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1 Axis VRO VRO with UniSlide VRO with XSlide VRO with XY UniSlide VRO with XYZ UniSlide

VRO Encorder Readout

VRO Readout

The Velmex VRO™ Encoder Readout is a compact one and two axes digital readout for linear and rotary incremental encoders. The VRO can be used in conjunction with most of Velmex's products.

Velmex VRO™ Delivers Ultra-Precise Position Readouts

The Velmex VRO Digital Readout delivers precise position information generate by linear or rotary incremental encoders. This compact, microprocessor uses the latest OLED display and DSP micro-controller technology. While the VRO was designed for use with differential type encoders, it is fully compatible with single-ended encoders. It easily and accurately reads the position signals generated from the encoder connected to either a one or two axis motion control system.

The VRO's advance technology delivers an exact, consistent performance and insures they are very efficient, reliable and easy to program. It's LED display has high visibility, high resolution and low energy consumption.

Velmex VRO™ Features

VRO Features

Additional VRO operating features:

• Automatic back-up of current settings.
• Sleep mode saves energy, extends life.
• Internal self-diagnostics makes troubleshooting easy.
• Compatible with all 5v incremental encoders.

Encoders interface with the VRO through Schmitt triggers and digital filtering with quadrature decoding returning instantaneous results at maximum resolution. The Velmex VRO Readout System can be used in conjunction with Velmex's VXM™ Motor Controller and with both manually-operated or motorized UniSlides®, BiSlides® and XSlides™.

VRO™ Configurations

Single Axis VRO Readout

VRO-1 – One Axis Encoder Readout – Reads and reports on an encoder connected to a single axis Velmex stage.

Two Axis VRO Readout

VRO-2 – Two Axis Encoder Readout – Reads and reports on encoders connected to two different axis. Multiple VRO-2 can be used with multi-axis stages.

VRO-1 with Base

VRO-1B – One axis VRO-1 version with tilt base. Allows for easier reading.

VRO-2with Base

VRO-2B – Two axis VRO-2 version with tilt base.

Also available:

VRO-1H - One axis VRO-1 version with T-slot hinge for mounting on BiSlide framing

VRO-2H - Two axis VRO-2 version with T-slot hinge for mounting on BiSlide framing

For information on obsolete Controllers and Readouts see the Controls Archive

For information on Encoders available, please see the Encoder Page.

VRO™ Specifications

  Enclosure: Aluminum Black Anodized, IP30 rated  
VRO-1 Weight (VRO-1) 1.00 lbs. (459 g)
VRO-2 Weight (VRO-2) 1.06 lbs. (481 g)
  Height (VRO-1/2) 4.27" (108.5 mm)
VRO with tilt base Height (VRO-1B/2B)
with Tilt Base
5.50" (140 mm)
  Width (all versions) 6.87" (174.5 mm)
VRO-2 Depth (VRO-1/2) 1.89" (48 mm)
VRO with tilt base Depth (VRO-1B/2B)
with Tilt Base
3.5" (89 mm)
AC Power Adapter:
VRO Power Supply Weight 0.29 lbs. (300 g)
Height 1.8" (46 mm)
Width 1.4" (36 mm)
Length (without cord) 2.8" (73 mm)

VRO Dimensions VRO Feature Callouts

Format 2 Line x 16 Character
Type OLED, Green
Contrast Ratio 2000:1 (readable in direct sunlight)
Character Height 0.35" (9 mm)
Viewing Angle 160 degrees
Half-life 50,000 hours
Tilt Range (Tilt Base) 75 degrees
Maximum displayable count: ±999,999,999
Maximum internal count: ±2,147,483,647
Maximum count rate: 1.6 MHz
Encoder Inputs: 4x quadrature differential line receivers, Schmitt trigger with low pass digital filtering
Maximum power output: 330ma per encoder
  RoHS compliant
Electrical Requirements:
AC Power Adapter 90-264VAC 0.4A 47-63Hz
VRO 5VDC ±2% 1.0A
Power Connector 5.5 mm (type N) 2.5 mm ctr pin positive
Encoder: 4.87 to 5.13 VDC, 330 ma maximum input
  Differential or Single Ended Interface
Operating Temperature: 0°-120° F (-18°-49° C)
Relative Humidity: 10%-90% (noncondensing)
RS-232 Port Configuration

8 Data, No Parity, 1 Stop, 9600 baud rate default (19200, 38400 baud rate user settable)

VRO Serial Number

VRO Serial Number

VRO Readouts have serial numbers which can be located on the right side of the device.

Options/Accessories for use with the Velmex VRO™

Various options and accessories are available to configure a VRO Encoder Readout for specific applications.

VRO Tilt Base with VRO

Tilt Base - Optional tilt base changes the tilt angle for added visibility and operator comfort. More details on VRO Components Page.

Back of VRO with Hinge

T-slot Hinge – T-slot hinge allows mounting and placing were most convenient. With the T-slot, the VRO can be easy added to the support structure that might be used with a Velmex BiSlide®. Once mounted the VRO can be tilted for easy viewing. More details on VRO Components Page.


T-slot Mounting Flange – T-Slot mounting flange facilitates mounting of the VRO virtually any where needed for a fixed permanent installation. For example mounting in a panel box or on a wall. Placement of the VRO would be fixed. In order to adjust the tilt use the T-slot hinge to mount instead. More details on VRO Components Page.

Power Supply

Power Supply - The universal power supply is standard with all VRO Readouts. It can also be ordered separately.

Power Strip

Power Strip – Convenient power strip for plugging in multiple VROs and VXMs™.

International Power Adapters

International Power Adapters – a variety of international-rated power adapters are available.

VRO Cables

Assorted Cable Adapters - Various adapters are available to connect to computer via USB and to various brands of linear and rotary encoders.


USB to RS232 - allows the VRO Readout to communicate with the computer. (10 ft.)

Encoder Cables - connects the encoders to the VRO to transfer position data. (Specified based on travel length.)

VRO End Caps

End Caps Rubber end caps protect the corners of the VRO Readout and the component connections from accidental damage.

VRO Moisture Protection

Vinyl Bag A clear vinyl bag protects the VRO from fogging in high moisture situations and/or transporting outdoors.

VRO Tab2 Remote

VRO-Tab 2 Hand-held, two button remote which provides a convenient capture (upload VRO reading to computer) and reset of the VRO for faster data collection. Additional information on VRO Components Page.

COSMOS for VRO C.O.S.M.O.S.™ (Computer Optimized Stepper Motor Operating System) can be used in conjunction with a Velmex VRO™ Readout. It coordinates communication between the computer and the VRO readout. While its primary function is to aid set-up and programming of the VXM™ Controller to control Velmex motorized positioning systems, COSMOS can send commands to emulate the buttons on the front panel VRO Readout.

See Software for more information on COSMOS, along with computer notes, drivers and VXM programming examples.
COSMOS for VRO Encoders - A variety of encoders that can be read by the VRO are available from Velmex that deliver an ultra-precise reading of the position of the carriage (slider) of various Velmex stages. Encoders offered include magnetic, inductive or rotary modes. For details, please see the Encoder page.


VRO Readout Downloads
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VRO™ Documents, Spec Sheets, User Manuals, Instructions
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Type File Name Description Download View
PDF VRO Spec Sheet.pdf Overview of the VRO with specifications Download Button View PDF
PDF VRO Quick Start Guide.pdf Basic set-up and run for the VRO Readout Download Button View PDF
PDF VRO Reference Manual.pdf Detailed specifications, usage instructions and care and maintenance. Download Button View PDF
Encoder Information - See also the Encoder Section
PDF Encoder Overview.pdf Specifications for the encoders offered by Velmex Download Button View PDF
PDF Inductive_LinearTapeEncoders.pdf Specifications for AMO Inductive Encoders Download Button View PDF
PDF Inductive-Encoder-Installation.pdf Installation instructions for AMO Inductive Encoder Download Button View PDF
PDF Magnetic_Encoder_Specs.pdf Specifications for Magnetic Encoders Download Button View PDF
PDF Magnetic-Encoder-Data-Sheet.pdf Overview of features for Elgo Magnetic Encoders Download Button View PDF
PDF Magnetic-Encoder-Op-Manual.pdf Operating Manual for Elgo Magnetic Encoders Download Button View PDF
PDF Rotary-Encoder-Lead-Screw.pdf Operating manual and specifications for HEDs Rotary Encoder used on the linear lead screw Download Button View PDF
PDF Rotary-incremental-encoder.pdf Specifications for Rotary Encoder used on the BEI double-shaft motors Download Button View PDF
PDF EPC Rotary Encoder Spec Sheet.pdf Specifications for EPC Rotary Encoder primarily used on the XSlide Download Button View PDF
PDF Rotary Encoder Selection.pdf Recommended Rotary Encoder for Velmex linear and rotary stages Download Button View PDF
PDF Encoder Connections and Cable Wiring.pdf Instructions - Wiring diagrams for Encoder cable connection to VRO Readout Download Button View PDF
.XLS VRO Units Calculator in_mm.xls Calculator for VRO Units for Rotary Encoders (inch/mm) Download Button  
.XLS VRO Units Calculator mm_in.xls Calculator for VRO Units for Rotary Encoders (mm/inch) Download Button  
.XLS VRO Units Calculator Linear in_mm.xls Calculator for VRO Units for Linear Encoders (inch/mm) Download Button  
.XLS VRO Units Calculator Linear mm_in.xls Calculator for VRO Units for Linear Encoders (mm/inch) Download Button  

VRO™USB to RS232 Cable Drivers
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Type Operating System File Name Description Access
LINK Universal .ftdichip.com/Drivers/VCP.htm Web page with access to the cable drivers for various operating systems so that the application software can access the USB as a standard COM port. Download Button


Troubleshooting Downloads Description Version
Serial Port Diagnostics Download for Diagnostics Diagnostics for driver issues 3.1.0


For more information on obsolete Controllers and Readouts see the Controls Archive

Velmex VRO™ Applications and Examples

These are examples of Velmex products. If you wish a similar product, please contact us with your specific application specifications (travel distance, payload, hours per day in use, resolution, speed range, etc.). You can use the Request Assistance form.

The example displayed may be a custom configuration, designed to the customer's specifications; and not offered as a standard product. Custom configurations could contain custom, externally-fabricated components.

Pictured in our gallery are examples that show the VRO connected to various encoders on other Velmex products. Product and accessory offering is subject to change and availability.

Example Key Code Meaning Example Key Code Meaning
A Manually Operated M Motorized
S Standard C Custom Configuration
B BiSlide U UniSlide
X XSlide R Rotary Tables
T XY Tables TT Turntables
E Elevating Tables FS Fun Stuff (Ingenious, Cool, or Just out of the ordinary applications)


Single Axis Stages with the Velmex VRO Readout
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Multiple-Axes Stages with the Velmex VRO Readout
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Combination Assemblies
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Sorry, we don't have any images of our manual tables in a working application. Please check back later.


Working Images
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  • VRO and UniSlide measuring tree core description
    Tree Ring Lab
  • VRO and UniSlide in Tree Ring Lab description
    Tree Cookie

Examples of other Velmex products can be found on the Examples page or in the Examples section for each product.






Many questions can be answered by reviewing the "Features", "Model / Series", "Specifications", "Options / Accessories" and "Technical Documentation" sections for each product line. Additional FAQs about product comparisons, product construction, purchasing and shipping can be found on the company FAQ page.

VRO™ Readout FAQs

For how many axes can the VRO Readout interpret positioning?

The VRO can provide a readout from linear and rotary encoders for one or two axes. The axes can be configured in X, XY and XZ. An XYZ or other multi-axis configuration would require additional VRO Readouts.

Are there specific encoders the VRO will work with?

The VRO was designed for differential type encoders, however, it is fully compatible with single-ended encoders.

What standard of measurement does the VRO Readout use?

The VRO can report position in either Imperial English or metric. It can count revolutions. It also can report in degrees when connected to a rotary encoder.


If you have questions about your specific application or want us to design a system incorporating encoders and the Velmex VRO Readout, please complete the Request Assistance form or call Velmex to speak to one of our Application Engineers.