Technical data sheet for the JUMO Wtrans receiver model 902931, a wireless measurement unit with Modbus RS485 interface.
The JUMO Wtrans Receiver 902931 is a universal receiver for JUMO wireless measurement sensors. It supports a Modbus‑enabled RS485 interface, can connect up to 16 probes, and provides up to four analog outputs (0‑20 mA or 0‑10 V) or two relay outputs. The device operates on AC 110‑240 V or AC/DC 20‑30 V and works in the ISM bands 868.4 MHz (EU/China) or 915 MHz (US, AU, CA, NZ).
The receiver includes a two‑line LCD, four configuration buttons, and LED status indicators. It can be mounted on a DIN‑rail (35 mm × 7.5 mm) and offers isolated communication ports, including RS485, TTL/RS232, and USB/TTL converters. Environmental ratings cover –20 °C to +50 °C operation, IP20 protection, and vibration resistance up to 1 g. This manual is written in Chinese.
| Maximum connected probes | 16 |
|---|---|
| Analog output channels | 4 (0‑20 mA or 0‑10 V) |
| Relay output channels | 2 (max 3 A AC 230 V) |
| Power supply voltage | AC 110‑240 V or AC/DC 20‑30 V |
| Operating frequency | 868.4 MHz (EU/China) or 915 MHz (US/AU/CA/NZ) |
| Maximum outdoor range | 300 m with 3 m antenna cable |
The receiver can connect up to 16 wireless measurement probes.
Model 902931/10 provides four analog outputs that can be configured for 0‑20 mA or 0‑10 V signals.
It can be powered from AC 110‑240 V (±10 % tolerance) or from an AC/DC source of 20‑30 V.
The receiver works in the ISM bands at 868.4 MHz (China/Europe) or 915 MHz (US, Australia, Canada, New Zealand).