+1 (888) 290-3215 experts@r2r.tech

Position Measurement — Industrial Ethernet — SCU6x

Quick Start Guides › Position Measurement
Change Selection

Start here Select Your Sensor

Pick your ODC Family model to unlock datasheets, 3D models, support files, and your exact ordering list:

Not sure which size? Pick the sensor wide enough for your max expected wander + 10% margin. View all ODC Family models

Select your sensor model above to unlock datasheets, 3D models, support files, and your exact ordering list for this guide.

✓ What You'll Achieve

After completing this guide, wired to your SCU6x controller with position data available over Industrial Ethernet for your PLC.

Estimated time: ~1–2 hours

This guide covers 3 measurement types — same sensor, different configuration:

Edge Position

Tracks one physical edge (left or right) of the web.

Centerline Position

Tracks the midpoint between both edges — absorbs width variation. In center mode the sensor sees both edges, so the web appears as a white rectangle on the controller display with black regions on both the left and the right.

Contrast/Line Position

Tracks a printed line, coating edge, or color boundary on the web surface.

☐ What You Need

SCU6x Ethernet

Prerequisites

Sensor size selection: Choose sensor wide enough for maximum expected wander + 10% safety factor. For centerline, sensor must be wider than the web. For contrast/line, sensor only needs to see the tracked feature.

SCU6x Output Options

SCU6x models differ by output: C(x)D provides Industrial Ethernet, and C(x)DIO adds digital GO/NO-GO pass/fail outputs on top. (SCU6x has no analog output.)

ModelOutputs
SCU6x C(x)DIndustrial Ethernet position data (edge and centerline positions — loggable)
SCU6x C(x)DIOIndustrial Ethernet position data, plus digital GO/NO-GO pass/fail outputs

1 Install the Sensor

Mounting differs based on measurement type.

Edge & Centerline

  • Mount in free span between two rollers (web unsupported)
  • Web edge must be at least 10 mm from the edge of the sensor sensing range
  • Mount closer to one roller to minimize web flutter
  • Web plane must be parallel to sensor length axis
  • For centerline: sensor must see both edges (or use dual sensors for wide webs)
Light source:
Edge: Infrared (IR) — default for edge and centerline on most materials
Contrast: White light — for visible color contrast. UV for fluorescent marks only.

Reference Documents

2 Wire the System

Same sensor cable as SCU5. Ethernet via M12 D-coded connector.

  1. Sensor: Connect Quick Disconnect Sensor Cable (U2-01975) from ODC sensor to SCU6x port S1
  2. Power: Connect 24 V DC Input Power Cable for SCU6x or 1DC (21218x-5m) to SCU6x port Z2
  3. Ethernet: Connect M12 to RJ45S, Shielded Cable (21222-3m) from SCU6x port P1 to PLC or network switch

3 Configure & Verify

All three measurement types use the same sensor hardware. The type is selected in the controller configuration.

Edge Position

Tracks one physical edge (left or right) of the web.

  1. Connect sensor and power on — edge position appears immediately
  2. Set the sensor's electronic orientation (left or right) to match its physical orientation with respect to the web. When set correctly, the web appears as a white rectangle on the controller display with one black region: the left region is black when tracking the left edge, the right region when tracking the right edge.
  3. For analog: select edge type (left/right/center/width) and output range
  4. For Ethernet: position is immediately available in registers
What success looks like: The Web Detect Indicator — the green square at the bottom-left of the SCU5 or SCU6x display — turns green (it lights when the controller sees a valid edge or a valid taught contrast); quality factor > 10; stable position value tracking web movement.

Common Configuration Mistakes

  • No backup roller — web flutter corrupts pattern matching
  • Teaching on the wrong feature
  • Tolerance too tight (intermittent loss) or too loose (false matches)
  • Ambient light interference
  • Forgetting to re-teach after material change

View full configuration documentation

Troubleshooting
SymptomLikely CauseFix
The web position bar on the SCU6x display is completely white (single-sensor setup). The sensor's electronic orientation does not match its physical orientation with respect to the web. Change the sensor's electronic orientation (left → right or vice versa) so it matches the sensor's physical orientation with respect to the web. Set correctly, the web shows as a white rectangle with the left region black when tracking the left edge, or the right region black when tracking the right edge.
The web position bar on the SCU6x display is completely white (dual-sensor setup). One or both sensors' electronic orientation does not match their physical orientation with respect to the web. Configure each sensor so its electronic orientation matches its physical orientation with respect to the web — one sensor tracking the left edge, the other the right.

4 PLC Integration

Position, quality factor, fault status, and coverage are exchanged in a single cyclic frame over Industrial Ethernet.

  • Position units are pixels, not mm. Convert using your sensor's pixel resolution: position_mm = position_pixels × resolution, where resolution is 0.0635 mm or 0.127 mm per pixel depending on the sensor model.
  • Rockwell AOI handles conversion automatically and exposes _mm fields
  • Update rate: 50 Hz (20 ms) fixed — not configurable over Ethernet
  • Quality factor > 10 = valid reading

📄 The register map, EDS file (EtherNet/IP), and Add-on Instruction (AOI) for Studio 5000 are in the Your Products section above — grouped on the product card with everything else you need to download.

+ Go Further

Related Quick Start Guides

Learn More

Need Help?

Email: experts@r2r.tech
Phone: +1-888-290-3215