4-20mA Connector

Integrate third-party sensors seamlessly into monitoring

The Didactum 4-20mA connector is a key component for professional server room and infrastructure monitoring. With this connector, any analog sensor that outputs a 4-20mA current signal can be integrated directly into the network-based monitoring of a Didactum Monitoring System. This makes it possible to centrally capture and evaluate a wide range of measured values such as temperature, humidity, pressure, fill level, or industrial process values.

The connector is manufacturer-independent: any standard 4-20mA transmitter or sensor on the market can be connected and individually scaled via the web interface, regardless of which manufacturer produced the original sensor.

Connector overview

The connector is intentionally simple in design: on one side is the output to the monitoring system, and on the opposite side is the input for the connected 4-20mA sensor.

Connection and commissioning

Installation is straightforward and can easily be added to existing systems.

The connector is connected via its RJ-11 cable to a free analog sensor port (A1…A8) of the Didactum Monitoring System. After connection, the system automatically detects the connector and makes it available for configuration in the web interface. On the input side, the 4-20mA output of the third-party sensor is connected to the two terminals; for two-wire (loop-powered) transmitters, the sensor is powered directly through the same current loop.

In the web interface, you can then assign a name to the sensor, define the type of measuring device connected, and set individual thresholds for warnings and alarms.

Measurement scaling in the web interface

Because a 4-20mA signal initially provides only a current value, this value must be converted into the actual physical measurement value in the monitoring system.

For this purpose, a conversion formula is stored in the web interface that maps the measured current range (4 to 20 mA) linearly to the actual measuring range of the connected sensor—for example, 4 mA = 0 °C and 20 mA = 100 °C for a correspondingly scaled temperature sensor, or 4 mA = 0 bar and 20 mA = 10 bar for a pressure sensor. Once this formula has been stored, the system displays the correct measured value directly in the relevant physical unit, including the desired thresholds and alarms.

Measuring range and technical data

The maximum distance of 50 meters applies to the central unit or to a connected sensor expansion unit. The connector’s power consumption is approximately 100 mW.

Typical use cases

The 4-20mA connector can be used to centrally capture and evaluate a wide variety of measured values.

• Server room monitoring: integration of analog smoke detectors, temperature sensors, and humidity sensors for reliable early fire detection and temperature monitoring
• Critical infrastructure monitoring: integration of sensors for fill level, pressure, leaks, or access control in utilities and data centers
• Access control: integration of sensors used to monitor who is present in critical company areas
• Early fire detection: integration of smoke detectors and temperature sensors, combinable with humidity or leak sensors
• Remote monitoring: centralized acquisition of all measurement data over the network, with forwarding to higher-level management systems if required
• Industrial automation: monitoring of processes with current-loop-based sensors in production lines and machines

Why this connector is the right choice

What is included

Please check the contents upon receipt for completeness and report any missing or damaged parts to your supplier immediately.

• Didactum 4-20mA connector1 piece

More about the 4-20mA connector

Frequently asked questions