Product Features; Functional Principle - ELGO Electronic EMAX-RO Series Operation Manual

3 Product Features

The angle measuring system EMAX-RO is a combination of a sensor and a mag-
netic ring. The magnetic ring is mounted directly to an engine shaft or an axle
(see mounting suggestions  5.3). This ensures a quick and easy installation.
EMAX-RO is especially suited for measuring rotative angles.
The sensor head with high protection class is resistant against any kind of dust
and dirt and works completely without wear. Furthermore, the rotative measuring
system EMAX-RO has the advantage of absolute measurement and therefore
belongs in the category of single turn encoders.
Important features:
Rotative angle measuring system

Resolution of 16000 measuring steps over 360° (other resolutions on request)

Absolute measurement

Different interfaces are available

Absolute:
- Standardly: SSI or CANopen DS406;
- On request: RS422, addressable RS422, RS232, CAN BASIC ELGO
- In preparation: BISS-C
Incremental:
- 90° phase shifted square-wave signals TTL or HTL
- Sine/cosine signal 1Vss
Direct measurement on engine shaft or axle possible

3.1

Functional principle

A Hall sensor and a magneto-resistive impedance measuring bridge are guided over a two-track magnetic tape
with a fine-interpolation trace and an absolute trace. Together with the sensor line the absolute track provides
an absolute value and the fine-interpolation trace provides together with the interpolation electronic the measur-
ing systems high resolution. The figure shows two magnetic traces, with North Pole and South Pole magnetiza-
tion. The fine interpolation trace encloses alternately north and South Pole traces with a distance of 5 mm, these
are scanned with resistance bridges and provide a resolution of 16000 steps per turn. The absolute value pro-
vides the sensor line with 16 single Hall sensors. These sensors are scanning the code sections of the north and
south poles. The absolute value on the magnetic ring repeats once per revolution.
For easier illustration were the tracks of the magnetic ring shown as a tape
S N S N S
N S N S N S N
Figure 1: Functional principle
N
S N
S N S
S N S N S N S N
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Product Features
N S
Absolut track
Non magnetized track
S N S
Fine interpolation track