ETC HEDS-55XX

H
Quick Assembly
Two and Three Channel Optical
Encoders
Technical Data
Features
• Two Channel Quadrature
Output with Optional Index
Pulse
• Quick and Easy Assembly
• No Signal Adjustment
Required
• External Mounting Ears
Available
• Low Cost
• Resolutions Up to 1024
Counts Per Revolution
• Small Size
• -40 °C to 100 °C Operating
Temperature
• TTL Compatible
• Single 5 V Supply
Description
The HEDS-5500/5540, HEDS5600/5640, and HEDM-5500/
5600 are high performance, low
cost, two and three channel
optical incremental encoders.
These encoders emphasize high
reliability, high resolution, and
easy assembly.
Each encoder contains a lensed
LED source, an integrated circuit
HEDM-550X/560X
HEDS-550X/554X
HEDS-560X/564X
with detectors and output
circuitry, and a codewheel which
rotates between the emitter and
detector IC. The outputs of the
HEDS-5500/5600 and HEDM5500/ 5600 are two square waves
in quadrature. The HEDS-5540
and 5640 also have a third channel index output in addition to the
two channel quadrature. This
index output is a 90 electrical
degree, high true index pulse
which is generated once for each
full rotation of the codewheel.
The HEDS series utilizes metal
codewheels, while the HEDM
series utilizes a film codewheel
allowing for resolutions to 1024
CPR. The HEDM series is nont
available with a third channel
index.
These encoders may be quickly
and easily mounted to a motor.
For larger diameter motors, the
HEDM-5600, and HEDS-5600/
5640 feature external mounting
ears.
The quadrature signals and the
index pulse are accessed through
five 0.025 inch square pins
located on 0.1 inch centers.
Standard resolutions between 96
and 1024 counts per revolution
are presently available. Consult
local Hewlett-Packard sales representatives for other resolutions.
Applications
The HEDS-5500, 5540, 5600,
5640, and the HEDM-5500, 5600
provide motion detection at a low
cost, making them ideal for high
volume applications. Typical
applications include printers,
plotters, tape drives, positioning
tables, and automatic handlers.
ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC DISCHARGE.
2-90
5965-5875E
Package Dimensions
MOTION SENSING
AND CONTROL
HEDS-5500/5540, HEDM-5500
*Note: For the HEDS-5500 and HEDM-5500, Pin #2 is a No Connect. For the HEDS-5540, Pin #2 is CH. I, the index output.
HEDS-5600/5640, HEDM-5600
*Note: For the HEDS-5600 and HEDM-5600, Pin #2 is a No Connect. For the HEDS-5640, Pin #2 is CH. I, the index output.
2-91
Theory of Operation
Block Diagram
The HEDS-5500, 5540, 5600,
5640, and HEDM-5500, 5600
translate the rotary motion of a
shaft into either a two- or a threechannel digital output.
As seen in the block diagram,
these encoders 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
codewheel. 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, A, B and B
(also I and I in the HEDS-5540
and 5640). 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).
In the HEDS-5540 and 5640, the
output of the comparator for I
and I is sent to the index
processing circuitry along with
the outputs of channels A and B.
2-92
The final output of channel I is an
index pulse PO which is generated
once for each full rotation of the
codewheel. This output PO is a
one state width (nominally 90
electrical degrees), high true
index pulse which is coincident
with the low states of channels A
and B.
Definitions
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.
Position Error ( ∆Θ): The
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.
State Width Error ( ∆S): The
deviation, in electrical degrees, of
each state width from its ideal
value of 90°e.
Phase (φ): The number of
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
of the phase from its ideal value
of 90°e.
Absolute Maximum Ratings
HEDS-55XX/56XX
HEDM-550X/560X
Storage Temperature, TS
-40°C to 100°C
-40°C to +70°C
Operating Temperature, TA
-40°C to 100°C
-40°C to +70°C
Supply Voltage, VCC
-0.5 V to 7 V
-0.5 V to 7 V
Output Voltage, VO
-0.5 V to VCC
-0.5 V to VCC
Output Current per Channel, IOUT
-1.0 mA to 5 mA
-1.0 mA to 5 mA
Vibration
20 g, 5 to 1000 Hz
20 g, 5 to 1000 Hz
Shaft Axial Play
± 0.25 mm (± 0.010 in.)
± 0.175 mm (± 0.007 in.)
Shaft Eccentricity Plus Radial Play
0.1 mm (0.004 in.) TIR
0.04 mm (0.0015 in.) TIR
Velocity
30,000 RPM
30,000 RPM
Acceleration
250,000 rad/sec2
250,000 rad/sec2
Direction of Rotation: When the
codewheel rotates in the counterclockwise direction (as viewed
from the encoder end of the
motor), channel A will lead
channel B. If the codewheel
rotates in the clockwise direction,
channel B will lead channel A.
Output Waveforms
Index Pulse Width (PO ): The
number of electrical degrees that
an index output is high during
one full shaft rotation. This value
is nominally 90°e or 1/4 cycle.
2-93
MOTION SENSING
AND CONTROL
Parameter
Recommended Operating Conditions
Parameter
Symbol Min.
Typ.
Max.
Units
Notes
Temperature HEDS Series
TA
-40
100
°C
Temperature HEDM Series
TA
-40
70
°C
Supply Voltage
VCC
4.5
5.5
Volts
Load Capacitance
CL
100
pF
2.7 kΩ pull-up
Count Frequency
f
100
kHz
Velocity (rpm) x N/60
Shaft Perpendicularity
Plus Axial Play (HEDS Series)
± 0.25
(± 0.010)
mm
(in.)
6.9 mm (0.27 in.) from
mounting surface
Shaft Eccentricity Plus
Radial Play (HEDS Series)
0.04
mm (in.)
(0.0015)
TIR
6.9 mm (0.27 in.) from
mounting surface
Shaft Perpendicularity
Plus Axial Play (HEDM Series)
± 0.175
(± 0.007)
6.9 mm (0.27 in.) from
mounting surface
Shaft Eccentricity Plus
Radial Play(HEDM Series)
0.04
mm (in.)
(0.0015)
TIR
5.0
mm
(in.)
non-condensing atmosphere
Ripple < 100 mVp-p
6.9 mm (0.27 in.) from
mounting surface
Note: The module performance is guaranteed to 100 kHz but can operate at higher frequencies. 2.7 kΩ pull-up resistors
required for HEDS-5540 and 5640.
Encoding Characteristics
Encoding Characteristics over Recommended Operating Range and Recommended Mounting Tolerances
unless otherwise specified. Values are for the worst error over the full rotation.
Part No.
Description
Sym.
Min.
Typ.*
Max.
Units
HEDS-5500
HEDS-5600
(Two Channel)
Pulse Width Error
Logic State Width Error
Phase Error
Position Error
Cycle Error
∆P
∆S
∆φ
∆Θ
∆C
7
5
2
10
3
45
45
20
40
5.5
°e
°e
°e
min. of arc
°e
HEDM-5500
HEDM-5600
(Two Channel)
Pulse Width Error
Logic State Width Error
Phase Error
Position Error
Cycle Error
∆P
∆S
∆φ
∆Θ
∆C
10
10
2
10
3
45
45
15
40
7.5
°e
°e
°e
min. of arc
°e
HEDS-5540
HEDS-5640
(Three
Channel)
Pulse Width Error
Logic State Width Error
Phase Error
Position Error
Cycle Error
Index Pulse Width
∆P
∆S
∆φ
∆Θ
∆C
PO
55
5
5
2
10
3
90
35
35
15
40
5.5
125
°e
°e
°e
min. of arc
°e
°e
CH. I rise after
-25°C to +100°C
CH. A or CH. B fall -40°C to +100°C
t1
t1
10
-300
100
100
250
250
ns
ns
CH. I fall after
-25°C to +100°C
CH. B or CH. A rise -40°C to +100°C
t2
t2
70
70
150
150
300
1000
ns
ns
Note: See Mechanical Characteristics for mounting tolerances.
*Typical values specified at VCC = 5.0 V and 25°C.
2-94
Electrical Characteristics
Electrical Characteristics over Recommended Operating Range.
HEDS-5500
HEDS-5600
Parameter
Supply Current
High Level Output Voltage
Low Level Output Voltage
Rise Time
Fall Time
HEDS-5540
HEDS-5640
HEDM-5500
HEDM-5600
Supply Current
High Level Output Voltage
Low Level Output Voltage
HEDM-5500
HEDM-5600
Supply Current
High Level Output Voltage
Low Level Output Voltage
Rise Time
Fall Time
Rise Time
Fall Time
Sym.
Min.
ICC
VOH
VOL
2.4
tr
tf
Units
17
40
mA
V
V
IOH = -40 µA max.
IOL = 3.2 mA
ns
ns
CL = 25 pF
RL = 11 kΩ pull-up
mA
V
V
IOH = -200 µA max.
IOL = 3.86 mA
ns
ns
CL = 25 pF
RL = 2.7 kΩ pull-up
mA
V
V
IOH = -40 µA max.
IOL = 3.86 mA
ns
ns
CL = 25 pF
RL = 3.2 kΩ pull-up
200
50
30
2.4
57
85
0.4
tr
tf
ICC
VOH
VOL
Max.
0.4
tr
tf
ICC
VOH
VOL
Typ.*
180
40
30
2.4
57
85
0.4
180
40
Notes
*Typical values specified at VCC = 5.0 V and 25°C.
2-95
MOTION SENSING
AND CONTROL
Part No.
Mechanical Characteristics
Parameter
Symbol
Codewheel Fits These
Standard Shaft Diameters
Dimension
Tolerance[1]
Units
2 3 4
5 6 8
+0.000
-0.015
mm
+0.0000
-0.0007
in
5/32
3/16
Moment of Inertia
J
1/8
1/4
0.6 (8.0 x 10-6)
g-cm2 (oz-in-s2)
14.0 (0.55)
± 0.5
(± 0.02)
mm
(in.)
2 screw
mounting
19.05
(0.750)
± 0.13
(± 0.005)
mm
(in.)
3 screw
mounting
20.90
(0.823)
± 0.13
(± 0.005)
mm
(in.)
external
mounting ears
46.0
(1.811)
± 0.13
(± 0.005)
mm
(in.)
2 screw
mounting
M 2.5 or (2-56)
mm (in.)
3 screw
mounting
M 1.6 or (0-80)
mm (in.)
external
mounting ears
M 2.5 or (2-56)
mm (in.)
0.33 (0.130)
mm (in.)
(2-56)
(in.)
Required Shaft Length[2]
Bolt Circle[3]
Mounting Screw Size[4]
Encoder Base Plate
Thickness
Hub Set Screw
Notes:
1. These are tolerances required of the user.
2. The HEDS-55X5 and 56X5, HEDM-5505, 5605 provide an 8.9 mm (0.35 inch) diameter hole through the housing for longer motor
shafts. See Ordering Information.
3. The HEDS-5540 and 5640 must be aligned using the aligning pins as specified in Figure 3, or using the alignment tool as shown in
“Encoder Mounting and Assembly”. See also “Mounting Considerations.”
4. The recommended mounting screw torque for 2 screw and external ear mounting is 1.0 kg-cm (0.88 in-lbs). The recommended
mounting screw torque for 3 screw mounting is 0.50 kg-cm (0.43 in-lbs).
Electrical Interface
To insure reliable encoding
performance, the HEDS-5540 and
5640 three channel encoders
require 2.7 kΩ (± 10%) pull-up
resistors on output pins 2, 3, and
5 (Channels I, A, and B) as shown
in Figure 1. These pull-up
resistors should be located as
2-96
close to the encoder as possible
(within 4 feet). Each of the three
encoder outputs can drive a single
TTL load in this configuration.
The HEDS-5500, 5600, and
HEDM-5500, 5600 two channel
encoders do not normally require
pull-up resistors. However, 3.2 kΩ
pull-up resistors on output pins 3
and 5 (Channels A and B) are
recommended to improve rise
times, especially when operating
above 100 kHz frequencies.
Mounting Considerations
The HEDS-5540 and 5640 three
channel encoders and the HEDM
Series high resolution encoders
must be aligned using the aligning
pins as specified in Figure 3, or
using the HEDS-8910 Alignment
Tool as shown in Encoder
Mounting and Assembly.
two channel encoders are
attached to a motor with the screw
sizes and mounting tolerances
specified in the mechanical
characteristics section without
any additional mounting bosses,
the encoder output errors will be
within the maximums specified in
the encoding characteristics
section.
The use of aligning pins or
alignment tool is recommended
but not required to mount the
HEDS-5500 and 5600. If these
The HEDS-5500 and 5540 can be
mounted to a motor using either
the two screw or three screw
mounting option as shown in
Figure 2. The optional aligning
pins shown in Figure 3 can be
used with either mounting option.
The HEDS-5600, 5640, and
HEDM-5600 have external
mounting ears which may be used
for mounting to larger motor base
plates. Figure 4 shows the
necessary mounting holes with
optional aligning pins and motor
boss.
11.10 / 10.94
(0.438 / 0.431)
2.39 / 2.34
(0.096 / 0.092)
Figure 2. Mounting Holes.
Figure 3. Optional Mounting Aids.
2-97
MOTION SENSING
AND CONTROL
Figure 1. Pull-up Resistors on HEDS-5X40 Encoder Outputs.
2.39 / 2.34
(0.096 / 0.092)
0.25 (0.010) X
45° CHAMFER
2 PLACES
A Ø 0.15 (0.006)
0.8 (0.03) X 45° CHAMFER
O A 0.05 (0.002)
11.10 / 10.94
(0.438 / 0.431)
Figure 4. Mounting with External Ears.
2-98
MOTION SENSING
AND CONTROL
Encoder Mounting and Assembly
1. For HEDS-5500 and 5600: Mount encoder base plate onto
motor. Tighten screws. Go on to step 2.
2. Snap encoder body onto base plate locking all 4 snaps.
1a. For HEDS-5540, 5640 and HEDM-5500, 5600: Slip
alignment tool onto motor shaft. With alignment tool in
place, mount encoder baseplate onto motor as shown above.
Tighten screws. Remove alignment tool.
3a. Push the hex wrench into the body of the encoder to
ensure that it is properly seated into the code wheel hub set
screws. Then apply a downward force on the end of the hex
wrench. This sets the code wheel gap by levering the code
wheel hub to its upper position.
4. Use the center screwdriver slot, or either of the two side
slots, to rotate the encoder cap dot clockwise from the one
dot position to the two dot position. Do not rotate the
encoder cap counterclockwise beyond the one dot position.
The encoder is ready for use!
3b. While continuing to apply a downward force, rotate the
hex wrench in the clockwise direction until the hub set
screw is tight against the motor shaft. The hub set screw
attaches the code wheel to the motor's shaft.
3c. Remove the hex wrench by pulling it straight out of the
encoder body.
2-99
Connectors
Manufacturer
Part Number
AMP
103686-4
640442-5
Dupont/Berg
65039-032 with 4825X-000 term.
HP
(designed to mechanically lock into the
HEDS-5XXX, HEDM-5X0X Series)
HEDS-8902 (2 ch.) with 4-wire leads
Molex
2695 series with 2759 series term.
HEDS-8903 (3 ch.) with 5-wire leads
*
N/A*
*
Figure 5. HEDS-8902 and 8903 Connectors.
Typical Interfaces
HEDS–55XX
CH. A
OR
HEDS-56XX CH. B
OR
HEDM-5X0X
HP
HCTL-2016/
2020
QUADRATURE
DECODER/
COUNTER
HOST
PROCESSOR
HEDS–55XX
CH. A
OR
HEDS-56XX CH. B
OR
HEDM-5X0X
HP
HCTL-1100
MOTION
CONTROL IC
HOST
PROCESSOR
2-100
Ordering Information
Encoders with Metal Codewheels
Mounting Type
5 - Standard
6 - External
Mounting Ears
Outputs
0 - 2 Channel
4 - 3 Channel
Option
Through Hole
0 - None
5 - 8.9 mm (0.35 in.)
Resolution (Cycles/Rev)
(HEDS-550X, 560X 2 Channel)
S - 50 CPR
F - 256 CPR
K - 96 CPR
G - 360 CPR
C - 100 CPR
H - 400 CPR
D - 192 CPR
A - 500 CPR
E - 200 CPR
I - 512 CPR
Shaft Diameter
01 - 2 mm
06 - 1/4 in.
02 - 3 mm
11 - 4 mm
03 - 1/8 in.
14 - 5 mm
04 - 5/32 in.
12 - 6 mm
05 - 3/16 in.
13 - 8 mm
(HEDS-554X, 564X 3 Channel)
G - 360 CPR
S - 50 CPR
H - 400 CPR
K - 96 CPR
A - 500 CPR
C - 100 CPR
I - 512 CPR
E - 200 CPR
F - 256 CPR
HEDS-8910 0
Alignment Tool
(Included with each order of HEDS-554X/564X three channel encoders)
Encoders with Film Codewheels
HEDM-5
Mounting Type
5 - Standard
6 - External
Mounting Ears
Outputs
0 - 2 Channel
0
Through Hole
0 - None
5 - 8.9 mm (0.35 in.)
HEDS-8910
0
Option
Resolution (Cycles/Rev)
B - 1000 CPR
J - 1024 CPR
Shaft Diameter
01 - 2 mm
06 - 1/4 in.
02 - 3 mm
11 - 4 mm
03 - 1/8 in.
14 - 5 mm
04 - 5/32 in.
12 - 6 mm
05 - 3/16 in.
13 - 8 mm
Alignment Tool
(Included with each order of HEDM-550X/560X two channel encoders)
2-101
MOTION SENSING
AND CONTROL
HEDS-5