Hardware
Industrial-grade controllers and encoders for reliable roll tracking on any production line
Industrial-grade controllers and encoders for reliable roll tracking on any production line
RollTagger's preferred hardware platform is the RevPi Connect 4 — a robust, DIN-rail mounted industrial controller based on the Raspberry Pi Compute Module 4. Designed specifically for industrial automation, it provides a low-cost, high-reliability edge computing solution that fits naturally into any control cabinet.
Its open architecture and Linux-based OS means RollTagger can be deployed and updated remotely with minimal on-site commissioning. Made in Germany by KUNBUS GmbH.
| Specification | Detail |
|---|---|
| Processor | Broadcom BCM2711, quad-core Arm Cortex-A72 |
| Clock Rate | 1.5 GHz |
| LAN Ports | 2× Ethernet |
| USB Ports | 2× USB-A 3.2 |
| RS485 | 1× RS485 (for encoder / Modbus) |
| Onboard I/O | 1× relay output, 1× digital input |
| Power Supply | 24 V DC |
| Mounting | DIN rail (35 mm) |
| Protection | IP20 |
| Origin | Made in Germany |
| Certifications | CE, UKCA, UL, AWS IoT Qualified |
The RevPi DIO digital I/O expansion module connects directly to the RevPi Connect 4 via the PiBridge plug, adding 14 digital inputs and 14 digital outputs for machine interfacing.
RollTagger uses the DIO to interface with rewinder and unwinder machine signals — including splice detectors, turret index signals, vision system outputs, and automated stop/start controls.
| Specification | Detail |
|---|---|
| Digital Inputs | 14 |
| Digital Outputs | 14 |
| Connection | PiBridge (plug-in expansion) |
| Power Supply | 24 V DC |
| Protection | IP20 |
| Compatible With | RevPi Connect 4, Connect 5, Connect S/SE |
| Origin | Made in Germany |
RollTagger uses the BRT RS485 Modbus RTU absolute rotary encoder — a compact, industrial-grade magnetic encoder with power-off memory. Fitted to the rewind spindle, it counts rotations precisely. Combined with a linear encoder on the web, RollTagger calculates roll diameter and material thickness in real time.
Available in single-turn and multi-turn variants with multiple shaft sizes, making it easy to fit onto any rewinder or unwinder spindle.
| Specification | Detail |
|---|---|
| Technology | Absolute magnetic encoder |
| Interface | RS485 |
| Protocol | Modbus RTU |
| Resolution | Up to 17-bit (131,072 steps/rev) |
| Single-turn accuracy | < ±0.025° |
| Repeat accuracy | < ±0.05° |
| Max speed | 5,000 RPM |
| Supply voltage | 5 – 24 V DC |
| Baud rate | 9,600 – 115,200 (default 9,600) |
| Power-off memory | Retains position — no battery needed |
| Protection | IP54 |
| Temperature | −40 °C to +85 °C |
| Shaft options | 4 mm, 6 mm, 8 mm, 10 mm solid; blind hollow |
| Multi-turn range | Single-turn up to 21,600 turns |