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, your web tracks a contrast boundary — a coating edge, color change, or stripe — and the stand shifts the roll to hold it on target.
Estimated time: ~30–60 minutes
What You Need
SCU5 · Contrast Guiding — What You Need
Prerequisites
Install the Web Guide
Install the Roll-2-Roll® Web Guide in two stages: first set up the shifting roll stand — carriage, linear bearings, and the high-thrust actuator — then mount the sensor for your guiding mode.
DANGER
Match the actuator mount to your existing structure
Identify whether your existing carriage uses a fixed (-RF) or floating (-TG) mount before ordering or installing the actuator. Fixed structures take an LHS-RF actuator; floating structures take an LHS-TG, BLA, or RLA sized to the load. Installing a fixed-mount actuator on a floating structure — or a floating-mount actuator on a fixed structure — will damage the actuator.
Install and Align the Roll Stand
- Bolt the roll-stand base to the machine through its base-plate holes.
- Level the stand: set the roll axis parallel to the machine idlers and square to web travel, with no tilt to either side. Check it with a machine square or a tram rod — whichever you have.
- Slide the moving carriage by hand through its full travel on its linear bearings. It should move smoothly end to end with no binding, notching, or stiff spots. If it binds, clean and re-lubricate or replace the linear bearings before you fit the actuator.
Retrofitting an existing stand?
- Reuse your existing roll-stand carriage and linear bearings — the moving structure stays.
- Replace the controls and the actuator: the old actuator and its drive come off, and the Roll-2-Roll controller, sensor, and actuator go on. Before you remove the old actuator, sketch or photograph how it attaches at both ends and note its fully-retracted and fully-extended positions — the new actuator matches that geometry and stroke.
- The rest of the install is identical to a new stand.
Mount the Actuator
- Match the actuator to the stand's mount before you install it: a fixed (-RF) structure takes an LHS-RF actuator — LHS is the only family offered with a fixed mount. A floating (-TG) structure takes a floating-mount actuator sized to the load — RLA for heavy rolls (the unwind/rewind default), BLA for intermediate loads and wide webs needing 6 in of stroke or more, or LHS-TG for small loads.
- Bench-test the actuator before you mount it. Connect its cables to the controller, apply power, and jog it end to end from the operator interface. It should travel smoothly the full stroke. If it doesn't move or it stalls, re-check the cabling and the supply before you commit it to the machine.
- Floating (-TG) mount — connect the front rod eye to the moving carriage and the rear spherical bearing or clevis to the stationary base. Add an anti-rotation feature at the spherical-bearing end so the actuator body can't spin, and let the pins carry the rotation so the actuator self-aligns as the stand moves.
- Fixed (-RF) mount — fasten the mounting plate so the actuator's linear motion is exactly in line with the carriage travel, and apply thread-locker to any fastener screwed directly into the actuator.
- Check the alignment — jog the stand slowly across its full travel and watch it move without struggling or binding. If it fights at any point, loosen the mounts, re-square the actuator to the carriage, and re-check.
- Match the stroke to the stand travel — confirm the actuator's fully-retracted and fully-extended positions coincide with the carriage's travel extremes, and center the stroke. If the actuator over-travels the stand, reduce the digital stroke length in the controller; if it under-travels, add mechanical stops.
- Install the servo-center proximity sensor (SKU 7-140004) so it switches exactly at mid-stroke — with the stand centered, position it to see metal within 2 mm for one half of the travel and clear space for the other half. Jog through mid-stroke and confirm its LED toggles on and off right at center; the controller uses this transition to find the actuator's home position during commissioning.
- Connect the RC-050A regeneration clamp into the actuator drive circuit as shown in the wiring diagram — a heavy roll decelerating or reversing drives regenerated energy back into the drive, and the clamp dissipates it.
Mount the Motor Driver Box
- Mount the MC QD motor-driver box on the machine, close to the roll stand and actuator. It has its own enclosure, so it does not need to sit inside another cabinet.
- Keep the box within about 10 m of the actuator — that is the reach of the motor-communication cable (SKU 21223) carrying the RS485 link from the controller.
- Mount the 24/48 VDC driver power supply (SKU PS-10001) near the driver box — the high-current driver takes its own supply through the driver-power cable (SKU 21219), separate from the controller's 24 VDC.
- The RC-050A regeneration clamp installs in line between the 24/48 VDC supply and the MC QD driver's power input — supply feeds the clamp, and the clamp feeds the driver, not a side branch off either one.
- The RC-050A clamp is DIN-rail mounted — clip it to the rail next to the 24/48 VDC supply so the in-line run from supply to clamp to driver stays short.
Choose the Sensor Location and Mount the Sensor
- **Unwind stand:** mount the sensor in the first free span downstream of the idler that follows the roll — it has to read the web after the shifting stand has moved it, not before.
- **Rewind stand:** mount the sensor just upstream of the fixed idler ahead of the rewind stand, so it reads the edge before the web winds on. Mount it on the rewind frame itself, not the machine frame — rewind guiding chases the web, and the sensor must move with the stand to hold the relative position between the web and the rewind roll.
- Clamp the sensor bracket to its rail, but don't fully tighten it yet.
- Set the working distance from the sensor face to the web to 5–15 mm (0.2–0.6 in).
- Keep everything at least 150 mm (6 in) behind the web clear in the sensor's view — the camera-style sensor can otherwise pick up background objects.
- Guiding a shiny, metallic, or clear web? Tilt the sensor a few degrees toward the web so its angled light returns to the lens, then re-check the working distance.
- Tighten the bracket.
Pre-Power Mechanical Checks
- Do these with the power off, before you commission. With the actuator mounted, don't force the stand by hand — you can back-drive the actuator.
- Confirm the actuator is mounted in line with the carriage travel and its retracted and extended limits line up with the stand's travel extremes.
- Confirm the servo-center proximity sensor is installed and its LED changes state as the carriage passes mid-stroke.
- Confirm the RC-050A regeneration clamp is connected in the actuator drive circuit per the wiring diagram.
- Confirm every cable is routed and strain-relieved, and that nothing is powered yet.
Reference Documents
Install the Sensor
Install the Sensor — Contrast Guiding
- Contrast guiding uses a single ODC white-light sensor over the contrast boundary (a coating edge, color change, or stripe), and needs a backup roller (any roller or dead bar) directly under the sensor to hold the working distance steady — a plane change reads as a contrast change.
- Any roller or dead bar works as the backup roller. Keep its wrap as small as possible so it doesn't change how the web runs off the stand.
- **Unwind stand:** the sensor stays fixed to the machine frame, but the backup roller mounts on the moving stand with the shifting idlers — the web's pass line then holds steady under the fixed sensor as the stand shifts and the roll diameter changes.
- **Rewind stand:** the opposite — the sensor rides the rewind frame, so the backup roller stays fixed to the machine. Read the web over the fixed idler (or a fixed dead bar) just ahead of the stand; the moving sensor holds its working distance over the fixed roller as the stand chases the web.
Wire the System
Configure & Verify
Power up the controller and commission the guide, one checked step at a time.
Contrast Guiding — Power Up and Commission
Commission single-sensor contrast guiding — teach the boundary, prove the high-thrust motion, then track it in automatic.
- Power on the controller. If it wakes in Automatic, switch to Manual — every step below runs from Manual.
- Set the sensor to contrast sensing.
- Teach the boundary. On the Operator → Sensor screen, enter teaching mode, pick the contrast mode from the on-screen icons, and use the left/right arrows to land on your boundary (a coating edge, color change, or stripe) in the live image. Save with the gear button — it turns red and a green box locks around the boundary. Until a valid feature is taught, the controller stays interlocked and won't enter Automatic.
- Check the jog direction. Tap Jog Left, then Jog Right, and watch the roll stand. It should shift the way each button says. If it moves the opposite way, reverse Motor Polarity under Power User → Actuator → Motor Polarity, then jog again to confirm.
- Servo-center the actuator. Tap Servo Center and let the stand travel to its home position (half the actuator stroke each way). If it heads away from home, reverse Servo Center Polarity under Power User → Actuator → Servo Center Polarity, then servo-center again.
- Set the guide point. Tap Reset Guide Point to lock the target onto the boundary's current position. (To offset it, drag the guide-point bar and press Accept.)
- Switch to Automatic. The actuator now shifts the roll stand to keep the taught boundary on target. If it won't enter Automatic, the boundary isn't taught or isn't in view — re-teach at step 3.
- Check the correction direction. Nudge the web so the boundary moves off target. The stand should shift to bring it back. If it drives the boundary further off, reverse Error Polarity under Power User → Controller, then watch it correct again.
- Fine-tune the position. Still in Automatic, tap Jog Right (+) or Jog Left (−) to nudge the tracked boundary to the exact spot — about 0.25 mm (0.01 in) per tap.
- Prove the safety hold. Pull the boundary out of the sensor's view. The actuator should hold the stand at its last position (it won't recenter) until the boundary returns. When it holds, your unwind/rewind contrast guide is commissioned.
PLC Integration
Web guiding controllers support remote command via two routes: Industrial Ethernet PLC remote control, and the DIO option (discrete dry-contact inputs). Both allow a PLC or supervisory system to command guide mode and position without manual touchscreen interaction.
- Route 1 — PLC remote control (C(x) models): send auto mode on/off, jog, servo center, and guide-point commands over Industrial Ethernet (EtherNet/IP, PROFINET, EtherCAT)
- Route 2 — DIO option: discrete dry-contact 24 V NPN inputs for hard-wired remote on/off and mode switching — no Industrial Ethernet required; wired directly from PLC digital outputs or relay contacts
- Both routes can coexist — Ethernet for data and fine control, DIO for hard-wired safety/interlock inputs
- Lock on Lost Edge: when the web edge exits the sensor field of view during edge guiding, actuator motion is inhibited — prevents runaway
- Loss of Contrast Inhibit: for line/contrast guiding, actuator motion is inhibited if contrast is lost until the target feature is re-acquired
📄 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
- Intermediate Web Guide — Guide the web mid-machine with an intermediate web guide and LHS actuators
- Retrofit an Existing Web Guide — Upgrade a legacy or competitor web guide with Roll-2-Roll sensors and controllers
Learn More
- Unwind and Rewind Guides — Design and Installation Considerations
- How to Size an Actuator for Unwind/Rewind Web Guides
Need Help?
Email: experts@r2r.tech
Phone: +1-888-290-3215