WTU

WTU Wireless Transmission Unit for Sensors

Simplify your setup. Connect devices wirelessly. Transmit data securely.

Long-distance wireless communication via ISM band

Battery-powered portable version for mobile setups

Available as stationary or portable version

Supports Modbus RTU protocol

AES 128-bit encryption for secure data transmission

Scalable solution for multi-point monitoring

Quick configuration with S4C-WTU mobile app

Repeater mode for extended wireless range

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The WTU (Wireless Transmission Unit) replaces traditional wiring with a robust wireless link between Modbus master and slave devices. It is the ideal solution for transmitting data across compressed air networks where cabling is impractical or costly.

Available in Three Models

Designed for flexible use, the WTU is available in three models:

WTU-S for stationary installations
WTU-P with integrated battery for portable use
WTU-PM for mobile master devices like the S551

With plug and play connectivity, standard connectors and encrypted transmission, the WTU ensures secure and reliable communication between sensors, data loggers and gateways—even over long distances or across buildings.

The WTU can act as a Master, Slave or Repeater, allowing users to tailor the wireless setup to any site condition or infrastructure layout.

Advanced Wireless Integration

SUTO’s S4C-WTU app makes device setup intuitive and mobile-friendly. View system status, configure wireless and Modbus settings, or run signal strength tests—all directly from your phone. The guided setup reduces installation time and simplifies scaling as the monitoring system grows.

With multi-sensor support per WTU slave, and up to 16 devices per master, the WTU ensures complete coverage of your measurement points.

Distributed Compressed Air Networks: Connect sensors in remote or hard-to-wire locations
Industrial Plants: Bridge Modbus communication between buildings
Mobile Measurement Setups: Use the WTU-P to transmit data wirelessly from portable instruments
System Upgrades: Replace cables in existing installations to avoid production interruptions
Wireless Extensions: Use the WTU as a repeater to extend range or overcome noise interference

GENERAL DATA
Frequency Wireless Communication	470-510 MHz (CN470) 863-870 MHz (EU868) 915-928 MHz (US915)
Housing material	Plastic casing
Protection class	IP65
LED indicator	1 x LED
Operating temperature	0 ~ 50 °C
Humidity	<90%RH, no condensation
Dimensions	WTU-S & WTU-PM: 80 x 60 x 30.3 mm WTU-P: 130 x 90 x 40 mm
Weight	WTU-S & WTU-PM: 120 g WTU-P: 470 g
ELECTRICAL DATA
Power input	WTU-S & WTU-PM: 18...28 VDC/0.5A WTU-P: 18...28 VDC/1A
Power output	WTU-S & WTU-PM: 18...28 VDC/0.5A WTU-P: 24 VDC/0.5A
Power consumption	WTU-S&WTU-PM: <= 0.3 W WTU-P: <= 0.5 W
Battery	WTU-P: Lithium ion battery, 3500 mAh, 11.1 V
INTERFACE
LED	Constant green: Power on Blinking green: Receiving data Constant red: Error Blinking red: Transmitting data
Status screen	WTU-P: Battery level display
Connector	RS485 (Modbus/RTU)
Transmission method	Transparent data transmission
Encryption technology	AES 128-bit encryption for secure data transmission