HEDS-9100#A00 - Hewlett-Packard / Agilent

2-63

MOTION SENSING

AND CONTROL

Two Channel High Resolution

Optical Incremental Encoder

Modules

Technical Data

Features

• High Resolution: Up to 2048

Cycles per Revolution

• Up to 8192 Counts per

Revolution with 4X Decoding

• Two Channel Quadrature

Output

• Low Cost

• Easy to Mount

• No Signal Adjustment

Required

• Small Size

• -40°C to 100 °C Operating

Temperature

• TTL Compatible

• Single 5 V Supply

Description

The HEDS-9000 Options T and U

and the HEDS-9100 Options B

and J are high resolution two

channel rotary incremental

encoder modules. These options

are an extension of our popular

HEDS-9000 and HEDS-9100

series. When used with a code-

wheel, these modules detect

relative rotary position. The

HEDS-9200 Option 300 and 360

are high resolution linear encoder

modules. When used with a

HEDS-9000/9100/9200

Extended Resolution

Series

codestrip, these modules detect

relative linear position.

These modules consist of a lensed

Light Emitting Diode (LED)

source and detector IC enclosed

in a small C shaped plastic

package. Due to a highly

collimated light source and

unique photodetector array, these

modules provide a highly reliable

quadrature output.

The HEDS-9000 and HEDS-9100

are designed for use with

codewheels which have an optical

radius of 23.36 mm and 11 mm

respectively. The HEDS-9200 is

designed for use with a linear

codestrip.

These components produce a two

channel quadrature output which

can be accessed through five

0.025 inch square pins located on

0.1 inch centers.

The resolution of the HEDS-9000

Options T and U are 2000 and

2048 counts per revolution

respectively. The HEDS-9100

Options B and J are 1000 and

1024 counts per revolution

respectively. The HEDS-9200

Option 300 and 360 linear

encoder modules have resolutions

of 300 and 360 lines per inch.

Consult local Hewlett-Packard

sales representatives for other

resolutions.

Theory of Operation

The diagram shown on the fol-

lowing page is a block diagram of

the encoder module. As seen in

this block diagram, the module

contains a single 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

ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC

DISCHARGE.

5965-5889E

2-64

Block Diagram

of multiple sets of photodetectors

and the signal processing

circuitry necessary to produce the

digital waveforms.

The codewheel/codestrip passes

between the emitter and detector,

causing the light beam to be

interrupted by the pattern of

spaces and bars on the code-

wheel. The photodiodes which

detect these interruptions are

arranged in a pattern that

corresponds to the codewheel/

codestrip. 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. 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

Count (N): The number of bar

and window pairs or counts per

revolution (CPR) of the

codewheel.

1 cycle (C): 360 electrical degrees

(°e), 1 bar and window pair.

1 Shaft Rotation: 360 mechanical

degrees, N cycles.

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 (

): The number of elec-

trical 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.

Direction of Rotation: When the

codewheel rotates in the direction

of the arrow on top of the

module, channel A will lead

channel B. If the codewheel

rotates in the opposite direction,

channel B will lead channel A.

Optical Radius (Rop): The dis-

tance from the codewheel’s center

of rotation to the optical center

(O.C.) of the encoder module.

Output Waveforms

2-65

MOTION SENSING

AND CONTROL

Recommended Operating Conditions

Parameter Symbol Min. Typ. Max. Units Notes

Temperature TA-40 100 °C

Supply Voltage VCC 4.5 5.0 5.5 Volts Ripple < 100 mV

p-p

Load Capacitance CL100 pF 3.3 kΩ pull-up resistor

Count Frequency f 100 kHz Velocity (rpm) x N/60

Shaft Axial Play ±0.125 mm

±0.005 in.

Note: The module performance is guaranteed to 100 kHz but can operate at higher frequencies. For frequencies above 100 kHz it is

recommended that the load capacitance not exceed 25 pF and the pull up resistance not exceed 3.3 kΩ. For typical module performance

above 100 kHz please see derating curves.

Package Dimensions

Absolute Maximum Ratings

Storage Temperature, TS..................................................................... -40°C to 100°C

Operating Temperature, TA................................................................ -40°C to 100°C

Supply Voltage, V

CC ...................................................................................... -0.5 V to 7 V

Output Voltage, VO........................................................................................ -0.5 V to V

Output Current per Channel, Iout ................................................. -1.0 mA to 5 mA

26.67 (1.05)

Hp HEDS-9X00

15.2

(0.60)

17.27

(0.680)

20.96

(0.825)

1.85 (0.073)

8.64 (0.340)

REF.

ALIGNING RECESS

2.44/2.41 DIA.

(0.096/0.095)

2.16 (0.085)

DEEP

1.02 ± 0.10

(0.040 ± 0.004)

5.1 (0.20)

X00

YYXX

OPTION CODE

0.63 (0.025)

SQR. TYP. 2.54 (0.100) TYP.

DATE CODE

1.0 (0.04)

3.73 ± 0.05

(0.147 ± 0.002)

2.67 (0.105) DIA.

MOUNTING THRU

HOLE 2 PLACES

2.44/2.41 X 2.79

(0.096/0.095 X 0.110)

2.16 (0.085) DEEP

OPTICAL CENTER

1.52 (0.060)

20.8

(0.82) 11.7

(0.46)

8.6 (0.34)

1.78 ± 0.10

(0.070 ± 0.004)

2.92 ± 0.10

(0.115 ± 0.004) 10.2

(0.400)

5.46 ± 0.10

(0.215 ± 0.004)

OPTICAL

CENTER LINE

2.54

(0.100)

2.21

(0.087)

5.8

(0.23)

6.35 (0.250) REF.

ALIGNING RECESS

2.44/2.41 X 2.79

(0.096/0.095 X 0.110)

2.16 (0.085) DEEP

4.11 (0.162)

ALIGNING RECESS

2.44/2.41 DIA.

(0.096/0.095)

2.16 (0.085) DEEP

OPTICAL

CENTER

45°

8.81

(0.347)

11.9

(0.47)

4.75 ± 0.10

(0.187 ± 0.004)

2.9

(0.11)

1.8

(0.07)

6.9 (0.27)

GND

5 CH. B

4 V

3 CH. A

2 N.C.

1 GND

SIDE A SIDE B

TYPICAL DIMENSIONS IN

MILLIMETERS AND (INCHES)

10.16

(0.400)

2-66

Electrical Characteristics

Electrical Characteristics over Recommended Operating Range, typical at 25°C.

Parameter Symbol Min. Typical Max. Units Notes

Supply Current ICC 30 57 85 mA

High Level Output Voltage VOH 2.4 Volts IOH = -200 µA max.

Low Level Output Voltage VOL 0.4 Volts IOL = 3.86 mA

Rise Time tr180 ns CL = 25 pF

Fall Time tf40 ns

Encoding Characteristics

Encoding Characteristics over Recommended Operating Range and Recommended Mounting Tolerances.

These Characteristics do not include codewheel/codestrip contribution. The Typical Values are averages over

the full rotation of the codewheel. For operation above 100 kHz, see frequency derating curves.

Frequency Derating Curves

Typical performance over extended operating range. These curves were derived using a 25 pF load with a 3.3

k pull-up resistor. Greater load capacitances will cause more error than shown in these graphs.

Description Symbol Typical Maximum Units

Pulse Width Error ∆P5 45°e

Logic State Width Error ∆S3 45°e

Phase Error ∆φ 215°e

Note: Module mounted on tolerance circle of ±0.13 mm (±0.005 in.) radius referenced from module Side A aligning recess centers. 3.3

kΩ pull-up resistors used on all encoder module outputs.

RL = 3.3 kΩ pull-up

-5

050 100 150 200

-40 C

+25 C

+100 C

FREQUENCY (KHz)

-10

-15

CHANGE IN STATE WIDTH ERROR

(ELECTRICAL DEGREES)

-5 050 100 150 200

-40 C

+25 C

+100 C

FREQUENCY (KHz)

CHANGE IN PULSE WIDTH ERROR

(ELECTRICAL DEGREES)

2-67

MOTION SENSING

AND CONTROL

Gap Setting for Rotary

and Linear Modules

Gap is the distance between the

image side of the codewheel and

the detector surface of the mod-

ule. This gap dimension must

always be met and codewheel

warp and shaft end play must stay

within this range. This dimension

is shown in Figure 1.

Mounting Considerations

for Rotary Modules

Figure 2 shows a mounting

tolerance requirement for proper

operation of the high resolution

rotary encoder modules. The

Aligning Recess Centers must be

located within a tolerance circle

of 0.13 mm (0.005 in.) radius

from the nominal locations. This

tolerance must be maintained

whether the module is mounted

with side A as the mounting plane

using aligning pins (see Figure 3),

or mounted with Side B as the

mounting plane using an

alignment tool.

Mounting with Aligning

Pins

The high resolution rotary

encoder modules can be mounted

using aligning pins on the motor

base. (HP does not provide align-

ing pins.) For this configuration,

Side A must be used as the

mounting plane. The Aligning

Recess Centers must be located

within the 0.13 mm (0.005 in.) R

Tolerance Circle as explained

above. Figure 3 shows the

necessary dimensions.

Mounting with HP

Alignment Tools

HP offers alignment tools for

mounting HP encoder modules in

conjunction with HP codewheels,

using side B as the mounting

plane. Please refer to the HP

codewheel data sheet for more

information.

Figure 2. Rotary Module Mounting Tolerance.

Figure 3. Mounting Plane Side A.

Figure 1. Module Gap Setting.

6.63+0.51

-0.25 0.261+0.020

-0.010

()

NOTE 1

3.56+0.25

-0.51 0.140+0.010

-0.020

()

NOTE 1

SIDE B

SIDE A

IMAGE SIDE OF CODEWHEEL/CODESTRIP

CODEWHEEL/CODESTRIP

NOTES: 1. THESE DIMENSIONS INCLUDE CODEWHEEL/CODESTRIP WARP AND SHAFT END PLAY.

2. DIMENSIONS IN MILLIMETERS AND (INCHES).

NOTE 1: RECOMMENDED MOUNTING SCREW TORQUE IS 4 KG-CM (3.5 IN-LBS).

2 PLACES

NOTE 1

2-68

Mounting Considerations for Linear Modules

Mounting Plane Side A Mounting Plane Side B

2-69

MOTION SENSING

AND CONTROL

STATIC CHARGE WARNING: LARGE STATIC CHARGE ON CODESTRIP MAY HARM MODULE.

PREVENT ACCUMULATION OF CHARGE.

Figure 4. Codestrip Design

Parameter Symbol Minimum Maximum Units Notes

Window/Bar Ratio φw/φb0.7 1.4

Window Length Lw1.8 (0.07) mm (inch)

Absolute Maximum Rcmm Includes eccentricity

Codewheel Radius (inch) errors

Rop

1.9

(0.075)

Recommended Codewheel Characteristics

Mounting as Referenced to Side A Mounting as Referenced to Side B

Recommended Codestrip Characteristics and Alignment

Codestrip design must take into consideration mounting as referenced to either side A or side B (see Figure 4).

Mounting Ref. Mounting Ref.

Parameter Symbol Side A Side B Units

Window/Bar Ratio Ww/Wb0.7 min., 1.4 max. 0.7 min., 1.4 max.

Window Distance L La ≤0.51 (0.020) Lb ≥3.23 (0.127) mm (inch)

Window Edge to S 0.90 (0.035) min. 0.90 (0.035) min. mm (inch)

Module Opt Center Line

Parallelism α1.3 max. 1.3 max. deg.

Module to Codestrip

Note: All parameters and equations must be satisfied over the full length of codestrip travel including maximum codestrip runout.

2-70

Connectors

Manufacturer Part Number Mounting Surface

AMP 103686-4 Both

640442-5 Side B

DuPont 65039-032 with 4825X-000 term. Both

HP HEDS-8902 with 4-wire leads Side B (see Fig. 7)

Molex 2695 series with 2759 series term. Side B

Figure 7. HEDS-8902 Connector.

2-71

MOTION SENSING

AND CONTROL

Ordering Information

HEDS-9200 Option

Resolution

(Cycles/Rev)

300 - 300 LPI

360 - 360 LPI

HEDS-9100 Option 0 0

Resolution

(Cycles/Rev)

B - 1000 CPR

J - 1024 CPR

HEDS-9000 Option 0 0

Resolution

(Cycles/Rev)

T - 2000 CPR

U - 2048 CPR

Two Channel Encoder Modules with a 23.36 mm Optical Radius

Two Channel Encoder Modules with an 11.00 mm Optical Radius

Two Channel Linear Encoder Module

*Codewheel Information

For information on matching codewheels and

accessories for use with HP rotary encoder modules,

please refer to the HP Codewheel Data sheet HEDS-

5120/6100, HEDG-5120/6120, HEDM-5120/6120

Note: For lower resolutions, please refer to HEDS-9000/9100 and

HEDS-9200 data sheets for detailed information.