Which Fibaro Controller should we use to read 4-20mA signal?

[berjdemerjian 0]

The majority of sensors (Pressure sensor, Voltmeter, Ampere-meter..) provide a 4-20mA output signal. Can we read such a signal with any Fibaro Controller?

[Dalle1985 16]

No, for some reason, Fibaro has opted only to support 0-10V sensors, which limits the possibilities quite a bit. I would have loved to see a HART interface so you can use all sorts of industrial sensors. But you will need a converter to go inbetween to convert the 4-20 mA signal to a 2-10V signal and then you MIGHT be able to read it using the Fibaro RGBW-module which supports active 0-10V input (meaning the sensor must have it's own powersource).

[UrSv 6]

In some cases using a simple 500 Ohm (or a bit smaller just in case) resistor works fine to convert the 4-20 mA signal into 2-10 V which then can be accounted for in the RGBW controller. In some cases the use of a resistor may cause problems but I would try that first. This is if your sensor can drive the 500 Ohm resistor and if not then you need a few more bits to make it work.

[Dalle1985 16]

Another solution is to use a module that doesn't speak zwave, but has a logging interface you can access from some sort of databasing application. I am using php scripts to collect data from a power meter with RS232 interface. Mine is from datel and cost about 300$ but it has 8 inputs, so you can use it for more than one sensor.

I don't use the data I collect in the HC2, but it is relatively simple, once you have the datasource to do a script that you can call from the HC2 and get data into the HC2 that way round. But it isn't nearly as elegant as just interfacing it directly with the box, I'll grant you that

[berjdemerjian 0]

Hello! 

 

Thank you for your Help.

 

Furthermore, I measured a 10V voltage on the RGBW INPUT Pins of the RGBW Controller with no Sensor connected. Seems that the Controller can power the sensor.

I am building circuit boards to normalize the output signal from sensors in the field to 0-10V. Some sensors are not linear. Wish we can normalize any input from within the Fibaro HC interface by entering a suitable equation.

Currently we can only provide the Min and Max Voltages with respect to Min-Max Level Indication.

 

0-10V Sensor Input Mode.

 

Regards,