There are two 6704 cards and two 6713 cards in my PXI.
First I set channel 1(TPS) & 2(MAP) of one 6704 as 1.6V and 2.7 V and I got the exact value at the product ,
Then I set PXI 6713 waveform from 100rpm to 2000rpm , measure the output of 6704 by an oscillograph, the voltage output has been influenced obviously, and the measured values at the product as follow.
(CH1)TPS (CH2)MAP
Set TPS to 1.6V, MAP to 2.7V 1.596 2.695
Set 6713 to 100RPM, 1.591 2.691
500RPM, 1.54 2.64
900RPM, 1.535 2.634
1200RPM, 1.53 2.63
1400RPM, 1.527 2.627
1600RPM 1.524 1.665
1800RPM, 1.521 2.621
2000RPM, 1.518 2.618
Here I want to ask why does the output of 6713 influence 6704 output so greatly?