MGL Avionics User Forum

Hi Rainier-

I think there is a problem using the programmable probe option- in the SIM at least (not tested yet in actual hardware)

• iEFIS G3 SIM V 1121 (fresh download)

• COOLANT channel set to programmable probe

• programmable probe set up in equal ascending steps 20C..160C between 1000..4000 ADC

• using a simple text special item picking up RDAC1 coolant temperature

• ramping the simulator RDAC coolant slider up/down, the display behaves as if an NTC sensor down in the lower 25% input range, not a linear progressive 0-5V sensor

• I have cycled through the coolant probe options in case there was a 1-off issue, but no joy

Remember it assumes a NTC probe of unknown characteristic - it wants to see the resistance (and thus voltage across the probe) decreasing with temperature.

That stuffs up my plans!
I had asumed it could also be configured as a general purpose 0-5V analog input using the programmable probe option to calibrate it.
Would be a nice option (hint!)

I found another way to skin the cat....
The current input was not being used, so I configured it to behave as a GP 0-5V input.
Zeroing current at sensor minimum and tweaking the current gain to give the desired full scale value at sensor maximum, you can use it as a GP analog input and link a display item to it.
The upper and low level warning and alarm thresholds also work fine- even with the low level values greater than zero.
Bingo!