5989-4043EN
5
Analog electronics
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