1. DS-25 Data Sheet , V 2.0b ,June 2013
DS-25
Absolute position, rotary Electric Encoder™
The DS-25 is a member of the DS series of Electric Encoders,
based on Netzer Precision proprietary technology. These
encoders offer many advantages, some unparalleled:
Low profile (8 mm).
Hollow, floating shaft.
No bearings or other contacting elements.
High precision.
High tolerance to temperature, shock, moisture, EMI & RFI.
Insensitive to magnetic fields.
Very low weight.
The DS-25 is suited to demanding application such as: aerospace,
medical, instrumentation, automation, etc.
The holistic
structure
of the Electric Encoder™
provides generous mounting tolerance, thus
obviating the need for internal ball bearings.
The lack of bearings and components
such as flexible couplers, glass disc,
light sources and detectors, along with
very low power consumption makes
the DS-25 encoder virtually failure free.
The internally shielded, DC operated Electric
Encoder™ includes an electric field generator,
a field receiver, a sinusoidal shaped
dielectric rotor, and processing electronics.
The outputs signals of DS-25 Electric Encoder™
are analog Sine / Cosine representing the
rotation angle, incremental or absolute position.
Mechanical
Allowable mounting eccentricity (operational) ±0.1 mm
Allowable rotor axial motion (operational) ±0.1 mm
Rotor inertia 11.13 gr · mm2
Total weight 4gr
Outer diameter / Inner diameter / Profile 25/6/7mm
Material (stator, rotor) Ultem™ polymer
Material mounting clamps , M2 Ultem™
Electrical
Supply voltage 5V ± 5%
Interconnection Ø 3.5 mm Shielded cable
Environment
EMC IEC 6100-6-2, IEC 6100-6-4
Operating temperature range -40°C to +85°C
Relative humidity <98 % - non condensing
Shock endurance IEC 60068-2-27
100 g for 11 ms
Vibration endurance IEC 60068-2-6
20 g 10 – 2000 Hz
Protection IP 40
Performance
Electrical Cycles – Fine/Coarse channels 16 / 3
Angular resolution (using 12 bit A/D conversion) 17 bits
Static error (with offset compensation) < 15 mDeg (0.262mrad)
Maximum operational speed 1,500 rpm
Measurement range Unlimited rotation
Output SSi absolute position
BIT (build in tests , optional) Included (SSi version)
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2. Digital - SSi Interface (absolute position)
DS-25
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Synchronous Serial Interface (SSi) allows for serial transmission
of absolute position data from the Electric Encoder™
responding to controller clock pulses. The Encoder and
controller are linked by clock and data differential signal lines.
n n - 1 1 0
- 2 -
Output signal parameters
Signal latency ~250 μSec
Output code Binary
Serial output SSi Differential RS-422
Clock SSi Differential RS-422
Monoflop time 25 μSec
Clock Frequency 0.5 ÷ 2.5 MHz
Position update (Max) 30 KHz
Electrical parameters
Current consumption ~ 180 mA
SSi - Wires color code
# Name Color Function
1 Clock + Grey
SSi Clock
2 Clock - Blue
3 Data - Yellow
SSi Data
4 Data + Green
5 GND Black Ground
6 +5V Red Power supply
t1 T
n * T
t3
Clock
t2 MSB
LSB
Data
Monoflop
Recommendations
n total number of data bits
T clock period (sec) user defined
1/T clock frequency 0.5 ÷ 2.5 MHz (user defined) 2.5 MHZ
t1
minimum time required for the encoder to freeze data and preset
the shift registers before receiving the first rising edge to prompt the MSB
T/2
t2 data transmission delay (increases with cable length) “0” on standard cable length
t3 equired delay to refresh position data between subsequent position >25usec
3. Digital - SSi Interface (absolute position)
DS-25
Software tools:
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Advanced calibration and monitoring options available by using the Electric Encoder Explorer software ( factory
supplied ) using the NCP (Netzer Communication Protocol) , the Encoder Explorer enables:
- 3 -
ELECTROMATE
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sales@electromate.com
4. Analog - Sine / Cosine , 1 Vp-p interface
DS-25
- 4 -
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Wires color code
# Name Color Function
1 GND Black Ground
2 C/F Grey Coarse / Fine
3 Sine Blue Sine signal
4 Vr Green V reference
5 Cosine Yellow Cosine signal
6 +5V Red Power supply
Output signal parameters
Signal latency 250 μSec
Fine-mode output noise (DC to 1kHz) 100 μV (p-p)
Fine-mode output amplitude 0.5V ± 20%
Coarse-mode output amplitude 0.5V ± 20%
Phase relationship (CW shaft rotation - seen from top) Sine leads Cosine
Signal bandwidth DC to 1 kHz
Coarse and Fine channels
The DS-25 has two operation modes:
a Coarse-mode and a Fine-mode -
equivalent to two separate encoders
in a common housing. The modes are
selectable by a logic C/F command; logic
“0” (0V to +0.5V) selects the Coarse-mode,
which has 3 Electrical Cycle/Revolution
(EC/R) while logic ”1” (+3V to +5V) selects
the Fine-mode which has 16 EC/R. The
switching time is less than 1 ms.
The Coarse-mode outputs need to be read
only upon system initiation after which
the encoder is permanently switched to
the Fine mode. Coarse and Fine sine/
cosine pairs are used to calculate the initial
absolute position, from that point tracking
the Fine-channel outputs provides the
absolute mechanical rotation angle with the
specified accuracy and resolution.
All output signals are referenced to an
internally generated voltage Vr (~2.25V)
Absolute Position calculation:
The analog Sine /Cosine outputs convey the electric angle of the Coarse or Fine signals. The absolute
mechanical angle is computed by digitizing the analog signals and applying factory-supplied
algorithms. Please refer to AN-02 and AN-03 .
5. - 5 -
DS-25
DS
Product line
OD mm
Outputs:
D - Digital : SSi (external module)
C - AqB +I (external module)
0 - Analog
- n n n
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Interconnection:
0 - Loose wires 250 mm
S - Shielded cable
C -Capsulated external module
Resolution Binary
Code Bit CPR
D 15 32,768
E 16 65,536
F 17 131,072
DS - 25 - 16 - D- - S
Fine EC/R
F 0
0 - flying leads
C- connector
Analog
Code 0
Ordering
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6. Sold & Serviced By:
250 mm 250 mm
- 6 -
Interconnection options
DS-25
SC2SSi external module
250 mm 250 mm
SC2SSi external capsulated module
250 mm
AWG30 shielded cable
250 mm
AWG30 shielded cable
AWG32 Teflon isolated
AWG30 shielded cable
AWG30 shielded cable AWG30 shielded cable
Digital SSi Analog
30 AWG twisted pairs (3)
Braided shield
Jacket 0.45mm
Ø 3.45 ± 0.20
Netzer Cat No.: CB00014 , 30 AWG twisted pair (3) :
2 (30 AWG 25/44 tinned copper , 0.15 PFE to Ø0.6 ± 0.05 ).
Cable: Three 30 AWG twisted pairs.
Shield: Tinned copper braided 95% min. coverage.
Jacket:0.45 silicon rubber to Ø3.45 ±0.2
Pair # Color
1
2
3
Red / Black
Gray / Blue
Green / Yellow
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7. - 7 -
Sold & Serviced By:
ENCODER BOTTOM VIEW
The information contaned in this drawing is the sole property ot Netzer Precision Motion Sensores Ltd. Any reproduction in part or
whole without the written permission of Netzer Precision Motion Sensors Ltd.is prohibited. The drawing is confidential,and is the
property of Netzer Precision Ltd. it must not be disclosed to a third party without written consent of Netzer Precision Ltd
Coating:
Revision :
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TITLE:
MATERIAL:
01 CAT NO. :
.
SIGNATURE
VADIM.D
JACOB N 14.03.13 DS-25 ICD
SCALE: 1:1
A3
SHEET 1 OF 1
DWG NO. :
NAME DATE
DRAWN
CHK'D
APPV'D
UNLESS OTHERWISE SPECIFIED:
DIMENSIONS ARE IN mm
SURFACE FINISH: N6
LINEAR TOLERANCES: 0.1 mm
ANGULAR TOLERANCES: 0.5 deg
ALL CHAMFER: 0.1 mm X 45°
14.03.13
3
6
++
0.06
0.04 A
3 SLOTS FOR ENCODER
CLAMP EQ.SP
ENCODER TOP VIEW
SECTION A-A
SCALE 5 : 1
MAUNTIG SURFACE
0.70
5.60
1.50
- +
25
8
+0.30
7 0
1
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