Please, read and Question 1 and 2, and answer Question 3 for me.
I have a DAQCard6062E.
The maximum single-channel scan rate is 500KS/s.
Question 1: Can "The DAQCard-6062E scan 2 channels at the maximum single-channel scan rate of 500KS/s" ? Question 2: Can "The DAQCard-6062E scan 10 channels at the maximum single-channel scan rate of 500KS/s" ?
Answer 1: No, "The DAQCard-6062E can scan 2 channels at a maximum scan rate of 250KS/s, scan rates set greater than 250KS/s give an error" Answer 2: No, "The DAQCard-6062E can scan 10 channels at a maximum scan rate of 50KS/s, scan rates set greater than 50KS/s give an error""
Question 3 (True or False)
"The DAQCard-6062E can scan multiple channels at the same maximum rate as their single-channel rate."
I'd like to clarify what that statement means in all E-Series User Manuals. The DAQCard-6062E can sample at 500 kS/s. If you are only sampling one channel, you can "Scan" that channel at 500 kS/s. If you are sampling 2 channels, you are still sampling (converting the ADC) at 500 kHz. However, your overall "Scan" rate is now 250 kScans/s.
The concept that we are tying to convey by this statement is that the sample clock (interchannel delay) does not need to decrease when you are sampling multiple channels as opposed to just one channel.
The rest of this section goes on to talk about times when you would want to consider increasing the interchannel delay to account for source impedances and gain settings.
There's a Board Reference Clock (20MHz on an E-Series), a configurable Scan Clock, and a configurable Sample Clock.
The sample clock can never exceed 500kS/s on a 6062E - consequentially the scan clock can never possibly exceed ( 500kS/s / Channels_being_scanned ) in any configuration.
The "channel clock" would be the sample clock, and it is very different than the scan clock or reference clock.
If you're messing with RTSI: ND_IN_CONVERT pulses each time an ADC can be performed (sample clock) ND_IN_SCAN_START pulses each time a new channel scan starts (scan clock) - and ND_BOARD_CLOCK pulses every 50ns (20MHz) (reference clock)
All of the E-Series cards have a certain bandwidth that they can perform ADC at. The available bandwidth is split between every channel acquiring data.
Question 1 & 2 are the same question. If by "their single-channel rate" you mean 500kS/s, then question 3 is the same as 1 & 2 as well. And the answer is no, of course not. And it makes the most sense that way.
If you buy a T1 and have two people use it, would you expect to get 3Mbps instead of 1.54?
The unasked question is, Can scan one channel at the boards maximum rate? I think it�s true for all E-series card, but it is not true for all NI-DAQ cards. You may or may not be able to scan one channel at 500kS/s, but the aggregate bandwidth used can never exceed 500kS/s with a 6062E. i.e. Y ou may also be limited by a maximum single channel rate (on some cards) of 100kS/s.