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.

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.

Figure 5: Daisy-Chain Hardware Configuration

Table 1: Comparison of Various Bourns® Models

Micro-

processor

Data Input

CLK

Chip Select

Data

Input

Chip

Select CLK

Prog.

Data

Input

EMS22

Data

Input

Chip

Select CLK

Prog.

Data

Input

EMS22

Data

Input

Chip

Select CLK

Prog.

Data

Input

EMS22

Bourns®

Encoder Model

Technology

Output Type(s)

Supply Voltage

(Vdc)

Resolution

(PPR)/ States*

EAW (ACE)

Contacting

Absolute

3.3 & 5.0

128*

ECW

Contacting

Quadrature

3.3 & 5.0

6, 9, 12, 24, 36

EM14

Optical

Quadrature

5.0

8, 16, 32, 64

EN

Optical

Quadrature

5.0

25, 50, 64, 100, 125, 128,

200, 256

EMS22

Magnetic

Quadrature

3.3 & 5.0

32, 64, 128, 256

EMS22

Magnetic

Direction/Step

3.3 & 5.0

64, 128, 256, 512

EMS22

Magnetic

Absolute/PWM

3.3 & 5.0

1024*