Sensor 4-20mA
€164.10
The galvanically isolated signal converter for 4-20 mA current loops
The HW group Sensor 4-20mA 1W-UNI is a galvanically isolated, RJ11-powered converter for external 4-20 mA probes. It includes a current source to power the external probe and is typically used to connect an industrial probe with a 4-20 mA interface (2-wire current loop, “Sink” type) to devices of the STE2, Poseidon2 or Ares family.
This allows almost any industrial sensor to be integrated – for example a pressure sensor, a CO₂ sensor or a tank level probe. The measured values are available via LAN or GSM/LTE; if the current falls outside the defined range, an e-mail or SMS is sent. Connection to SNMP- or Modbus/TCP-based remote monitoring systems is possible.
Industrial current-loop measurement on the 1-Wire-UNI bus
The sensor converts the 4-20 mA signal of the external probe into a measured value on the 1-Wire-UNI bus – even over current loops of several tens or hundreds of metres in length.
Input 4–20 mA
For “Sink”-type probes; accuracy 2 % of the full 4–20 mA range (at 25 °C), resolution 0.1 mA, measurement once per second.
Integrated current source
Powers the external 4-20 mA probe; an external 12–30 V DC supply at the sensor is required for this purpose.
Galvanic isolation
The 1-Wire-UNI bus is electrically isolated from the 4-20 mA input and from the external power supply.
2× RJ11 (1-Wire UNI)
Two RJ11 connectors allow further 1-Wire sensors to be daisy-chained on the same bus (max. 60 m total length from the active port).
8-point calibration
The measured value can be calibrated at 8 points on the characteristic curve and converted into other units (e.g. [m], [mm], [hPa], [ppm]).
Input protection
A fast-acting 63 mA fuse protects the input; maximum external voltage 30 V.
Individually selectable: without or with plug-in power supply
The Sensor 4-20mA 1W-UNI is available in two variants that differ in the power supply of the 4-20 mA probe.
Please note: The variants listed below must be selected above the add-to-cart button. Variant 1 does not include a power supply – the sensor requires an external 12–30 V DC supply for operation.
Variant 1
4 to 20 mA DC current converter. Electrically isolated, requires an external power supply to provide energy for the 4-20 mA probe. Connection via RJ11 1W-UNI.
Variant 2
4 to 20 mA DC current converter. Galvanically isolated, including plug-in power supply for the 4-20 mA probe. Connection via RJ11 1W-UNI.
How the Sensor 4-20mA 1W-UNI is constructed
The compact plastic housing measures approximately 65 × 80 × 30 mm and weighs about 200 g, with protection class IP23. The sensor is intended for industrial use and can be placed on a table or mounted on a wall. Operating conditions: −40 °C to +85 °C at 5–70 % RH (storage: −30 °C to +60 °C, 5–95 % RH).
2-pole terminal block (I+, I−)
This is where the external 4-20 mA probe is connected. The input powers the probe via the integrated current source and is protected by a fast-acting 63 mA fuse.
Hollow-plug socket for external supply
The external 12–30 V DC supply is connected via a hollow-plug socket (inner Ø 2.5 mm, outer Ø 6.3 mm, ground on the outer contact). Current consumption approx. 20 mA at 12 V. The external supply is electrically connected to the 4-20 mA input.
2× RJ11 (1-Wire UNI)
Two RJ11 sockets connect the sensor to the 1-Wire-UNI bus of a compatible device and allow daisy-chaining of additional sensors. The bus side is powered with 5 V (approx. 20 mA) via the RJ11 connector.
Galvanically isolated electronics
Galvanic isolation decouples the 1-Wire-UNI bus from the 4-20 mA input and the external power supply – this increases immunity to interference in industrial environments.
Technical data
- Input range: 4–20 mA (“Sink”-type probe), max. 30 V external voltage
- Accuracy: ±2 % of the full 4–20 mA range at 25 °C
- Resolution: 0.1 mA (one decimal place), measurement rate: once per second
- Standard display: [mA]; conversion to other units possible via the calibration software
- Input protection: fast-acting fuse, 63 mA
- External supply: 12–30 V DC
- Bus supply: 5 V via RJ11 (approx. 20 mA)
- Maximum distance on the 1-Wire-UNI bus: 60 m from the active port
- Calibration points: 8, number of values supplied: 1
- Galvanic isolation: yes (bus from the 4-20 mA input and from the external supply)
Adaptation to the connected probe
The setting is made directly in the sensor – this ensures that the correct values also appear in e-mails, SMS messages and the web interface.
- Calibration tool for MS Windows (1Wire HWg-UniCalibrator)
- Calibration at 8 different points on the characteristic curve
- Conversion of the measured value into an output unit such as [m], [mm], [hPa] or [ppm]
- Calibration with the 1W-UNI USB Calibrator (USB-RJ11 cable with software)
Connection to Poseidon2, Ares and other HW group devices
The sensor is connected via the 1-Wire-UNI bus to compatible HW group devices, where it is detected and configured.
- Poseidon2 devices, Poseidon 2250 and Poseidon 4002
- Ares devices (e.g. Ares 12 / 14) as well as STE2
- Provision of measured values via LAN or GSM; connection to SNMP- or Modbus/TCP-based systems
- E-mail or SMS alarm as soon as the current falls outside the defined range
Note on Ares devices: The internal battery of Ares devices does not supply 12 V DC. In the event of a power failure, the external 12–30 V supply of the sensor is therefore not backed up by the Ares battery.
For unpowered industrial sensors with a 0-20 mA output, HW group offers the Sensor 0-20mA 1W-UNI as an alternative.
Commissioning in a few steps
The sensor is detected and configured directly via the connected HW group device.
- Connect the 4-20 mA probe (Sink type) to the terminal block (I+, I−)
- Connect the external 12–30 V DC supply to the hollow-plug socket (Variant 2 includes a plug-in power supply)
- Connect the sensor via RJ11 cable to a compatible Poseidon2, Ares, Poseidon 2250, Poseidon 4002 or STE2 device
- Allow the sensor to be detected automatically on the connected device and configure it via its web interface
- Optional: perform calibration and unit conversion with the HWg-UniCalibrator
- Set thresholds and desired alarm types (e-mail, SMS)
Why the Sensor 4-20mA 1W-UNI is the right choice
Almost any industrial probe
Connects 4-20 mA Sink-type probes to Poseidon2, Ares and STE2.
Galvanically isolated
Bus, probe input and external supply are decoupled.
Integrated current source
Powers the external probe directly from the 12–30 V supply.
Long current loops
The current loop may be several tens to hundreds of metres long.
Calibratable
8-point characteristic curve and unit conversion directly in the sensor.
24-month warranty
According to the manufacturer with a 24-month warranty from the date of purchase.
Practical application examples
- Measuring the level in a tank (e.g. fuel)
- Measuring the concentration of CO₂ or other gases
- Connecting pressure sensors and pH sensors
- Integrating further industrial sensors into Poseidon2 or Ares systems
Practical example: A level probe with a 4-20 mA output is connected to the Sensor 4-20mA 1W-UNI on a diesel tank, which in turn is connected to a Poseidon2 device. After calibration, the device displays the level directly in metres. If the level falls below the defined value, the device sends an e-mail or SMS.
Frequently asked questions
What is the HW group Sensor 4-20mA 1W-UNI and what is it used for?
The Sensor 4-20mA 1W-UNI is a galvanically isolated converter that connects external industrial probes with a 4-20 mA output (Sink type) to the 1-Wire-UNI bus of Poseidon2, Ares and STE2 devices. It is used, among other things, for levels, gas concentrations, pressure or pH values.
What options are available?
There are two variants: Variant 1 (requires an external power supply, supplied without power supply) and Variant 2 (including plug-in power supply for the 4-20 mA probe). The desired variant must be selected above the add-to-cart button.
Which probes can be connected?
External sensors that are powered from the 4-20 mA current loop (Sink type) can be connected, for example CO₂ sensors, pressure sensors, pH sensors or tank level probes. For unpowered 0-20 mA sensors, the Sensor 0-20mA 1W-UNI is available as an alternative.
Does the sensor need its own power supply?
Yes. The sensor requires an external power supply of 12–30 V DC, from which the integrated current source powers the 4-20 mA probe. Variant 2 includes a matching plug-in power supply; for Variant 1 it must be obtained separately.
How long may the current loop be?
The 4-20 mA current loop can be several tens or hundreds of metres long. On the 1-Wire-UNI bus itself, a maximum total cable length of 60 m from the active port of the connected device applies.
Can I convert the measured value into other units?
Yes. With the calibration tool 1Wire HWg-UniCalibrator, the measured value can be calibrated at 8 points and converted into units such as [m], [mm], [hPa] or [ppm]. Conversion directly in the sensor ensures that the correct values also appear in e-mails, SMS messages and the web interface.
Can the sensor be operated on an Ares device?
Yes, the sensor can be connected to Ares devices (e.g. Ares 12 / 14). Note that the internal battery of Ares devices does not supply 12 V DC – the external supply of the sensor is therefore not backed up by the Ares battery in the event of a power failure.
Questions about the Sensor 4-20mA 1W-UNI?
Our support team in Germany provides free advice on selection, sensing technology and configuration.
- 4 to 20mA DC Current Transformer Electrically isolated
requires an external power supply (not included) - 4 to 20mA DC Current Transformer Galvanically isolated
Includes plug-in power supply for the 4-20mA probe
Bus Properties:
- Bus Type: 1Wire-UNI (RJ11)
- Compatible Devices: Poseidon2 xxxx, Ares xx, Poseidon 2250, Poseidon 4002, SiteMon5
- Connection: 2x RJ11 (sensors can be connected in series)
- Maximum Distance: 60m (total cable length from the active port)
- Galvanic Isolation: 1Wire-UNI bus is galvanically isolated from the 4-20mA input
Power Supply:
- Power Supply: External 12-30VDC power supply required
- Connection: Socket (inner ø 2.5 mm, outer ø 6.3 mm), GND on outer pin
- Galvanic Isolation: External power supply is galvanically connected to the 4-20mA input
Sensor Input:
- Connection: 2-pin terminal block (I+, I-)
- Supported Sensors: External sensors with 4-20mA DC current loop (sink type)
- Input Range: 4-20 mA (max. 30V external voltage)
- Input Protection: Fast-blow fuse - 63 mA
- Accuracy: 2% of the full 4-20mA range / 25°C
Sensor Output:
- Resolution: 1 decimal place
- Displayed Units: Standard [mA] (conversion to [m], [mm], [hPa], [ppm] possible)
- Measurement Period: Once per second
Environmental Conditions and Dimensions:
- Operating Conditions: -40 to +85 °C (-40 to +185 °F) / 5 to 70% RH
- Dimensions: 65 x 80 x 30 [mm]
- Weight: 200 g
Additional Features:
- Calibration: Calibration tool available for MS Windows
- Calibration Points: 8 different points on a curve
- Unit Conversion: Programmable conversion from input voltage [V] to output units
- Current Source: Integrated current source for external sensors
Monitoring devices
Other available sensors
Extension units
Accessories
DB9 LapLink Cable 2m A LapLink cable (also known as Lablink or null-printer cable) is a cable used to connect two computers directly via a cable connection. Housing: Plastic Type: Cable
Mounting Plate D Bracket for Ares and Poseidon2 Operating environment: -3°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 74 x 6 x 120 (W x H x D) / 58g Warranty: 24 months Wall mounting plate for Ares, Poseidon2 3266/68 and other products.
DIN-Rail Box Set A mounting kit for installing HW-group devices on a DIN rail. Applications and Use: Mounting kit for installing HW-group devices with metal housing on a DIN rail. Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 45 x 11 x 105 (W x H x D) / 22g
Mounting Kit Screw set for mechanical mounting Applications and Use: Screw set for mechanical fastening
Mounting Plate E- 1U Rack (cabinet) mounting plate, 1U mounting for HW-group Ares and Poseidon2 devices Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 127 x 45 x 94 (W x H x D) / 137g Warranty: 24 months Rack (cabinet) mounting plate, 1U mounting for HW-group Ares, Poseidon2 3266/3268 and other products.
Mounting Plate L DIN Rail DIN rail mounting plate for Ares, Poseidon2 3268, and other products. Features: Metal housing Wall mounting Applications and Use: Profiles for metal-encapsulated HWg devices for wall mounting. Dimensions: 150 x 120 x 45 (W x H x D) / 65g Warranty: 24 months
Mounting Kit for Poseidon2 4002 and HWg-SMS-GW3 Applications and Use: Mounting kit for Poseidon2 4002 and HWg-SMS-GW3 Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 136 x 45 x 16 (W x H x D) / 165g Warranty: 24 months
Rack Shelf 1U A versatile solution for easy mounting of HW-group devices in 1U racks. Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 485 x 44 x 104 (W x H x D) / 597g Warranty: 24 months Housing: Metal Type: Wall mounting This shelf makes it easy to use devices in racks. You can even combine different 1U products and sensors.
Software
Manufacturer information:
HW group s. r. o.
Rumunská 26
Prague, 120 00
Czech Republic
Phone: +420 222 511 918
Email: sales@hwg.cz
Responsible person:
Didactum® Security GmbH
Im Mühlenfeld 4
48163 Münster
Deutschland
Fon:
(+49) 250 19 71 63 54 / (+49) 171 33 11 577
Email: info@didactum-security.de
