I have a cDAQ-9172 chassis with 2 modules installed in slots 1 and 2. Slot 1 contains a 9234 and slot 2 contains a 9205. The 9205 module is only reading 1 channel. The fellows running the experiment are complaining that there seems to be a delay between channel readings. They have a timing signal connected to channel 9234 AI3 and a pressure signal connected to the 9205 AI0 and the graph in the software interface is showing a shift that is not present when the two signals are connected to an oscilloscope. The manual for the cDAQ-9172 states a 10 uS delay to allow for settling time for each channel of a scanned module. Aside from that, I can find no reference to any other delays in the system. As the 9205, which is a scanned module, only has one channel, there should be no 10 uS settling time. The 9234 module has 4 simultaneous input channels thus there should be no delay between them. I have connected the same square wave signal to each channel and indeed all of the simultaneous channels on the 9234 are perfectly lined up and show no delay, however, they do lag the lone 9205 signal. Can you please point me to documentation that confirms the inter-module delay amount and also confirms that this is consistent regardles of sample rate. If we can quantify it we can adjust for it in post processing. We just need to know what that delay is and that smapling rate has no bearing. Alternatively, if you have a solution for this problem, or can explain what I am doing wrong, that would be even better!
