Netzer Precision VLS-60 Absolute Hollow Shaft Rotary Encoder Kit User Guide

Netzer Precision VLS-60 Absolute Hollow Shaft Rotary Encoder Kit

Specifications

• Product Model: VLS-60
• Type: Absolute Hollow Shaft Rotary Encoder Kit
• Brand: Netzer
• Features: Space-proven COTS solution, compact dimensions, minimal weight, signature Netzer hollow shaft
• Designed for: Demanding applications, space exploration

Product Information

• The VLS-60 Absolute Hollow Shaft Rotary Encoder Kit is designed to meet the requirements of the most demanding applications, particularly in the field of space exploration. It is part of the Netzer VLS product line, known for its space-proven COTS solutions engineered for excellence at affordable prices.
• The encoder features compact dimensions, minimal weight, and the signature Netzer hollow shaft, providing unmatched precision essential for space missions.
• Netzer has a legacy of transforming commercially available components and conventional encoders for space applications, accumulating unique expertise through successful missions. The VLS range is designed to meet rigorous demands such as Total Ionizing Dose (TID) and minimal outgassing, crucial for surviving the harsh space environment.

Product Usage Instructions

Mechanical Mounting
Follow the End-of-Shaft Installation guide provided in section 10.1 of the manual for proper encoder mounting.

Operational Mode
Refer to section 14 of the manual for details on operational modes, specifically SSi / BiSS protocols.

FAQ (Frequently Asked Questions)

• What are the key features of the VLS-60 Absolute Hollow Shaft Rotary Encoder Kit?
  The key features include space-proven COTS solution, compact dimensions, minimal weight, and the signature Netzer hollow shaft for precision.

• What applications is the VLS-60 encoder suitable for?
  The VLS-60 encoder is designed for demanding applications, especially in the field of space exploration where precision and reliability are crucial.

VLS Encoders Introduction

• Designed to meet the requirements of the most demanding applications
• Embark on your next LEO project with the unparalleled Netzer VLS product line – the only space-proven COTS solutions engineered for excellence, with affordable prices.
• Our VLS series is designed to elevate your project, featuring compact dimensions, minimal weight, and the signature Netzer hollow shaft for unmatched precision. These characteristics are not just benefits; they’re essentials for the demands of space exploration.
• With a legacy of transforming commercially available components and conventional encoders for the cosmos Netzer has accumulated a unique expertise through numerous successful missions.
• Our commitment to innovation means the VLS range meets the rigorous demands of TID (Total Ionizing Dose) and minimal outgassing – key factors for thriving in the harsh environment of space.
• The VLS encoders are characterized by the following features that sets them apart from other similar encoders:
  • High Precision: < 0.006 degree
  • Low Power Consumption: < 100 mAmp
  • Space Proven Performance: TID (30 Krad) SEE (1E11 p/cm²/s protons @ 200MeV) + Low outgassing
  • Parylene Conformal Coating: Improved Low outgassing (TML<1%, CVCM < 0.1%), reduces Tin Whiskers risk
  • Innovative Hollow Shaft Design
  • Low Profile : < 6 mm
  • Extreme Temperature Durability: (including temp drift compensation)
  • Rigorous Testing & Production: Shock, vibration, and ESS. Thermal vacuum optional
  • Service Life: MTBF 15 years
  • Customizable Reporting
• The holistic structure of the VLS Electric Encoder™ makes it unique. Its output reading is the averaged outcome of the entire circumference area of the rotor. This inherent design characteristic provides the VLS encoder with outstanding precision as well as a tolerant mechanical mounting.
• The absence of components such as ball bearings, flexible couplers, glass discs, light sources & detectors, along with very low power consumption, enables the VLS encoders to deliver virtually failure-free performance.

Technical Specifications

General

Mechanical

Electrical

Environmental

11msec saw-tooth per MIL-810G
Vibration functional| 7.7grms @ 20 to 2000 Hz per MIL-810G Category 24
Protection| Parylene conformal coating: improved low outgassing, reduces Tin Whiskers risk.
Low out-gassing| TML < 1%, CVCM < 0.1%
Radiation tested for| TID = 30KRAD

SEE 11E1 p/cm²/s protons @200MeV

Ordering Code

Mechanical Drawings

Mechanical Interface Control Drawing

Cable options

OD: Ø 0.6 ± 0.05 mm

| 28 AWG 40/44 Tinned copper Insulation: PFA Ø 0.12

OD: Ø 0.64 ± 0.05 mm

Temp. Rating| -55°C to +150°C
Braided shield| Thinned copper braided 95% min. coverage
Jacket| 0.45 silicon rubber (NFA 11-A1)| 0.44 silicon rubber (NFA 11-A1)
Diameter| Ø 3.45 ± 0.16 mm| Ø 3.53 ± 0.16 mm

Storage and Handling

• Storage temperature: -55°C to +125 °C
• Humidity: Up to 98% non-condensing

ESD Protection

As usual for electronic circuits, during product handling do not touch electronic circuits, wires, connectors or sensors without suitable ESD protection. The integrator / operator shall use ESD equipment to avoid the risk of circuit damage.

Product Overview

Overview

• The VLS-60 absolute position Electric Encoder™ is a rotary position sensor developed for demanding Space applications.

• The Electric Encoder™ non-contact technology provides accurate position measurement through the modulation of an electric field.

• The VLS-60 Electric Encoder™ is a kit-encoder, i.e., its rotor and stator are separate.

  1. Encoder stator
  2. Encoder rotor

Unpacking – standard order
The package of the standard VLS-60 contains the encoder Stator & Rotor. Packed in a double vacuum with sealing bag.
Optional accessories:

1. CNV-00003, RS-422 to USB converter (with USB internal 5V power supply path).
2. NanoMIC-KIT-01, RS-422 to USB converter. Setup & Operational modes via SSi /BiSS interface.
3. RJ VLS-60 rotary jig
4. DKIT-VLS-60-SG-S0, Mounted SSi encoder on rotary jig, RS-422 to USB converter and cables.
5. DKIT-VLS-60-IG-S0, Mounted BiSS encoder on rotary jig, RS-422 to USB converter and cables.

Installation flow chart

Electric Encoder Software Installation

The Electric Encoder Explorer (EEE) software:

• Verifies correct mounting for an adequate signal amplitude
• Calibration of offsets
• General set up and signal analysis
  This section describes the steps associated with installing the EEE software application.

Minimum requirements

• Operating system: MS windows 7/ 10, (32 / 64 bit)
• Memory: 4MB minimum
• Communication ports: USB 2
• Windows .NET Framework, V4 minimum

Installing the software

• Run the Electric Encoder™ Explorer file found on Netzer website: Encoder Explorer Software Tools
• After the installation you will see Electric Encoder Explorer software icon on the computer desktop.
• Click on the Electric Encoder Explorer software icon to start.

Mechanical Mounting

Encoder mounting – End-of-Shaft Installation

Typical encoder installation uses

• Mounting screws Socket Head Cup Screw 8xM2, 4 each per stator & rotor.
• Mounting dowel pins 4xØ2, 2 each per stator & rotor (not included with the encoder).

Encoder stator / Rotor relative position

• For proper performance the air gap should be 0.6 mm ±0.3 mm

• In an optimal mounting, the signal amplitude values generated by the encoder, would be in the middle of the range of the signal plot shown in the Encoder Explorer software (see plot below). This may vary according to the encoder type.

• Verify proper rotor mounting with the Encoder Explorer tools “Signal analyzer” or “Signal verification process.”

Electrical Connection

This chapter reviews the steps required to electrically connect the encoder with digital interface (SSi or BiSS-C).
Connecting the encoder
The encoder has two operational modes:

Absolute position over SSi or BiSS-C
This is the power-up default mode

SSi / BiSS interface wires color code

Data

Data +| Green
GND| Black| Ground
+5V| Red| Power supply

SSi / BiSS output signal parameters

Digital SSi Interface
Synchronous Serial Interface (SSi) is a point to point serial interface standard between a master (e.g. controller) and a slave (e.g. sensor) for digital data transmission.

Built In Test option (BIT)

• The BIT indicates critical abnormality in the encoder internal signals.
• ‘0’ – the internal signals are within the normal limits, ‘1’ – Error
• The Part Number of the encoder indicates whether the encoder includes BIT. If no BIT is indicated in the PN, there is no additional error bit.

Digital BiSS-C Interface
BiSS – C Interface is unidirectional serial synchronous protocol for digital data transmission where the Encoder acts as “slave” transmits data according to “Master” clock. The BiSS protocol is designed in B mode and C mode (continuous mode). The BiSS-C interface as the SSi is based on RS-422 standards.

Built In Test option (BIT)

• The BIT indicates critical abnormality in the encoder internal signals.
• ‘1’ – the internal signals are within the normal limits, ‘0’ – Error
• The Part Number of the encoder indicates whether the encoder includes BIT. If no BIT is indicated in the PN, the error bit is always 1.

Bit allocation per encoder-resolution|  | Description Default| Length
---|---|---|---
17bit| 18bit| 19bit| 20bit|  |  |  |
27| 28| 29| 30| Ack| Period during which the encoder calculates the absolute position, one clock cycle| 0| 1/clock
26| 27| 28| 29| Start| Encoder signal for “start” data transmit| 1| 1 bit
25| 26| 27| 28| “0”| “Start” bit follower| 0| 1 bit
8…24| 8…25| 8…26| 8…27| AP| Absolute Position encoder data|  | Per resolution
7| 7| 7| 7| Error| BIT (Built In Test option)| 1| 1 bit
6| 6| 6| 6| Warn.| Warning (non active)| 1| 1 bit
0…5| 0…5| 0…5| 0…5| CRC| The CRC polynomial for position, error and warning data is: x6 + x1 + x0. It is transmitted MSB first and inverted.

The start bit and “0” bit are omitted from the

CRC calculation.

|  | 6 bits
 |  |  |  | Timeout| Elapse between the sequential “start”request cycle’s|  | 25 μs

Setup mode over NCP (Netzer Communication Protocol)
This service mode provides access via USB to a PC running Netzer Encoder Explorer application (on MS Windows 7/10). Communication is via Netzer Communication Protocol (NCP) over RS-422 using the same set of wires.
Use the following pin assignment to connect the encoder to a 9-pin D-type connector to the RS-422/USB converter CNV-0003 or the NanoMIC.

Electric encoder interface, D Type 9 pin Female

SSi Clock / NCP RX

| Gray| Clock / RX +| 2
Blue| Clock / RX –| 1

SSi Data / NCP TX

| Yellow| Data / TX –| 4
Green| Data / TX +| 3
Ground| Black| GND| 5
Power supply| Red| +5V| 8

Connect Netzer encoder to the converter, connect the converter to the computer and run the Electric Encoder Explorer Software Tool

Electrical connection and grounding
Observe the following grounding consideration:

1. The cable shield electrically floating (unconnected) by default.
2. It’s highly recommended to keep the motor PWM wires electrically shielded and/or kept away from the encoder.
   Note: 4.75 to 5.25 VDC power supply required

Signal Verification

Starting the Encoder Explorer
Make sure to complete the following tasks successfully:

• Mechanical Mounting
• Electrical Connection to the encoder
• Encoder Explore Software Installation

Run the Encoder Explorer tool (EE)

• Ensure proper communication with the encoder: (Setup mode by default).

• The Encoder position-dial is colored blue when in Setup Mode, either through the NanoMic or the BlueBox (a). Note that the operational mode is not available through the BlueBox (b).

• The Signal amplitude bar indicates whether the signal is within the acceptable tolerance (c) . Note that prior to performing the Signal Verification process the bar could indicate an out of tolerance signal (d).

• Encoder data is displayed in the encoder data area (CAT No., Serial No.) (e).

• The position dial display responds to shaft rotation (f).

• It is important to perform the Signal Verification process prior to the calibration of the encoder to ensure optimal performance.

Signal verification process

• The Signal Verification process ensures that the encoder is mounted correctly and provides good signal amplitudes. This is performed by collecting raw data of the fine and coarse channels during rotation.

  • Select on the main screen (a).

  • Select to initiate the process (b).

  • Rotate the shaft in order to collect the fine and coarse channels data (c).

• If the process is successful, the status “Signal verification successful” would appear (d).

• The ‘amplitude circle’ would be centered between the two green circles, preferably in the middle of the tolerance (e).

• Note however, that mounting the encoder towards the extreme mechanical tolerances might cause the amplitude circle to be offset from the exact middle of the nominal position.

• If the signal is out of tolerance the Error notification “Amplitude is lower/higher than the min/max limit of XXX” would appear (g).

• In Addition, the status “Signal verification failed – perform calibration amplitude” would appear at the top (h).

  • Stop the process and re-mount the encoder, making sure that the mechanical installation tolerances are not exceeded, removing or adding shims as required.
  • Repeat the Signal Verification process after the remount.

• Once the signal verification process is successfully completed, proceed to the encoder calibration phase, Section 13

Calibration

It is important that upon every installation of the encoder, the Signal Verification process is completed prior to attempting calibration of the encoder.
For encoders with FW 4 version 4.1.3 or higher, it is possible to select either a fully automated calibration process, or a manual phase-by-phase calibration process.

Auto-calibration

Auto Calibration is supported by encoders with FW 4 version 4.1.3 or higher.
For these encoders an additional “Auto-calibration” button is displayed.

Auto-calibration process
The Auto-calibration process consists of three stages:

1. Jitter test – evaluates the electric noise for the Fine, Medium, and Coarse encoder channels. During the jitter test, the shaft must be stationary.
   Attention! The Pass/Fail criteria of the Jitter test is according to very strict factory criteria and failing it would abort the Auto Calibration process.
   However, the manual Jitter test as part of the Manual Calibration process in section 13.4, would enable the user to decide whether the jitter is acceptable to its needs.

2. Offset calibration – performs the offset calibration, the shaft must rotate continuously.

3. Absolute Position (AP) calibration – performs Coarse Amplitude Alignment (CAA) and Medium Amplitude Alignment (MAA) are calculated.
   During Auto-Calibration process the encoder’s Zero-Position remain in the factory default zero position for new encoders. It is possible to set the Zero Point through the top menu bar, by selecting “Calibration” tab, and clicking “Set UZP” as defined in section 13.3.

Performing Auto-calibration

• Press the button.

• The main auto-calibration window opens.

  • Select the appropriate measurement range applicable to your application (a).

  • Make sure to keep the shaft still and press the

• The Noise test would be performed and upon successful completion the “Noise test” label will be marked with a green check mark.

• The Offset calibration would automatically start upon completion of the Noise test. This calibration requires that the shaft be rotated continuously.

• The AP calibration would automatically start upon completion of the Accuracy Calibration. Continue rotating the shaft in this phase until the AP calibration is completed, and the encoder is reset.

• Once the reset is over, the Auto-calibration process is successfully finished.

• The user can review the calibration results by clicking the button (b).

• It is always possible to abort the Auto Calibration process by clicking the button (c).

Auto-calibration failures

• If a test fails (for example the Noise test) – the result will be marked with in red X.

• If the calibration process failed, corrective recommendations will be displayed, corresponding to the element which had failed the test.

• It is possible to review detailed information regarding the failure, by clicking the button (d).

Manual calibration

The Manual calibration process consists of the following stages:

1. Offset calibration – performs the offset calibration, the shaft must rotate continuously.
2. CAA / MAA Calibration – performs Coarse Amplitude Alignment (CAA) and Medium Amplitude Alignment (MAA) are calculated
3. Zero Position Set – Used to determine a Zero Position other than the factory default.
4. Jitter Test – Used to determine the amount of jitter and allow the user to decide if acceptable.
   Select on the main screen (a).

Offset calibration

• In this process, the DC offset of the sine and cosine signals are compensated over the operational sector (offset calibration).

  • Click (b).
  • Rotate the shaft continuously during data collection, covering the whole working sector of the application from end to end. The progress bar (c) indicates the progress of the data collection.

• Rotation speed is not a parameter during data collection. By default, the procedure collects 500 points. The collected data for the fine / coarse channels, should be a clear “thin” circle which appears in the center of the plots (d) (e) with a possible slight offset.

  • When offset calibration is completed, click on <Continue to CAA/MAA Calibration> button (f).

Calibration of Coarse Amplitude Alignment (CAA) & Medium Amplitude Alignment (MAA)

• The following calibration aligns the coarse channel, and medium channel in certain encoders, with the fine channel by collecting data from each point in both channels. This is performed to make sure that every time the encoder is turned on, it would provide an accurate absolute position.

  • Select the relevant option from the Measurement Range options (a):

  • Full mechanical rotation – shaft movement is over a full 360 degrees rotation – (that is the recommended calibration).

  • Limited section – shaft has a limited rotation angle which is less than 360 degrees. In this mode you need to input the rotation range by degrees.

  • Free sampling mode – sets the number of calibration points in accordance with the total number of points in the text box. The system displays the recommended number of points by default. The minimum points over the working sector is nine.
    Note that the Total number of points would change to the optimal default according to the selected measurement range above.

  • Click the button (b).

• The Calibration process control (c) indicates the current position, and the next target position to which the shaft should be rotated.
  Rotate the shaft to the next position, stop and click the button to sample the position (d). The shaft should be at STAND STILL when clicking the button.

• The Shaft movement status (e) indicates the shaft movement status.

  • Complete the sampling process using the following routine: positioning the shaft –> stand still –> clicking (d) to sample the position.
  • When the process is completed click the button (f).

Setting the zero-position of the encoder
Select one of the options for setting the zero point and click <Apply and close>.

• It is possible to set either current position or rotate the shaft to any other position to be set as the zero point.

• It is also possible to set the Zero Point through the top menu bar, by selecting “Calibration” tab, and clicking “Set UZP”.

Jitter test

• The jitter test is used evaluate the level of electric noise.

• Common jitter should be up +/- 3 counts; higher jitter may indicate system noise and would require better grounding or shielding of the electric noise source.

  • Select “Calibration” tab, and click “Jitter Test”

  • Select the Jitter test mode (a).

  • Set the Timing and Sampling parameters (b).

  • Click button (c) and check if the results (d) are within acceptable tolerances for the intended application.

• Another indication of excessive jitter/noise when the blue dots in signal amplitude circle are not evenly distributed on a thin circle as appears below.

Operational Mode

SSi / BiSS

• Operational Mode indication of the SSi / BiSS encoder interface is available by using the NanoMIC to connect with the encoder. When in Operational Mode the color of the position dial is orange.
• For more information read about NanoMIC on Netzer website
• The operational mode is using SSi / BiSS interface with 1MHz clock rate.
• The encoder position-dial is colored orange when in Operational Mode. The bar below the dial, is the corresponding binary word output for the current shaft position (a).

ABOUT COMPANY

Corporate Headquarters

• ISRAEL
  • Netzer Precision Position Sensors A.C.S. Ltd.
  • Misgav Industrial Park, P.O. Box 1359
  • D.N. Misgav, 2017400
  • Tel: +972 4 999 0420
• USA
  • Netzer Precision Position Sensors Inc.
  • 200 Main Street, Salem
  • NH 03079
  • Tel: +1 617 901 0820
  • www.netzerprecision.com

References

• Rotary Encoders : Absolute Position Sensors by Netzer

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