Hi! I've just started using a cDAQ 9188 with an NI 9208 (as discussed in my own latest query), so hopefully I can help.
Firstly, could you upload a snapshot of the block diagram you're using?
Secondly, are you certain that the NI 9208 is running in high speed mode? If you're building the task programattically (rather than creating it in MAX), there's a specific property node you have to call in order to change it out of its default high resolution mode, and I, at least, found it a bit tricky to find.
Remember that the speed of the NI 9208 is measured in samples per second, which are distributed over all of the input channels. If you're reading 16 input channels on one NI 9208, then even in high speed mode, it takes 2 ms per sample, which means 32 ms to collect data from all of the channels, so you'd only get ~ 32 Hz on each channel. In high resolution mode, you'd get about 3 Hz.
I think the problem might be the buffer size, however. Why is it set to 1?
My advice would be to increase the sampling rate that you set in the DAQ assistant, and either increase the buffer size or let it use the default size (which is based on the sampling rate, I believe).
Also, if your loop is iterating at 10 Hz, then try saving a sequential trace of your DAQ Read outputs at each iteration (into a shift register, for example). If your data is only actually changing once per second, then are you getting ten identical DAQ Read outputs in a row? Or are you getting a set of data, and then nine lots of "no data available"? The latter would indicate something to do with your buffer size and sampling method, whereas the former would indicate that the NI 9208 just isn't sampling as quickly as you'd like it to.
