I have configured a set of tasks in NI MAX for analog and digital input and outputs (AI, AO, DI, DO). AO, DI, and DO all have channels assigned from within NI MAX. AI, however, has no channels assigned. At the moment, I am not using it, but will in the future. For that reason, I still have the DAQmx read function in place for AI, but since there are no channels assigned, according to the tooltip on the DAQmx read function, it should read no data. However, when run, I get 4 ghost values on AI. All other tasks read their corresponding channels properly. Because of this ghost data, the data logs are a bit confusing since there should be nothing there.
I have attached pictures of the task in NI MAX as well as the VI reading the ghost data itself, though it about as basic as it gets. The input (DAQ Tasks) that corresponds to "Analog In" is the AI task. So given that it has no channels, it should read no data.
The odd thing is, if I remove one of two analog input modules from the cRIO (the one with 4 inputs it must be reading from), it no longer reads those values. But why does it read them in the first place? I don't specify any channels.