Construction and design

The resilient encoder housing with a standard flange size of 58 mm is made of anodised aluminium and can be supplied alternatively in stainless steel.
The double-bearing encoder shaft forms a robust mechanical unit with the metal code disc. The multiturn variant operates with a mechanical gear.
A uniform temperature coefficient on all rotating components ensures the temperature behaviour of the absolute rotary
encoder is stable over the long-term.

Sensing principle

The GEL 2352 is based on contactless magnetic scanning of a ferromagnetic steel code disc, the so-called contour
disc. Magnetoresistive (MR) sensors scan three tracks, delivering corresponding sinusoidal signals. The phase position of the three sinusoidal signals is unambiguous within a single turn. The phase position is evaluated on the Vernier principle, providing the absolute position with high resolution and accuracy.

Interfaces

The absolute rotary encoder supplies the position values either in binary or gray code via a fast synchronous serial interface (SSI) or as per encoder profile DS406 via a CANopen interface.

Temperature ranges

High precision SMD components are used in the absolute rotary encoder. Despite careful selection, thermal ageing of
these components cannot be excluded. For this reason the encoder should be stored at a temperature from -40 °C to
+85 °C.
Operating temperatures of -40 °C to +105 °C are allowed, an installed absolute rotary encoder is not allowed to exceed this temperature range. The function of the absolute rotary encoder is ensured within the operating temperature range allowed, (DIN 32878); here it is the temperature at the en-
coder housing that applies.
The temperature of the absolute rotary encoder is affected by the installation situation (thermal conductance, thermal
radiation), the heating caused by the absolute rotary encoder (bearing friction, electrical power loss) and the ambient
temperature. The operating temperature may be higher than the ambient temperature depending on the operation of the absolute rotary encoder.
Depending on the supply voltage the heating caused by the encoder can be up to 10 °C. At high operating speeds
> 5,000 min-1 the heating caused by the encoder can be up to 20 °C due to the bearing friction. If the absolute rotary encoder is operated close to the limits of the specifications allowed, the ambient temperature must
be reduced by suitable means (cooling) such that the operating temperature range allowed is not exceeded.

Technical Data

Dimensional drawings GEL 2352 - SSI (single turn)

Dimensional drawings GEL 2352 - CANopen

The synchronous serial interface transfers the position data
at a clock frequency of up to 2 MHz. Prior to further position
sampling, a minimum clock pulse space of 16 μs must be
met.

Principle of the serial data transmission [gray code (25 bits),

RS 422 / RS 485 standard]
f  62.5 kHz 
T   Length of the clock signal period (= 1/clock frequency)
Tp Clock pulse space, between the clock sequences TP At least 16 μs

Cable length

With the synchronous serial interface protocol the transmis-
sion rate allowed drops with increasing cable length. A
screened, twisted pair cable is recommended for the signal
cables (± CLOCK and ± DATA).

Direction of rotation

The encoder can output increasing position values on the
clockwise or counter clockwise rotation of the shaft. The di-
rection of rotation can be selected by using the CW/CCW
input (counting direction).

PRESET function

The output signals can be set to a PRESET value from any
position. As supplied the encoder is set to half the maximum
resolution. The PRESET is set electronically if the supply
voltage VS is briefly t > 100 ms applied to the PRESET input
(do NOT apply continuously). Other PRESET values are
available on request.

pin	signal	Description
1	GND	Earth
2	Preset	Electronic adjustment VS, t > 100 ms
3	DATA-	Output: Differential data signal in accordance with RS 485
4	DATA+
5	CLOCK-	Input: Differential clock signal in accordance withRS 485
6	CLOCK+
7	VS	Opreating voltage
8	CW/CCW	Direction of rotation: Default = GND; Inverse =VS

M12 connector, 8-pin

Output code	bionar7y Gray
Driver	RS 486 compatible
Clock frequency	max. 2 MHz
Transmission	Max. 1,200 m depending on transmission rate
The immunity to interference	high immunity to interference via symmetrical transmission
Direction of rotation	adjustable, standard clockwise (CW) with view on the en- coder shaft, increasing position values
The immunity to interference	high immunity to interference via symmetrical transmission
The immunity to interference	high immunity to interference via symmetrical transmission

Pin layout - CANopen

pin	Bus IN	Bus OUT
1	CAN_GND	CAN_GND
2	+VS IN	+VS OUT
3	GND	GND
4	CAN_H	CAN_H
5	CAN_L	CAN_L

M12 connector A-coded

Technical data CANopen

Customer-specific designs

Restriction of the type code for SSI

Restriction of the type code for CANopen interface

Ordering overview for mounting accessories

Ordering overview for connection accessories