Integrating Existing Analog Sensors

No need to rewire

Many plants already have 4-20mA or 0-10V sensors installed and running (load cells, pressure transmitters, level potentiometers). The iGromi Bridge connects to that existing installation without replacing anything — it just listens to the signal in parallel.

Step 1: Identify the signal type

Check the sensor or transmitter datasheet:

• 4-20mA (current): The most robust standard for long distances (up to 300m without degradation). The Bridge must be wired in series with the current loop.
• 0-10V (voltage): Common on proximity sensors and potentiometers. Wired in parallel, without cutting the existing cabling.

Step 2: Series connection (4-20mA)

1. De-energize the current loop at the cabinet.
2. Open the loop at the point closest to the existing PLC or controller.
3. Wire the Bridge in series: the transmitter's positive goes into terminal AI-01 on the Bridge, and AI-GND to the negative/common.

Step 3: Parallel connection (0-10V)

1. Wire AI-01 to the sensor's signal output, and AI-GND to the negative/common.
2. There is no need to interrupt the signal going to the original equipment — the Bridge has high input impedance (>1MΩ) and does not load the circuit.

Step 4: Scaling in software

In the iGromi OS portal, go to Edge Devices > Analog Input:

1. Select the physical range (e.g. 4-20mA).
2. Define the engineering range (e.g. 0 to 100 PSI, or 0 to 5000L for a tank).
3. iGromi OS linearly interpolates the raw signal into the real value and publishes it as a numeric tag in the Unified Namespace.

Note: If the sensor has a non-linear range (thermocouples, certain flow meters), a point-by-point calibration table is available on the same screen.