These instructions are applicable only to pressure transducers with 4-20mA output. Pressure transducers with voltage output are supported, but require a different procedure. Please refer to the appropriate Zenseio user guide.

Pressure transducers that have current (4-20 mA) output can be connected only to GPI2 port.

1. Setup

1. Configure Device with ZenConfig Mobile App
   
1. Set VAUX voltage output to the excitation voltage required by your sensor. Example: 12V for Lefoo T2000.
2. Select “4-20mA” mode on GPI2 port.
   
3. Set settling time the sensor’s measurement / stabilization time. Example: 10 ms for Lefoo T2000. If unsure, use 1000 ms or higher.
4. For "Supply VAUX?", select "Yes".
   
5. 
   
   
2. Connect the Sensor (Wire color coding may differ between sensor models. Always refer to the specific sensor’s instruction manual)
1. Connect sensor's COM / ground (usually BLACK) wire to GND.
   
2. Connect sensor's positive / signal (usually RED) wire to GPI2.
3. Connect jumper wire between GPI2 and VAUX. This jumper is mandatory. It completes the current loop required for 2-wire 4–20 mA transmitters. Without this jumper, the reading will be 0 mA.
   
4. 
   
3. Verify Operation
   
1. Press the user button inside the device.
   
2. Wait approximately 1 minute.
   
3. Open ZenConfig → read NFC → Status page.
4. Check "Last GPI2 Reading". Expected value: between 4 mA (zero pressure) and 20 mA (full-scale pressure)
   
4. Troubleshooting if readings are incorrect:
1. Reading = 0 mA
   
1. Sensor disconnected
2. Missing VAUX → GPI2C jumper
   
3. VAUX not enabled for GPI2
   
2. Reading below 4 mA or above 20 mA
   
1. GPI2 mode not set to 4–20 mA
   
2. VAUX voltage too low
   
3. Settling time too short
   

1. Full-Scale Pressure Range = sensor’s maximum rated pressure (e.g., 100 PSI, 200 PSI, 10 bar)
   
2. Measured Current = sensor's reading in mA (e.g., 12 mA)
   
3. result is in the same units as Full-Scale Pressure Range

Example 1: PSI Sensor

Sensor range: 0–100 PSI

Measured current: 12 mA

pressure = (12 − 4) × 100 / 16

pressure = 8 × 100 / 16

pressure = 50 PSI

Result: 50 PSI

Example 2: Bar Sensor

Sensor range: 0–10 Bar

Measured current: 8 mA

pressure = (8 − 4) × 10 / 16

pressure = 4 × 10 / 16

pressure = 2.5 Bar

Result: 2.5 Bar

Notes:

1. Some pressure transmitters report in PSI, others in Bar.
2. Always use the unit specified by your sensor model.