EMS22 Datasheet, PDF (6/8 Pages) Bourns Electronic Solutions – Non-Contacting Magnetic Encoder

EMS22 Features and Benefits
Design engineers with constraints such as cost, space,
circuit complexity and resolution will appreciate the
unique features and benefits of the Model EMS22.
EMS22 non-contacting rotary magnetic encoders can be
interconnected in a daisy-chain configuration for a serial
read-out option. This option is beneficial where memory
overhead and space for wiring each individual encoder
separately is critical in the construction of a control device
as illustrated in Figure 5. The output of this configuration
is the combined output of each individual encoder
connected in series to the microprocessor.
Another great capability of this product is the chip-select
option. This option allows the interrogation of each encoder
individually by the microprocessor. Unlike daisy-chain, this
feature takes less time to execute, ultimately enhancing the
speed of the control loop response.
If temperature variation is a critical factor in the application,
the EMS22 offers excellent performance in a wide
temperature range, from - 40 °C to + 125 °C (- 40 °F to
+ 257 °F). This feature is suitable for applications in extremely
cold and hot temperature conditions that can affect the
output performance of optical and contacting encoders.
Micro-
processor
Data Input
EMS22
Data
Input
Prog.
Data
Input
Chip
Select CLK
EMS22
Data
Input
Prog.
Data
Input
Chip
Select CLK
CLK
Chip Select
Figure 5: Daisy-Chain Hardware Configuration
EMS22
Data
Input
Prog.
Data
Input
Chip
Select CLK
Designers can choose from a variety of output signals to
fit their application needs, whether it is a simple counter,
or precision sensing. The EMS22 is capable of operating
with either a +5.0 Vdc supply voltage, or the more energy
efficient +3.3 Vdc supply voltage.
Table 1 below provides a comparison of the various
technologies, output types, supply voltages, and resolution
that can be achieved with each Bourns® Encoder model
family.
Bourns®
Encoder Model
EAW (ACE)
ECW
EM14
Technology
Contacting
Contacting
Optical
Output Type(s)
Absolute
Quadrature
Quadrature
EN
Optical
Quadrature
EMS22
EMS22
EMS22
Magnetic
Magnetic
Magnetic
Quadrature
Direction/Step
Absolute/PWM
Table 1: Comparison of Various Bourns® Models
Supply Voltage
(Vdc)
3.3 & 5.0
3.3 & 5.0
5.0
5.0
3.3 & 5.0
3.3 & 5.0
3.3 & 5.0
Resolution
(PPR)/ States*
128*
6, 9, 12, 24, 36
8, 16, 32, 64
25, 50, 64, 100, 125, 128,
200, 256
32, 64, 128, 256
64, 128, 256, 512
1024*