VT420 current loop 4-20mA converter (fue

Connecting 3rd party 4-20mA current loop sensors to Vutlan monitoring units

Analog signals, where information about the process is transmitted via varying amounts of voltage or current, are the predominant type of input in industries requiring process control today. Of all possible analog signals that can be used to transmit process information, the 4-20 mA loop is, by far, the dominant standard in the industry.


  • Connecting industrial sensors to Vutlan monitoring systems for monitoring and control
  • Measuring fuel level or other liquid in a tank
  • Measuring the concentration of CO2 or other gases
  • Connecting pressure transducers for measurement of gases or liquids.
  • Monitoring pH change for analysis of water or soil quality
  • Monitoring and controlling other industrial sensors or devices

Components of a 4-20 mA Loop

a) 4-20mA current loop sensor

VT420 can convert signals from any 4-20mA current loop sensor. Depending on the source of current for the loop, devices may be classified as active (supplying or "sourcing" power) or passive (relying on or "sinking" loop power).

b) External power supply

If the sensor is passive, it requires an external current source. To help You choose the power supply voltage and amperage please read: "VT420 Technical Documentation".

c) VT420 / 4-20mA converter

The converter of direct current 4-20mA is used for measurement of constant current on 4-20mA from different sensors and converting data into the format of IP monitoring system. The sensor is connected to the Vutlan monitoring system by RJ11 / RJ12 cable and detected by the system automatically.

c) Vutlan monitoring system

The system interface allows you to assign the sensor and to introduce the function data conversion.

Example 1: industrial water level sensor is monitored by VT335

VT420 current loop 4-20mA converter (fue

a) Sensor's data is sent to Network Monitoring Center using SNMP traps.

b) Monitoring unit has built-in logic schemes to send E-mail and SMS messages in case of emergency.

c) Technician monitors the sensor using the built-in web interface

Example 2: three pressure transmitters are monitored by VT335

VT420 current loop 4-20mA converter (fue

Web Interface Menu Panels

Below are some of the screenshots showing four easy steps to tune the "VT420 / converter" for usage with a 4-20mA sensor.

VT420 in system tree.jpg

1: VT420 is detected by the system

VT420 settings (4-20ma current loop).jpg

2. Open VT420 configuration

VT420 settings adjusted (4-20ma current

3. Tune VT420 and save

VT420 in system tree configured.jpg

4. Sensor is tuned

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