PID(INPUT 4-20mA OUTPUT 4-20mA)
HELLO
I AM WORKING ON A APPLICATION WHERE I HAVE TO CONTROL A FURNACE TEMERATURE WITH THYRISTOR CONTROLLED HEATER(4-20mA).
I AM USING A THERMOCOUPLE TRANSMITTER WHICH HAS A 24 VDC AUX SUPPLY AND 4-20mA OUTPUT(FOR TEMPERATURE FEED BACK). WHEN I MEASURE WITH MULTIMETER TRANSMITTER IS SHOWING CORRECT mA OUTPUT. BUT WHEN I CONNECT TRANSMITTER (+) TO CH1 AND (-) TO GND IT IS SHOWING 1.434 mA AND NOTHING CHANGE WITH TEMERATURE.
I remember having a similar issue where the ma reading didn't change.
It was fixed by putting
Indio.setADCResolution(16); // Set the ADC resolution. Choices are 12bit@240SPS, 14bit@60SPS, 16bit@15SPS and 18bit@3.75SPS.
in the setup code.
Hello,please submit code sample.
I am quite sure nothing is wrong in the hardware, I don't know if your test with multimeter is valid after all when connected to input bias.
If you load Industruino sample program you can see readings on display and check actual readings
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| Asked: 12/6/16, 2:39 PM |
| Seen: 3333 times |
| Last updated: 12/6/16, 3:59 PM |
i connect multimeter in series with ch1. multimeter and analog input showing same mA value.