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

Web Width Measurement — Digital Monitoring — SCU5

Quick Start Guides › Web Width 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 SCU5 DIO controller with pass/fail monitoring output — width within tolerance, width too narrow, or width too wide — on 24V-compatible NPN outputs for your stacklight, alarm, or PLC.

Estimated time: ~2–3 hours

☐ What You Need

SCU5 Digital Monitoring

Which controller variant? DIO = Display + Input/Output (24V-compatible NPN pass/fail outputs), no Industrial Ethernet. Choose the DIO+ variant to also output the live width value as an analog signal alongside the GO/NO-GO outputs — one controller then gives you both continuous measurement and pass/fail.

Prerequisites

Sensor size selection: Single sensor: sensing range must exceed max web width + wander. Dual sensor: each sensor covers its respective edge + wander. If no single sensor is wide enough, use dual sensor.

SCU5 Output Options

The "+" is the analog-output option — it adds a live analog signal of the width value on top of the model's base capability, so a single controller can drive more than one output at once.

ModelOutputs
SCU5 DIODigital GO/NO-GO pass/fail outputs
SCU5 DIO+Digital GO/NO-GO pass/fail outputs, plus an analog output of the width value
SCU5 C(x)DIODigital GO/NO-GO pass/fail outputs, plus Industrial Ethernet width data

1 Install the Sensor

Edge-based web width measurement always uses free span mounting (web unsupported between rollers). Install the sensor so that the length of the sensor is parallel to the cross-machine direction (the width direction of the web).

Dual Sensor Installation: For dual-sensor width measurement, mount both sensors with the same camera orientation (facing the same direction). Then set their electronic orientation so that, relative to the web, one sensor tracks the left edge and the other tracks the right edge — see Sensor Installation Recommendations for orientation details.

Dual Sensor Setup

  • Position the left sensor to see the left edge, right sensor to see the right edge
  • Critical: mount both with the same camera (physical) orientation, but set their electronic orientation oppositely — the left sensor tracks the left edge, the right sensor the right edge
  • Each sensor needs margin for the full range of web widths (min to max) plus wander
  • Sensors do not need to be the same size — select each based on wander range at its edge
Light source: Infrared (IR) — default for most materials.

Reference Documents

2 Wire the System

Sensor(s) to SCU5, then digital monitoring output.

  1. Sensor: Connect Quick Disconnect Sensor Cable (U2-01975) from ODC sensor to SCU5 port S1 (and S2 for dual)
  2. Power: Connect 24 V DC Input Power Cable (21218-5m) to SCU5 port P1
  3. Digital I/O: Connect M12 12-pin Digital I/O Cable (21228-3m) from SCU5 Port 3 to stacklight/alarm/PLC digital inputs
NPN 24V-compatible outputs indicate: width within tolerance, width above upper limit, width below lower limit.
Dual Sensor Wiring: Connect second sensor cable to controller port S2.

3 Configure & Verify

Web width measurement computes the distance between the detected left and right edges. The controller computes the width internally and provides the value directly.

Dual Sensor Width

Two sensors — one per edge — with the controller computing total width including the distance between sensors. Use when the web is wider than any single sensor. Not available for 1DC.

  1. Set each sensor's electronic orientation first — left sensor → left edge, right sensor → right edge — then perform single-sensor configuration for each
  2. Teach offset: place a known-width sample so both sensors see their edges
  3. Enter the known width value and press the Teach Offset button
  4. The controller computes the distance between sensors and stores it
  5. Optionally perform teach correction after teach offset for additional accuracy
Teach offset = one-time during installation (re-teach only when sensors are physically moved). Teach correction = optional per product change. Final width = raw measurement + offset + correction.
What success looks like: Both sensors show green indicators, width reflects the full web width, changing products produces the expected width change.

Common Configuration Mistakes

  • Not re-teaching correction after product change — accuracy degrades with different material
  • Forgetting teach offset — width will be wildly incorrect (missing distance between sensors)

View full configuration documentation

+ Go Further

Related Quick Start Guides

  • Contrast-Based Width Measurement — Measuring coating width, feature width, and contrasting boundaries (coming soon)
  • Multiple Web Width Measurement — Measure multiple strips or webs simultaneously (SCU6x only)
  • Position Measurement — Measure edge, centerline, or contrast/line position
  • Splice Detection — Add splice detection alongside width measurement

Learn More

Need Help?

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