We will be closed for the holidays from Friday, December 20th, 2024 through Sunday, January 5th, 2025.
Our offices reopen Monday, January 6th, 2025 at 6:30 AM Pacific Time.
Thank you for your continued business and we look forward to serving you in the new year!

EM1 Transmissive Optical Encoder Module

EM1 Features

  • Two-channel quadrature with optional index
  • Improved replacement for HEDS-9000 Series
  • Single 5 VDC supply
  • Resolutions from 32 to 2,500 CPR
  • Internal decoupling capacitor
  • Sink/source 8mA outputs

See more info below

Configure the EM1

EM1 Product Description

Restriction of Hazardous Substances

The EM1 is a transmissive optical encoder module designed to detect rotary or linear position when paired together with an encoder disk or linear strip. The EM1 consists of a lensed LED source and a monolithic detector IC enclosed in a small polymer package. The EM1 uses phased array detector technology to provide superior performance and greater tolerances over traditional aperture mask-type encoders.

The EM1 provides digital A & B quadrature outputs with an optional third output index channel. Each EM1 module is resolution-specific and is matched to the resolution of an encoder disk or linear strip. The EM1 module now supports all standard resolutions offered by the HEDS-9000 series encoder module and additional resolutions. The EM1 operates with a single 5V supply and provides single-ended outputs capable of sinking and sourcing 8mA. An internal 0.1 µF decoupling capacitor is designed into the EM1 to provide enhanced noise immunity over the HEDS-9000 series encoder modules.

For open collector and higher voltage applications, add the PC3 cable driver, or for differential cable driver outputs, add the PC4 cable driver. Encoder disks, linear strips, quadrature decoder chips, counter chips, computer interface boards, mating connectors, and cables are also available.

Product Specifications

COMPATIBLE 1" & 2" DISKS

  1" DISKS
CPR MODULE
Non-Index		 1" DISK
Non-Index		 MODULE
Index		 1" DISK
Index
32 EM1-1-32-N DISK-1-32-*-NE    
50 EM1-1-50-N DISK-1-50-*-NE EM1-1-50-I DISK-1-50-*-IE
96 EM1-1-100-N DISK-1-96-*-NE EM1-1-100-I DISK-1-96-*-IE
100 EM1-1-100-N DISK-1-100-*-NE EM1-1-100-I DISK-1-100-*-IE
120 EM1-1-100-N DISK-1-120-*-NE    
192 EM1-1-200-N DISK-1-192-*-NE EM1-1-200-I DISK-1-192-*-IE
200 EM1-1-200-N DISK-1-200-*-NE EM1-1-200-I DISK-1-200-*-IE
250 EM1-1-250-N DISK-1-250-*-NE EM1-1-250-I DISK-1-250-*-IE
256 EM1-1-250-N DISK-1-256-*-NE EM1-1-250-I DISK-1-256-*-IE
360 EM1-1-360-N DISK-1-360-*-NE EM1-1-360-I DISK-1-360-*-IE
400 EM1-1-400-N DISK-1-400-*-NE EM1-1-400-I DISK-1-400-*-IE
500 EM1-1-500-N DISK-1-500-*-NE EM1-1-500-I DISK-1-500-*-IE
512 EM1-1-512-N DISK-1-512-*-NE EM1-1-512-I DISK-1-512-*-IE
540 EM1-1-540-N DISK-1-540-*-NE EM1-1-540-I DISK-1-540-*-IE
720 EM1-1-720-N DISK-1-720-*-NE EM1-1-720-I DISK-1-720-*-IE
800 EM1-1-800-N DISK-1-800-*-NE EM1-1-800-I DISK-1-800-*-IE
900 EM1-1-900-N DISK-1-900-*-NE EM1-1-900-I DISK-1-900-*-IE
1000 EM1-1-1000-N DISK-1-1000-*-NE EM1-1-1000-I DISK-1-1000-*-IE
1024 EM1-1-1024-N DISK-1-1024-*-NE EM1-1-1024-I DISK-1-1024-*-IE
1250 EM1-1-1250-N DISK-1-1250-*-NE EM1-1-1250-I DISK-1-1250-*-IE
  *Represents the bore size    
  2" DISKS
CPR MODULE
Non-Index		 2" DISK
Non-Index		 MODULE
Index		 2" DISK
Index
64 EM1-1-32-N DISK-2-64-*-NE    
100 EM1-1-50-N DISK-2-100-*-NE EM1-1-50-I DISK-2-100-*-IE
200 EM1-1-100-N DISK-2-200-*-NE EM1-1-100-I DISK-2-200-*-IE
400 EM1-1-200-N DISK-2-400-*-NE EM1-1-200-I DISK-2-400-*-IE
500 EM1-2-500-N DISK-2-500-*-NE EM1-2-500-I DISK-2-500-*-IE
800 EM1-1-400-N DISK-2-800-*-NE EM1-1-400-I DISK-2-800-*-IE
1000 EM1-2-1000-N DISK-2-1000-*-NE EM1-2-1000-I DISK-2-1000-*-IE
1024 EM1-2-1024-N DISK-2-1024-*-NE EM1-2-1024-I DISK-2-1024-*-IE
1800 EM1-2-1800-N DISK-2-1800-*-NE EM1-2-1800-I DISK-2-1800-*-IE
2000 EM1-2-2000-N DISK-2-2000-*-NE EM1-2-2000-I DISK-2-2000-*-IE
2048 EM1-2-2048-N DISK-2-2048-*-NE EM1-2-2048-I DISK-2-2048-*-IE
2500 EM1-2-2500-N DISK-2-2500-*-NE EM1-2-2500-I DISK-2-2500-*-IE
  *Represents the bore size    

COMPATIBLE 1" & 2" HUBDISKS

  1" HUBDISKS
CPR MODULE
Non-Index		 1" HUBDISK
Non-Index		 MODULE
Index		 1" HUBDISK
Index
32 EM1-1-32-N HUBDISK-1-32-*-NE    
50 EM1-1-50-N HUBDISK-1-50-*-NE EM1-1-50-I HUBDISK-1-50-*-IE
96 EM1-1-100-N HUBDISK-1-96-*-NE EM1-1-100-I HUBDISK-1-96-*-IE
100 EM1-1-100-N HUBDISK-1-100-*-NE EM1-1-100-I HUBDISK-1-100-*-IE
120 EM1-1-100-N HUBDISK-1-120-*-NE    
192 EM1-1-200-N HUBDISK-1-192-*-NE EM1-1-200-I HUBDISK-1-192-*-IE
200 EM1-1-200-N HUBDISK-1-200-*-NE EM1-1-200-I HUBDISK-1-200-*-IE
250 EM1-1-250-N HUBDISK-1-250-*-NE EM1-1-250-I HUBDISK-1-250-*-IE
256 EM1-1-250-N HUBDISK-1-256-*-NE EM1-1-250-I HUBDISK-1-256-*-IE
360 EM1-1-360-N HUBDISK-1-360-*-NE EM1-1-360-I HUBDISK-1-360-*-IE
400 EM1-1-400-N HUBDISK-1-400-*-NE EM1-1-400-I HUBDISK-1-400-*-IE
500 EM1-1-500-N HUBDISK-1-500-*-NE EM1-1-500-I HUBDISK-1-500-*-IE
512 EM1-1-512-N HUBDISK-1-512-*-NE EM1-1-512-I HUBDISK-1-512-*-IE
540 EM1-1-540-N HUBDISK-1-540-*-NE EM1-1-540-I HUBDISK-1-540-*-IE
720 EM1-1-720-N HUBDISK-1-720-*-NE EM1-1-720-I HUBDISK-1-720-*-IE
800 EM1-1-800-N HUBDISK-1-800-*-NE EM1-1-800-I HUBDISK-1-800-*-IE
900 EM1-1-900-N HUBDISK-1-900-*-NE EM1-1-900-I HUBDISK-1-900-*-IE
1000 EM1-1-1000-N HUBDISK-1-1000-*-NE EM1-1-1000-I HUBDISK-1-1000-*-IE
1024 EM1-1-1024-N HUBDISK-1-1024-*-NE EM1-1-1024-I HUBDISK-1-1024-*-IE
1250 EM1-1-1250-N HUBDISK-1-1250-*-NE EM1-1-1250-I HUBDISK-1-1250-*-IE
  *Represents the bore size    
  2" HUBDISKS
CPR MODULE
Non-Index		 2" HUBDISK
Non-Index		 MODULE
Index		 2" HUBDISK
Index
64 EM1-1-32-N HUBDISK-2-64-*-NE    
100 EM1-1-50-N HUBDISK-2-100-*-NE EM1-1-50-I HUBDISK-2-100-*-IE
200 EM1-1-100-N HUBDISK-2-200-*-NE EM1-1-100-I HUBDISK-2-200-*-IE
400 EM1-1-200-N HUBDISK-2-400-*-NE EM1-1-200-I HUBDISK-2-400-*-IE
500 EM1-2-500-N HUBDISK-2-500-*-NE EM1-2-500-I HUBDISK-2-500-*-IE
800 EM1-1-400-N HUBDISK-2-800-*-NE EM1-1-400-I HUBDISK-2-800-*-IE
1000 EM1-2-1000-N HUBDISK-2-1000-*-NE EM1-2-1000-I HUBDISK-2-1000-*-IE
1024 EM1-2-1024-N HUBDISK-2-1024-*-NE EM1-2-1024-I HUBDISK-2-1024-*-IE
1800 EM1-2-1800-N HUBDISK-2-1800-*-NE EM1-2-1800-I HUBDISK-2-1800-*-IE
2000 EM1-2-2000-N HUBDISK-2-2000-*-NE EM1-2-2000-I HUBDISK-2-2000-*-IE
2048 EM1-2-2048-N HUBDISK-2-2048-*-NE EM1-2-2048-I HUBDISK-2-2048-*-IE
2500 EM1-2-2500-N HUBDISK-2-2500-*-NE EM1-2-2500-I HUBDISK-2-2500-*-IE
  *Represents the bore size    

COMPATIBLE LINEAR STRIPS

LPI MODULE
Non-Index		 Linear Strip
Non-Index		 MODULE
Index		 Linear Strip
Index
120 EM1-0-120-N LIN-120-*-N EM1-0-120-I LIN-120-*-#
127 EM1-0-127-N LIN-127-*-N EM1-0-127-I LIN-127-*-#
150 EM1-0-150-N LIN-150-*-N EM1-0-150-I LIN-150-*-#
180 EM1-0-180-N LIN-180-*-N EM1-0-180-I LIN-180-*-#
200 EM1-0-200-N LIN-200-*-N EM1-0-200-I LIN-200-*-#
250 EM1-0-250-N LIN-250-*-N EM1-0-250-I LIN-250-*-#
300 EM1-0-300-N LIN-300-*-N EM1-0-300-I LIN-300-*-#
360 EM1-0-360-N LIN-360-*-N EM1-0-360-I LIN-360-*-#
500 EM1-0-500-N LIN-500-*-N EM1-0-500-I LIN-500-*-#
  * Represents length of Linear Strip * Represents length of Linear Strip
# Represents location of Index

ENVIRONMENTAL

Parameter Value Units
Operating Temperature -40 to 100 C
Electrostatic Discharge, IEC 61000-4-2 ± 4 kV
Vibration (10Hz to 2kHz, sinusoidal) 20 G
Shock (6 milliseconds, half-sine) 75 G

OPERATING CONDITIONS

PARAMETER MIN.  MAX. UNITS
A/B Output Frequency 0 300 kHz
Disk RPM 0 (18 x 10^6) / CPR RPM
Linear Strip Speed 0 (3 x 10^5) / LPI inches/sec.
Disk/Linear Strip Radial Position Tolerance ±.005      inch

ELECTRICAL SPECIFICATIONS

  • Specifications apply over the entire operating temperature range.
  • Typical values are specified at Vcc = 5.0V and 25C.
PARAMETER MIN. TYP. MAX. UNITS CONDITIONS
Supply Voltage 4.5 5.0 5.5 V Ripple < 100 mVpp
Supply Current, EM1-0- (linear strip)   27 33 mA LPI < 300, no load
  54 65 mA LPI ≥ 300, no load
Supply Current, EM1-1- (1" disk)   27 33 mA CPR < 500, no load 
  54 65 mA CPR ≥ 500, no load
Supply Current, EM1-2- (2" disk)   27 33 mA CPR < 1000, no load 
  54  65 mA CPR ≥ 1000, no load 
Low-level Output     0.5 V IOL = 8mA max.
  0.05   V No load
High-level Output 2.0     V IOH = -8mA max.
  4.8   V No load
Output Current Per Channel -8   8 mA  
Load Capacitance      100  pF  
Output Rise Time   110   nS  
Output Fall Time   100   nS  

TIMING CHARACTERISTICS

ENCODING CHARACTERISTICS:

  • Specifications apply over the entire operating temperature range.
  • Values are for the worst error over full rotation.
  • Refer to the timing diagram below.
PARAMETER SYMBOL MIN. TYP. MAX. UNITS
Symmetry X, Y 150 180 210 °e
Quadrature  Z 60 90 120 °e
Index Pulse Width Po 40 90 120 °e
Ch. I Rise After Ch. B or Ch. A Fall t1 50 100 200 ns
Ch. I Fall After Ch. B or Ch. A Rise t2 -10 15 25 ns

TIMING DIAGRAM:

CPR: The number of Cycles (C) of the A or B outputs Per Revolution.

Cycle Error: 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/CPR of a revolution.

Index (I): The index output goes high once per revolution, coincident with the low states of channels A and B, nominally 1/4 of one cycle (90 °e).

LPI: Lines Per Inch. The number of Cycles (C) of the A or B output per inch of linear strip movement.

One Shaft Rotation: 360 mechanical degrees.

One Electrical Degree (°e): 1/360th of one cycle.

One Cycle (C): 360 electrical degrees (°e). Each cycle can be decoded into 1 or 4 states, referred to as X1 or X4 resolution multiplication.

PPR: The number of resolvable Positions Per Revolution of the encoder disk with x4 quadrature decoding.

Quadrature (Z): The phase lag or lead between channels A and B in electrical degrees, nominally 90 °e.

Symmetry: A measure of the relationship between (X) and (Y) in electrical degrees, nominally 180°e.

INSTALLATION TORQUE

PARAMETER TORQUE
Mounting Screws 3.5-4 in-lbs

EM1 / HEDS COMPARISON

US Digital is the designer and manufacturer of the EM1 transmissive optical encoder module. The design of the EM1 provides electrical and mechanical compatibility with HEDS-9000, HEDS-9100, HEDS-9200, HEDS-9040, and HEDS-9140 series modules.

The process of switching from the HEDS to the EM1 module should not require any mechanical or electrical changes. Simply use the EM1 and matching codewheel in place of the HEDS module and codewheel. The EM1 has a built-in index channel available on most resolutions, for both rotary disks and linear strips. The EM1 uses a US Digital designed codewheel with 2 tracks rather than 3 tracks for index versions. The EM1 offers improved output drive capability and will source and sink 8mA at TTL levels. 

Physically, the EM1 has no external wire loops which can interfere when mounting. The connector pins are 0.051" shorter than HEDS modules, while still providing .30" insertion depth. US Digital's EM1 offers custom resolutions.

PIN-OUTS

Pin Description
1 Ground
2 Index
3 A channel
4 +5VDC power
5 B channel

PRODUCT CHANGE NOTIFICATIONS

Title Date Description Download
EM1 LED Die - PCN 1016 2/7/2013 As part of US Digital's continual assurance of supply strategy, we have qualified additional sources for our LED die used in our EM1 encoder module, which in turn impacts all of the following products:

EM1, E2, E3, E5, E6, H1, H15, H3, H5, H6, HB5M, HB6M, HD25, PE, S1, S2, S5, S6, T5 and T6

The device specification will remain the same, i.e. there will be no change to form, fit or function of the product(s) as specified by US Digital. The appropriate quality and reliability testing has been performed on representative products to ensure normal parametric distribution, consistent with US Digital's quality and reliability standards.		 Download
EM1 & EM2 Update - PCN 4199 1/14/2014 Based on our continuous process improvement program, US Digital is changing the current marking method for our EM1 and EM2 encoder modules to a serialization method. This change will allow for each module to have a unique code; the current marking method is based on a date code system that includes all encoder modules produced within a specific week / year. The serialization system will be based on a hexadecimal system. Download

Additional Information

Product Notes

  • US Digital® warrants its products against defects in materials and workmanship for two years. See complete warranty for details.

Datasheets

Related

Press Releases

3D Model Downloads

Please configure your product first to download a 3D model.
(Note: The formats below will become links if there are 3D models available.)

    • SolidWorks Format
    • IGES Format
    • Parasolid Format
    • STEP Format

    Product Configurator

    For pricing, this product requires configuration.

    Begin by completing either Option 1 or 2 below. Questions? Contact our support team.

    Option 1: Configure the Product

    Use the configuration tool to provide information regarding your product needs. Not sure what to do or need additional assistance? Our support team is here to help.

    We recommend enabling Javascript when using the product configurator.

    Option 2: Enter the Product Part Number Directly

    If you know your product part number, enter it in the following field. The part number format looks something like this: E5-5000-394-IE-S-D-D-3...

    Our products are not currently available for direct online purchase. To place an order please contact us directly with your part number.

    For purchasing or volume discounts, please configure the part above, then use the completed part number and contact us!

    Feedback

    US Digital's mission is a commitment to quality and constant improvement. If you find an error to a product on this page, please let us know!

    Compare Items (Max 3):