One AI will affect another AI reading in two different charts

[newuserneedhelp]

Hi guys, I have a 2 questions to ask.

1. Is it possible for me to run 2 fpga at the same time in a RT VI???

2. I created 2 fpga, each consists of 1 different AI; and I created 1 fpga with consists of  the 2 different AI, but the result I got is not the same, it seems like the noise is higher in that of 2 AI, and the reading of 1 AI will affect the other AI reading( means when i touch the sensor of a AI1, the graph of the AI5 will change it as well). How can i solve this problem????

The following attachment is the fpga files i mentioned. The " 2AI in a FPGA" shows the 2 different graph that have the same reading pattern even though i touch one of the sensor only.

Thank you in advance.

[crossrulz · Accepted solution]

1. What are you running your RT and FPGA code on?

2. That sounds like you are seeing ghosting, which is a problem when any muxed AI.

[newuserneedhelp]

1. When i created the fpga with only 1 AI, the reading was correct, that's why I thought if I can run 2 FPGA simultaneously then the problem would be solved, but it seems like I can only run one FPGA at a time. By the way, I was using Labview Evaluation Kit (sbRIO-9636).

2. I configured my AI to DIFF as well, as for the RSE the noise is about 0.3, then for the DIFF, the noise is about 0.002 only (the case where only 1AI in the fpga), that's why I choose to configure it to DIFF, plus my sensor is a floating source.