The Siemens SIMATIC RF250R (6GT2821-5BC32) is an ultra-compact HF RFID reader with an IO-Link V1.1 interface. Measuring just 50 × 50 × 30 mm and weighing only 14 g, it is designed for identification tasks in space-constrained environments such as tool holders, machine fixtures, and small assembly stations. The reader has no integrated antenna — instead, it connects to external antennas from the Siemens ANT series (ANT 1, ANT 3, ANT 3NO, ANT 8, ANT 12, ANT 18, ANT 30), allowing the antenna to be positioned independently from the reader for optimal read geometry. Connection to an IO-Link master enables seamless integration into PROFINET and PROFIBUS networks via TIA Portal.

How Does the External Antenna System Work?

The RF250R requires a separate external antenna connected via cable. Supported antennas in the Siemens ANT series offer varying read ranges and form factors — from small rod antennas (ANT 1) to larger compact antennas (ANT 8, ANT 12) and extended-range antennas (ANT 18, ANT 30). This architecture separates the reader electronics from the RF field, enabling installation where the reader body is tucked into a confined space while the antenna is positioned for optimal transponder detection at the identification point. The achievable read range depends on the selected antenna and transponder combination, typically up to 65 mm with the larger antennas.

How Does the IO-Link Interface Work on the RF250R?

The IO-Link V1.1 connection provides 230 kbit/s (COM3) point-to-point communication with 32 bytes of input and output process data. The reader connects via a standard M12 4-pin connector with a maximum cable length of 20 m to the IO-Link master. Power is supplied at 24 V DC (20.4–28.8 V) with typical current consumption of 50 mA through the IO-Link connection. Configuration, commissioning, and diagnostics are managed within TIA Portal for a unified engineering workflow.

What RFID Standards and Transponders Are Supported?

The RF250R operates at 13.56 MHz using ISO 15693 and ISO 18000-3 standards. It is compatible with the Siemens SIMATIC RF200 transponder range including MDS D100, D124, D126, D139, D160, D165, D200, D324, D339, D421, D424, D425, D426, D428, D460, D524, and D528 series. The maximum RF data transfer rate is 26.5 kbit/s. The reader processes one transponder at a time. A 3-color LED provides visual status for power (green), transponder presence (yellow), and error states (red flashing).

What Are the Mechanical and Environmental Specifications?

The RF250R measures 50 × 50 × 30 mm and weighs just 0.014 kg. It mounts directly on metal surfaces with no minimum clearance required. IP65 protection ensures complete dust-tight operation and resistance to low-pressure water jets. Operating temperature range is −25 °C to +70 °C. The reader is RoHS compliant.

Frequently Asked Questions

How does the RF250R differ from the RF260R?

The RF250R (50 × 50 × 30 mm, 14 g, IP65) is an ultra-compact reader requiring an external antenna, providing flexibility to position the reader and antenna independently. The RF260R (75 × 75 × 41 mm, 200 g, IP67) includes an integrated antenna in a single housing with up to 135 mm read range. Choose the RF250R for space-constrained installations and flexible antenna placement; choose the RF260R for a self-contained reader with longer read range and higher environmental protection.

Which external antenna should I choose for the RF250R?

Antenna selection depends on the required read range, mounting dimensions, and transponder type. ANT 8 and ANT 12 are general-purpose compact antennas suitable for most applications. ANT 18 and ANT 30 provide extended range for larger read distances. ANT 1 and ANT 3 are smaller rod-type antennas for very confined spaces. Refer to the Siemens SIMATIC RF200 system manual for detailed antenna specifications and transponder compatibility charts.