Dear Customer,
You have in your hand a brochure featuring
some of the finest position-sensing devices in
the world. As an industrial consumer, you
demand the highest quality and reliability in
the products you purchase. With over 30 years
in the
industrial encoder business we
understand your needs and have designed
products of uncompromising quality and
performance. BEI has grown to be the leader
in the industrial encoder market by keeping
promises and standing by our customers.
Chances are you heard about us from one of
your colleagues. Word of mouth has always
been our best advertising.
Please call the factory on our toll free line with
any questions regarding our products or your
application. You will find that our professional applications engineers and order specialists are both
knowledgeable and easy to talk with. We challenge you to keep us busy helping you find more and better ways
to use our products.
Our customers' satisfaction is the key to our growth. So, if you are ever unhappy for any reason with any aspect
of our performance and do not receive what you feel is a satisfactory resolution, please contact me directly
and I will make every effort to address your concerns. After all, our continued success depends on it.
Sincerely,
Glenn Avolio,
General Manager,
BEI Industrial Encoders
Custom Sensors & Technologies
Committed to Quality
B
E
I
I
n
d
u
s
t
r
i
a
l
E
n
c
o
d
e
r
s
BEI Industrial Encoders was founded
more than 30 years ago. Our goal was to produce well-made
optical encoders specifically for the industrial marketplace.
We also wanted to create a new standard for excellence by
providing on-time delivery, customer support and reasonable
lead times—all at a fair price. Today, as an ISO registered
company, we continue to build on that tradition.
Our products have grown to include electronic interfaces,
accessory items and specialized products, like those certi-
fied for hazardous area use and wash-down environments.
We offer lead times of one to three days on standard
Express Encoders®, and two weeks on a wide variety of cus-
tom encoders (specialty products can take a little longer).
We regularly fulfill our delivery commitments with an aver-
age on-time delivery record of better than 99%.
Our custom-designed factory and office facilities near Santa
Barbara, California ensure an efficient flow of production, in
which all critical manufacturing processes are tightly
controlled. High manufacturing standards, certified to
ISO9001:2000 include inspection of dozens of individual
electrical parameters on every encoder produced, as well as
confirming each unit’s mechanical compliance with its par-
ticular specifications. We stand firmly behind our products
with a two-year warranty.
We have five full-time applications specialists to help with
your technical needs— whether you want to build a model
number or need assistance with an interface issue. Our
knowledgeable order entry staff can help you specify and
order a unit that will meet your exact requirements. We
provide this high level of service to an active customer base
of thousands of companies…it’s what we do.
Presale service. Guaranteed on-time shipment. Top quality
product and technical support. We’ve preserved the found-
ing ideals of our company and make customer satisfaction
our top priority. At BEI, we are proud to be the leader in the
industrial encoder marketplace.
From our manufacturing team (top) to our applications engineers and
order specialists (above),everyone at BEI works toward a common
goal—produce the best products and deliver the best customer
service found anywhere.
800-350-2727 | BEI Industrial Encoders | 1
Specifying Guide Contents
Optical Encoder Design Guide
Repair and Support Services.......................................................................................................................Page 4
Express Encoders .......................................................................................................................................Page 5
Find-It-Fast Encoder Selection Guide...........................................................................................................Page 6
Optical Encoder Design and Operation ........................................................................................................Page 8
Typical Applications.....................................................................................................................................Page 10
Encoders and Extreme Environments ..........................................................................................................Page 12
Key Components of Optical Encoders..........................................................................................................Page 14
Installation Notes ........................................................................................................................................Page 16
Frequently Asked Questions........................................................................................................................Page 17
Incremental Encoders
Model H25 Incremental ...........................................................................................................................Page 18
Model H20 Incremental ...........................................................................................................................Page 20
Model HS25 Incremental .........................................................................................................................Page 22
Model HS35 Incremental .........................................................................................................................Page 24
Model HS45 Incremental .........................................................................................................................Page 26
Model H38 Incremental ...........................................................................................................................Page 28
Model H40 Incremental ...........................................................................................................................Page 30
Model HS20 Incremental .........................................................................................................................Page 32
Model HS22 Incremental .........................................................................................................................Page 33
Model E25 Incremental............................................................................................................................Page 34
Model L25 Incremental............................................................................................................................Page 34
Model L15 Incremental............................................................................................................................Page 35
Model M58 Incremental...........................................................................................................................Page 35
Interpolation Options................................................................................................................................Page 36
Absolute Encoders
Model H25 Absolute................................................................................................................................Page 38
Model H25X Absolute ..............................................................................................................................Page 39
Model HMT25 Absolute ...........................................................................................................................Page 40
Model L18 Absolute ................................................................................................................................Page 42
Model HS35 Absolute..............................................................................................................................Page 43
Model H38 Absolute................................................................................................................................Page 44
Model H40 Absolute................................................................................................................................Page 45
Absolute Encoder Options........................................................................................................................Page 46
2 | BEI Industrial Encoders | www.beiied.com
Hazardous and Extreme Environments
Hazardous Location Information ...............................................................................................................Page 48
Regulations and Certifications ..................................................................................................................Page 48
Drawworks Encoders...............................................................................................................................Page 49
Intrinsic Safety Barrier .............................................................................................................................Page 50
Encoders for Exreme Environments..........................................................................................................Page 51
Linear Encoders ..............................................................................................................................Page 52
SwiftComm™ Wireless Encoder Interface ................................................................Page 54
Electronic Modules ......................................................................................................................Page 58
Adapter and Accessories
Adapters .................................................................................................................................................Page 60
Accessories.............................................................................................................................................Page 62
Notes and Tables ...........................................................................................................................Page 64
B
E
I
I
n
d
u
s
t
r
i
a
l
E
n
c
o
d
e
r
s
Using This Specifying Guide
This guide has been designed to provide you with a wide range of infor-
mation on the products offered by BEI Industrial Encoders. The Design
Guide on pages 8–17 provides assistance for design engineers in speci-
fying the proper encoder for the desired application, including installation
tips and frequently asked questions.
Pages 18–47 and 52–53 detail the encoders that comprise our basic
product line. Pages 54–63 discuss optional features, wireless interfaces
and accessories for encoders.
Pages 48–51 contain hazardous area information, regulatory information,
and specialty encoders and accessories for both hazardous and extreme
environments. Pages 64–65 contain notes and tables that are referred to
throughout the preceding pages.
Ordering Encoders from BEI
The ordering information block that accompanies the description of each
of our basic products gives detailed instructions for the construction of a
model number. This system allows you to take full advantage of the
tremendous diversity of product configurations offered by BEI. If you have
questions regarding applications or the construction of a model number,
we are always happy to assist you.
Phone: 800-350-ASAP (2727) or 805-968-0782.
Fax: 805-968-3154.
©Copyright 2008, BEI Industrial Encoders, Goleta, California. All rights reserved. The
material contained herein may not be reproduced without the written consent of
BEI Industrial Encoders, Custom Sensors & Technologies
7230 Hollister Avenue, Goleta, California 93117
Specifications are subject to change without notice.
800-350-2727 | BEI Industrial Encoders | 3
Repair and Support
Count on BEI for the Best Repair and Support
Retrofits and Crossovers
Engineering Support
Our on-site sales and engineering
staff is available to help support
your engineering needs—from
deciding what type of encoder to
buy, all the way through helping
with the interface to your meas-
urement or control system.
In
addition, a regional sales manager or manufacturer’s represen-
tative is available locally to help with your system needs.
Product Specifying
Assistance
This Specifying Guide cov-
ers most of the require-
industrial
ments of the
marketplace.
If we can
explain some of the avail-
able options or you have
special
some
requirements,
please give us a call. Over the
years we have developed more
than 17 million variations on the
basic encoder, and chances are
we can answer your specific
need.
As a leader in the manufacture of
optical encoders, BEI Industrial
Encoders can also offer expertise in
crossing over a wide variety of
encoders from other manufactur-
ers, both foreign and domestic. We
maintain a thorough library of encoder specifications and
dimensional information covering
a wide range of competitive prod-
ucts.
If we cannot quote a
replacement unit from one of our
three encoder divisions, we may
be able to guide you to an
appropriate manufacturer or
repair facility to help solve your problem. We are aware of the
importance of time in a machine-down situation and handle
crossover requests in the most expeditious manner possible.
Service and Repair
All encoders produced by BEI are
backed by our two-year warranty.
If anything goes wrong, give us a
call. Our trained service person-
nel can often troubleshoot a
problem over the phone and
determine if your encoder needs to be sent in for repair. They
will perform a thorough evaluation
and recommend a course of action.
In emergency situations an evalua-
tion and repair can be underway
within minutes after the encoder is
received at our dock.
4 | BEI Industrial Encoders | www.beiied.com
Express Encoders
With BEI’s Express Encoder® Program,
You Get the Right Encoder…Right Away
Express Encoders® are popular configurations of our standard model encoders that can be built and shipped quickly. With six
package styles (four incremental and two absolute) to chose from, over 2000 different configurations —that will meet just about
any need— are available as Express Encoders.
Refer to the pages in this catalog for the Models H25, H20, HS25 and HS35 Incremental Encoders, and the Models H25
and HS35 12 bit Absolute Encoders. In the Ordering Options block at the bottom of these pages you will see the blue Express
Encoders highlight bar. By selecting from the highlighted options when constructing your model number, you will specify an
Express Encoder for your particular application.
Express Encoders ship in three days or less. We pay the freight for UPS 2nd Day Delivery when shipping to an address in
the continental United States. Certain models in the Express line are kept in stock for same day shipment (when ordered by
2:00PM pacific time).
If you need applications assistance, we are always just a phone call away. Our applications specialists are available to help with
your encoder selection. Just call 1-800-ENCODER (800-362-6337) and ask for technical assistance.
B
E
I
I
n
d
u
s
t
r
i
a
l
E
n
c
o
d
e
r
s
Express Encoders Feature:
• Two-Day Shipping on a Variety of Rotary
Optical Encoders
• Same-Day Shipping on Selected Models
• A Broad Range of Resolutions
• Heavy Duty, Environmentally Sealed Models
• Industry Standard 2.0-inch, 2.5-inch, and
3.5-inch packages
• Shafted and Hollow Shaft Styles
• Incremental and Absolute Versions
• Variable Voltage In/Out, up to 28V
• Wide Range of Available Accessories
800-350-2727 | BEI Industrial Encoders | 5
“Find-it-Fast” Selection Guide
Incremental Encoders
Model
Number
PAGE 35 L15
PAGE 20 H20
Resolution
(Max)
40,640
4096
Output
Format
ABZC
ABZC
PAGE 18 H25
PAGE 34 L25
PAGE 34 E25
PAGE 28 H38
PAGE 30 H40
PAGE 22 HS25
PAGE 24 HS35
PAGE 26 HS45
PAGE 32 HS20
PAGE 33 HS22
PAGE 35 M58
PAGE 51 ES25
PAGE 51 ES20
72,000
ABZC
18,000*
ABZC
18,000*
ABZC
72,000
ABZC
72,000
ABZC
2048
ABZC
80,000
ABZC
8192
1024
2540
80,000
2048
1024
ABZC
ABZC
ABZC
ABZC
ABZC
ABZC
Sealing
(Max)
IP53
IP66
IP66
IP43
IP43
IP66
IP66
IP52
IP65
IP65
IP64
IP52
IP67
IP67+
IP67+
Output
Type
DLD
OC
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
DLD
5V Reg
DLD
OC
5V Reg
DLD
OC
5V Reg
Diameter
Mounts
Hazardous
Rating Options
1.5"
2.0"
2.5 "
2.5 "
Servo
Face
Square Flange
Servo
Face
Square Flange
Servo
Face
Servo
Face
2.5 "
Face
CSA
CENELEC/ATEX
UL/cUL
CSA
CENELEC/ATEX
UL/cUL
UL/cUL
CENELEC/ATEX
UL/cUL
CENELEC/ATEX
3.75"
Square Flange
4.0" Sq.
Foot Mount
Face
Explosion Proof CL I, II
CENELEC/ATEX
UL/cUL, MSHA
Explosion Proof CL I
UL/cUL
2.5"
3.5"
4.7"
2.0"
2.2"
58mm
2.5"
2.0"
Shaft Mount
with Tether
CENELEC/ATEX
UL/cUL
Shaft Mount
with Tether
CENELEC/ATEX
UL/cUL
Shaft Mount
with Tether
CENELEC/ATEX
UL/cUL
Shaft Mount
with Tether
CENELEC/ATEX
UL/cUL
Shaft Mount
with Tether
Pilot Flange
Servo
Square Flange
Servo
Face
Square Flange
Servo
Face
CSA
CENELEC/ATEX
UL/cUL
CSA
CENELEC/ATEX
UL/cUL
* For higher resolution options, see H25.
KEY: DLD = Differential Line Driver, OC = Open Collectors
6 | BEI Industrial Encoders | www.beiied.com