SR21 Slot Photoelectric Sensors - DATALOGIC

SR21 Slot Photoelectric Sensors - DATALOGIC

The SR21 series slot photoelectric sensors are precision optoelectronic devices designed for high-speed detection in automated processes. With a narrow 2mm slot width, these sensors deliver exceptional 12-bit resolution (4096 steps), ensuring reliable detection of small targets like labels, marks, or holes. The switching frequency reaches up to 25 kHz, with a response time as low as 20 µs, making them ideal for fast-moving production lines. The SR21-IR model uses infrared emission for general-purpose detection on continuous surfaces, while the SR21-RG model features dual red and green emissions for contrast-based applications, such as detecting print register marks on transparent films. Setup is simplified with teach-in and dynamic setting modes, allowing automatic or in-motion threshold calibration without stopping the process.

These sensors are primarily deployed in packaging lines, labeling machines, and paper or printing machinery. They excel in applications requiring precise detection of transparent or reflective materials, such as film webs, labels, or cardboard. The high resolution and fast switching make them suitable for counting, positioning, and synchronization tasks in automated packaging and converting equipment.

The main subcategories include the SR21-IR (infrared emission) and SR21-RG (red/green emission) models. Typical article codes follow the pattern "SR21-" followed by a suffix indicating emission type and optional features, such as "SR21-IR-2" or "SR21-RG-2". These sensors are available with cable or connector outputs, and some variants include adjustable sensitivity or IO-Link communication for advanced diagnostics.

At Electric Automation Network, we provide these sensors with real-time pricing and express worldwide shipping. Our team of specialized engineers offers personalized technical support to help you select the right model for your application, including documentation and setup guidance.