EMS22 Datasheet, PDF (3/8 Pages) Bourns Electronic Solutions – Non-Contacting Magnetic Encoder

EMS22 Output Waveforms
Quadrature: This output waveform is the
most common among all contacting and non-
contacting encoders. Quadrature, also known as
2-bit quadrature or incremental, is often used to
determine magnitude (count) and direction (up/
down) by an external interface circuit. EMS22
comes equipped with such capability; an external
interface circuit is not required. It also offers an
indexed output with an adjustable width of one or
three times the absolute position value that can be
used for counting the shaft rotation.
Direction/Step: This output is very similar to the
quadrature waveform but offers up to 512 PPR, as
opposed to 256 PPR in quadrature. This output can
be used in incremental counting applications where
a better resolution is desired. Indexing output is also
available with a Direction/Step output waveform.
Absolute: Absolute output refers to the absolute
angular position. This type of output is especially
useful for applications where the absolute position
of a device, such as a camera, is necessary to locate
an object. Also with 1024 distinct angular positions,
the EMS22 offers very high resolution indexing at
every 0.35 °. This type of output code is not affected
by a power outage to the encoder since each angular
position of the encoder has a unique code.
PWM: Pulse-Width Modulation is another form
of absolute waveform that utilizes the square wave
output generated by the sensor to control the
duty cycle of the output at different desired shaft
positions. The EMS22 encoder can generate pulse
widths as low as 1 µs, and as high as 1024 µs in a
complete signal period of 1025 µs. Some advantages
of using this output waveform over other output
types include immunity to noise and faster data
acquisition.
Figure 2: AS5040 ASSP in Two Different States