Hi Dan,
Page 20 of the NI 9205 manual covers settling time and accuracy performance of the module. The short answer is that at maximum speed, the multiplexer can switch 250,000 times a second, for a scan interval of 4 microseconds.
In CompactDAQ, the default rate for this multiplexer is set as follows (from page 25 of the cDAQ-9172 manual😞
The driver chooses the fastest conversion rate possible based on the speed of the A/D converter for each module and adds 10 μs of padding between each channel to allow for adequate settling time. This scheme enables the channels to approximate simultaneous sampling. If the AI Sample Clock rate is too fast to allow for 10 μs of padding, NI-DAQmx selects a conversion rate that spaces the AI Convert Clock pulses evenly throughout the sample. NI-DAQmx uses the same amount of padding for all the modules in the task. To explicitly specify the conversion rate, use the ActiveDevs and AI Convert Clock Rate properties using the DAQmx Timing property node or functions.
Regards,
Kyle
