The Siemens 3RK1904-3AB01 is an AS-Interface Analyzer V2 — a portable diagnostic tool for commissioning and troubleshooting AS-i networks up to V2.1, including ASIsafe evaluation and a measurement wizard. It captures and stores up to 256 000 AS-Interface message frames, which is the kind of buffer depth you need to catch intermittent faults on a busy safety-related AS-i line without babysitting the tool. The unit is powered directly from the AS-Interface cable, drawing 70 mA, so no separate supply rail is needed. It connects to the AS-i network via removable screw-type terminals and to a PC for analysis through a 9-pole D-Sub RS232 interface. A trigger input (24 V) and trigger output (TTL) let you synchronize captures with external events — useful for correlating a field-device dropout with a specific machine cycle.
At 150 mm wide, 90 mm deep, and 30 mm tall, the analyzer is sized for a service case — it ships with a foam inlay, screwdriver, D-Sub data cable, and RS232 USB adapter. The IP20 rating means it belongs on a bench or in a panel with controlled access, not on a washdown floor. Operating range is 0 to 55 °C, storage -25 to +70 °C, so it survives a hot service vehicle or unheated storage shed. The included PC software V1.3.7.0 runs on Windows 7 through Windows 11, plus XP and Vista. System requirement is an IBM-compatible PC 80486 or higher — effectively any modern Windows machine. EMC compliance is to EN50081-2 and EN61000-6-2, so it won't radiate noise into adjacent control gear in an industrial panel.