08-11-2023 09:29 PM
Currently, I want to purchase PXIe-6386 and connect to BNC-2110, to synchronize the analog inputs, I need to configure external clock. However, when I see the spec of BNC-2110, I could not find whether the connector for AI0 to AI7 has the same wire length. The wire length is important for signal synchronization. Do anyone know if the wire length in BNC-2110 is the same or what is the length difference? Thank you.
08-11-2023 09:41 PM
In short, it should not impact your measurements a lot given your sampling rates.
Let us do some napkin calculations, approx. 1ns delay per 6 inches of wire. Taking a worst-case trace length difference of 12 inches, you would see the signals between two channels differ by 2ns. Now, since your sampling rate is 14MS/s, the sampling time is going to be the best case 71ns, so, a 2ns difference would not result in a sync difference as 2ns << 71ns.
08-15-2023 03:12 AM
Let me clearify my perspective,
I want to use PXIe-6386 to acquire two-photon fluorescent signal from photomultiplier (PMT). Since I use 8 MHz femtosecond laser to stimulate the two-photon fluorescense, the fluorescent signal lifetime is only few nanoseconds.Therefore, I use laser electirc signal to be the external sample clock, and 2ns do influence the signal intensity.
Peter
08-15-2023 06:02 AM
Specified bandwidth is 6 MHz... ??
However, you go down the rabbit hole, so I see no onther way that you need measure the timedelays of your system to characterize your interchannel delays (for a given setup).
How good do you thing is the internal synchronity of the ADCs?
Matching them with the help of some individual cable length shouldn't be a hard thing.
I don't know the internals of the DAQ you use, if you have a good RF generator in sync with your DAQ, measurring the delay using subsampling technics makes sub ns resolutions easy possible.