HOBO U30 Ethernet Data Logger
- Web-based data access via Ethernet communications
- Plug-and-play smart sensors enable rapid deployment
- Double weatherproof, tamperproof enclosure for harsh environments
- Alarm capabilities via text, e-mail
- Optional analog inputs with sensor excitation
- HOBOlink for viewing data and system configuration via the web
- Scheduled data delivery from HOBOlink to email or FTP
- Includes relay that can be activated on user-defined alarm conditions
In what environment does this data logger operate?
This data logger operates in indoor and outdoor environments.
What measurements does this data logger support?
The U30-ETH data logger supports the following measurements: 4-20mA, AC Current, AC Voltage, Air Velocity, Amp Hour (Ah), Amps (A), Barometric Pressure, Carbon Dioxide, Compressed Air Flow, DC Current, DC Voltage, Differential Pressure, Gauge Pressure, Kilowatt Hours (kWh), Kilowatts (kW), Leaf Wetness, Light Intensity, Power Factor (PF), Pulse Input, Rainfall, Relative Humidity, Soil Moisture, Temperature, Volt-Amp Reactive, Volt-Amp Reactive hour, Volt-Amps (VA), Volts (V), Water Flow, Water Level, Watt Hours (Wh), Watts (W) and Wind
The country of origin for this product is the United States. To see the full specifications for this product, please see our product manual found under the documentation tab if available.
Normal operating range: -20°C to 40°C (-4°F to 104°F)
Extended operating range: -40 to 60°C (-40 to 140°F) - see "Rechargeable Battery service Life" for impact of operations in Extended Operating Range.
Sensor Inputs: 5 standard; option to expand to 10
Smart Sensor Compatibility: Compatible with most Onset smart sensors
Data Channels: Maximum of 15 (some sensors use more than one data channel)
Alarm Output Relay: Can be configured to be activated, deactivated or pulsed on user-defined sensor alarms. The relay can be configured as normally open or normally closed, and is rated for 30 V and 1 amp max.
Expansion Slot: One expansion slot is available for factory-installed expansion port.
Local Communication: Full Speed USB via USB mini-B connector
Size: 17.8 H x 11.7 D x 19.3 W cm (7.0 H x 4 .6 D x 7.6 W inches)
Weight: 2 kg (4 lbs 10 oz)
Materials: Outer Enclosure: Polycarbonate/PBT blend with stainless steel hinge pins and brass inserts
Inner Enclosure: Polycarbonate with brass inserts
U-Bolts: Steel with zinc dichromate finish
Gaskets: Silicone rubber
Cable entry channel: EPDM rubber
Cable entry bars: Aluminum with ABS plastic thumb screws
Data Storage Memory: Nonvolatile flash data storage, 512K bytes local storage
Memory Modes: Stop when full, wrap around when full
Operational Indicators: Up to seven (depending upon options) status lights provide basic diagnostics
Logging Interval: 1 second to 18 hours, user-specified interval
Battery Type: 4 Volt, 10 AHr Rechargeable sealed lead-acid
Rechargeable Battery Service Life: Typical 3–5 years depending upon conditions of use. Operation within the extended operating range (but outside the normal range) will reduce battery service life.
Time Accuracy: 0 to 2 seconds for the first data point and ±5 seconds per week at 25°C (77°F)
Environmental Rating: Weatherproof enclosure, tested to NEMA 6. (Requires proper installation of cable channel system)
Mounting: 3.8 cm (1.5 inch) mast or wall mount
Enclosure Access: Hinged door secured by two latches with eyelets for securing with user-supplied padlocks
Alarm Notification Latency: Logging interval plus 2–4 minutes (typical). Onset is not responsible for failed connections or undelivered mail/text messages.
Alarm Output Relay: One relay contact closure can be configured as normally open, normally closed, or pulsed.
Voltage: t30 V Current: 1 amp max.
Sensor Network Cable Length: 100 m (328 ft) maximum
External Power: External power is required. The system optionally accepts the following Onset solar panels:
- SOLAR-1.2W
- SOLAR-3W
- SOLAR-6W
Alternatively it accepts an AC power adapter:
- AC-U30
Ethernet:
Interface: Ethernet 10Base-T or 100Base-TX (Using external RJ45 Jack)
Encryption: 256-bit AES Rijndael encryption
RJ 45 Jacks: 1
Optional Analog Sensor Port Specifications
Input Channels: Two, single-ended
Field Wiring: Two- or three-wire via screw terminals on detachable connector, 16–24 AWG.
Replacement detachable connectors: Part of spares kit, Part No. A-FS-CVIA-7P-1
Input Range: User-configurable: 0–20 mA DC, 0-2.5 VDC, 0-5 VDC, 0-10 VDC, or 0–20 VDC
Minimum / Maximum Input Voltage: 0 / 24 VDC
Minimum / Maximum Input Current: 0 / 24 mA DC
Minimum Current Source Impedance: > 20 KΩ
Accuracy: ± 0.25% of FSR from 50mV to FSV
ADC Resolution 12 bits
​Excitation Power: Switched 12 VDC, up to 50 mA; user-selectable warm-up from 5msec to 2 minutes

The following are associated resources for this product. In general users of this product can gain insight into its possible use by utilizing the resources below.
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Detailed Specifications
HOBO U30 Ethernet Data Logger
Normal operating range: -20°C to 40°C (-4°F to 104°F)
Extended operating range: -40 to 60°C (-40 to 140°F) - see "Rechargeable Battery service Life" for impact of operations in Extended Operating Range.
Sensor Inputs: 5 standard; option to expand to 10
Smart Sensor Compatibility: Compatible with most Onset smart sensors
Data Channels: Maximum of 15 (some sensors use more than one data channel)
Alarm Output Relay: Can be configured to be activated, deactivated or pulsed on user-defined sensor alarms. The relay can be configured as normally open or normally closed, and is rated for 30 V and 1 amp max.
Expansion Slot: One expansion slot is available for factory-installed expansion port.
Local Communication: Full Speed USB via USB mini-B connector
Size: 17.8 H x 11.7 D x 19.3 W cm (7.0 H x 4 .6 D x 7.6 W inches)
Weight: 2 kg (4 lbs 10 oz)
Materials: Outer Enclosure: Polycarbonate/PBT blend with stainless steel hinge pins and brass inserts
Inner Enclosure: Polycarbonate with brass inserts
U-Bolts: Steel with zinc dichromate finish
Gaskets: Silicone rubber
Cable entry channel: EPDM rubber
Cable entry bars: Aluminum with ABS plastic thumb screws
Data Storage Memory: Nonvolatile flash data storage, 512K bytes local storage
Memory Modes: Stop when full, wrap around when full
Operational Indicators: Up to seven (depending upon options) status lights provide basic diagnostics
Logging Interval: 1 second to 18 hours, user-specified interval
Battery Type: 4 Volt, 10 AHr Rechargeable sealed lead-acid
Rechargeable Battery Service Life: Typical 3–5 years depending upon conditions of use. Operation within the extended operating range (but outside the normal range) will reduce battery service life.
Time Accuracy: 0 to 2 seconds for the first data point and ±5 seconds per week at 25°C (77°F)
Environmental Rating: Weatherproof enclosure, tested to NEMA 6. (Requires proper installation of cable channel system)
Mounting: 3.8 cm (1.5 inch) mast or wall mount
Enclosure Access: Hinged door secured by two latches with eyelets for securing with user-supplied padlocks
Alarm Notification Latency: Logging interval plus 2–4 minutes (typical). Onset is not responsible for failed connections or undelivered mail/text messages.
Alarm Output Relay: One relay contact closure can be configured as normally open, normally closed, or pulsed.
Voltage: t30 V Current: 1 amp max.
Sensor Network Cable Length: 100 m (328 ft) maximum
External Power: External power is required. The system optionally accepts the following Onset solar panels:
- SOLAR-1.2W
- SOLAR-3W
- SOLAR-6W
Alternatively it accepts an AC power adapter:
- AC-U30
Ethernet:
Interface: Ethernet 10Base-T or 100Base-TX (Using external RJ45 Jack)
Encryption: 256-bit AES Rijndael encryption
RJ 45 Jacks: 1
Optional Analog Sensor Port Specifications
Input Channels: Two, single-ended
Field Wiring: Two- or three-wire via screw terminals on detachable connector, 16–24 AWG.
Replacement detachable connectors: Part of spares kit, Part No. A-FS-CVIA-7P-1
Input Range: User-configurable: 0–20 mA DC, 0-2.5 VDC, 0-5 VDC, 0-10 VDC, or 0–20 VDC
Minimum / Maximum Input Voltage: 0 / 24 VDC
Minimum / Maximum Input Current: 0 / 24 mA DC
Minimum Current Source Impedance: > 20 KΩ
Accuracy: ± 0.25% of FSR from 50mV to FSV
ADC Resolution 12 bits
​Excitation Power: Switched 12 VDC, up to 50 mA; user-selectable warm-up from 5msec to 2 minutes