What it is and what it does
The Siemens 6GT2821-7AC12 is an RF285R reader from the SIMATIC RF200 family, operating at 13.56 MHz with an RS232 serial interface. It reads and writes ISO 15693 and ISO 18000-3 transponders, with a typical read/write access time of 0.6 ms per byte. The reader is multitag-capable and achieves a maximum transfer rate of 26.5 kbit/s over the air interface. Range is adjustable via transmission power and depends on the transponder type, with a maximum of 550 mm. It supports one external antenna via a TNC connector, with antenna cable lengths from 3.3 m to 25 m. The RS232 interface can be extended up to 30 m. Power is supplied through an 8-pin M12 connector at 24 VDC nominal (21.6 to 26.4 V range), drawing 0.4 A typical, 0.5 A maximum. The housing is aluminum, silver/anthracite, rated IP65 for washdown environments. Operating temperature range is -20 to +55 °C, storage/transport -25 to +85 °C.
Mounting and integration
Mounts via 4x M4 screws, on 35 mm DIN rail, or on an S7-300 mounting rail. The enclosure measures 200 mm wide × 80 mm high × 140 mm deep. Shock resistance per EN 60721-3-7 Class 7M2 (300 m/s²), vibration 20 m/s². The RS232 interface and power share the same 8-pin M12 connector — confirm pinout against your cable assembly before wiring. The reader is suited for connecting to PC systems and operates with ISO 15693 transponders (MDS Dxxx family).