---
title: "Quick Start: Web Width Measurement — Digital Monitoring — SCU5"
application: web-width
variant: digital
controller: scu5
valid_sensors: ["ODC 48", "ODC 96", "ODC 192", "ODC 288", "ODC 384", "ODC 480", "ODC 768", "ODC 960"]
output_type: digital
estimated_time: "~1–2 hours (single sensor), ~2–3 hours (dual sensor)"
last_updated: "2026-07-14"
guide_url: "https://r2r.tech/resources/quick-start/web-width/digital/scu5"
pdf_url: "https://r2r.tech/resources/quick-start/web-width/digital/scu5.pdf"
---

# Quick Start: Web Width Measurement — Digital Monitoring — SCU5

> Install, wire, and configure a Roll-2-Roll® ODC sensor with a SCU5 controller for web width measurement via Digital Monitoring.

## 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:** ~1–2 hours (single sensor), ~2–3 hours (dual sensor)

## What You Need

### Products

- ODC Family sensor — sized for your web width (full sizing guidance under Install)
- SCU5 DIO controller (display + digital input/output)
- Quick Disconnect Sensor Cable - 3m (10 ft) (U2-01975)
- 24 V DC Input Power Cable, Length 5 m (21218-5m)
- M12 12-pin Digital I/O Cable (3m) (21228-3m)
- 24 VDC power supply
- For dual sensor: second ODC Family sensor + second sensor cable (U2-01975)

*Note: 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

- Machine accessible and safe to work on
- 24 VDC power available at the installation location
- For Ethernet paths: Ethernet network ready (switch port available, IP address planned)
- For digital monitoring paths: stacklight, alarm, or PLC digital input wired and ready
- Web material available for initial setup and teach operations
- A sample of known width on hand for the teach correction/offset step

## 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.

| Model | Outputs |
|-------|---------|
| SCU5 DIO | Digital 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)DIO | Digital GO/NO-GO pass/fail outputs, plus Industrial Ethernet width data |

## Install

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).

### Single Sensor Setup

- Position the sensor so both edges of the web are visible within the sensor field of view
- Allow margin on each side for normal web wander — do not position edges at extremes of the sensing range
- Mount closer to one roller to minimize web flutter
- Ensure the web plane is parallel to the sensor length axis

### 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.

**Sensor sizing:** 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.

**Reference documents:**

- [Sensor Installation Recommendations (inspection applications)](https://r2r.tech/documentation/manuals/sensor-installation-recommendations-inspection-applications.md)

## Wire

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

*Note: NPN 24V-compatible outputs indicate: width within tolerance, width above upper limit, width below lower limit.*

## 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.

### Single Sensor Width

One sensor sees both edges of the web and computes width directly. Use when the web is narrower than the sensor sensing range.

1. Connect sensor and power on — the controller detects both edges and displays width on the touchscreen
2. Set the nominal width on the touchscreen
3. Set the upper limit (max acceptable width) and lower limit (min acceptable width)
4. NPN outputs activate when measured width exceeds the upper or lower limit

**Teaching:**

1. Place a sample of known width in front of the sensor
2. Enter the known width value on the touchscreen or via Ethernet
3. Press the Teach Correction button
4. The controller compares raw measurement to known value and stores the difference
5. All subsequent width readings include this correction

**Success:** Both edges detected (green indicators on touchscreen), width value displayed and updating in real time. NPN outputs inactive when width is within tolerance; active when width exceeds limits.

### 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

*Note: 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.*

**Success:** 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)

**Configuration reference:** [Controller Documentation](https://r2r.tech/documentation/manuals/scu5-sensor-and-web-guide-controller-user-manual-v36n.md)

## Go Further

### Related Quick Start Guides

- Contrast-Based Width Measurement — Measuring coating width, feature width, and contrasting boundaries (coming soon)
- [Multiple Web Width Measurement](https://r2r.tech/resources/quick-start/multi-web-width/ethernet/scu6x.md) — Measure multiple strips or webs simultaneously (SCU6x only)
- [Position Measurement](https://r2r.tech/resources/quick-start/position-measurement/ethernet/scu6x.md) — Measure edge, centerline, or contrast/line position
- [Splice Detection](https://r2r.tech/resources/quick-start/splice-detection/ethernet/scu6x.md) — Add splice detection alongside width measurement

### Learn More

- [Web Width Measurement and Monitoring](https://r2r.tech/articles/web-width-measurement.md)

### Reference Documents

- [SCU5 User Manual](https://r2r.tech/documentation/manuals/scu5-sensor-and-web-guide-controller-user-manual-v36n.md)
- [Sensor Installation Recommendations (inspection applications)](https://r2r.tech/documentation/manuals/sensor-installation-recommendations-inspection-applications.md)

## Available Sensor Models

Select a sensor model at the guide page to see datasheets, 2D drawings, 3D models, and STEP file downloads.

- [ODC 48](https://r2r.tech/resources/quick-start/web-width/digital/scu5.md?sensor=odc-48) (48 mm)
- [ODC 96](https://r2r.tech/resources/quick-start/web-width/digital/scu5.md?sensor=odc-96) (96 mm)
- [ODC 192](https://r2r.tech/resources/quick-start/web-width/digital/scu5.md?sensor=odc-192) (192 mm)
- [ODC 288](https://r2r.tech/resources/quick-start/web-width/digital/scu5.md?sensor=odc-288) (288 mm)
- [ODC 384](https://r2r.tech/resources/quick-start/web-width/digital/scu5.md?sensor=odc-384) (384 mm)
- [ODC 480](https://r2r.tech/resources/quick-start/web-width/digital/scu5.md?sensor=odc-480) (480 mm)
- [ODC 768](https://r2r.tech/resources/quick-start/web-width/digital/scu5.md?sensor=odc-768) (768 mm)
- [ODC 960](https://r2r.tech/resources/quick-start/web-width/digital/scu5.md?sensor=odc-960) (960 mm)

## Related Quick Start Guides

- [Splice Detection — Industrial Ethernet — 1DC Series](https://r2r.tech/resources/quick-start/splice-detection/ethernet/1dc.md)
- [Splice Detection — Industrial Ethernet — SCU6x](https://r2r.tech/resources/quick-start/splice-detection/ethernet/scu6x.md)
- [Splice Detection — Digital Output — SCU6x](https://r2r.tech/resources/quick-start/splice-detection/digital/scu6x.md)
- [Position Measurement — Analog Output — SCU5](https://r2r.tech/resources/quick-start/position-measurement/analog/scu5.md)
- [Position Measurement — Industrial Ethernet — SCU5](https://r2r.tech/resources/quick-start/position-measurement/ethernet/scu5.md)
- [Position Measurement — Industrial Ethernet — SCU6x](https://r2r.tech/resources/quick-start/position-measurement/ethernet/scu6x.md)
- [Position Measurement — Industrial Ethernet — 1DC Series](https://r2r.tech/resources/quick-start/position-measurement/ethernet/1dc.md)
- [Web Width Measurement — Analog Output — SCU5](https://r2r.tech/resources/quick-start/web-width/analog/scu5.md)
- [Web Width Measurement — Industrial Ethernet — SCU5](https://r2r.tech/resources/quick-start/web-width/ethernet/scu5.md)
- [Web Width Measurement — Digital Monitoring — SCU6x](https://r2r.tech/resources/quick-start/web-width/digital/scu6x.md)
- [Web Width Measurement — Industrial Ethernet — SCU6x](https://r2r.tech/resources/quick-start/web-width/ethernet/scu6x.md)
- [Web Width Measurement — Industrial Ethernet — 1DC Series](https://r2r.tech/resources/quick-start/web-width/ethernet/1dc.md)
- [Multiple Web Width Measurement — Industrial Ethernet — SCU6x](https://r2r.tech/resources/quick-start/multi-web-width/ethernet/scu6x.md)
- [Multiple Web Width Measurement — Digital Monitoring — SCU6x](https://r2r.tech/resources/quick-start/multi-web-width/digital/scu6x.md)
- [Multiple Web Width Measurement — Industrial Ethernet — 1DC Series](https://r2r.tech/resources/quick-start/multi-web-width/ethernet/1dc.md)

## Support

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