multiplexing channels after the analog inputs of a DAQ Hardware

[ENST]

Hi,
I need to sample a 5KHz analog signal with 48 channels.
It's needed all these channels simultaneos.
I know there is not a DAQ hardwere at NI beyond 4 simultaneos channels.
How could I or NI solve this problem? Have NI an hardware that could be applied?

[JustinBritten]

Greetings,

You are correct in that there are no simultaneous sampling boards that have more than 4 channels. Performing truely simultaneous sampling will ensure that there is virtually no interchannel delay and that the phase relationship between each signal is retained. If you use a regular Multifunction Input/Output DAQ board and some sort of signal conditioning, like SCXI, to increase your channel count, you will be performing a multiplexed operation. However, in most cases the interchannel delay is on the order of microseconds. If this is still too much for your application then I'm affraid the only answer is to get multiple Simultaneous Sample boards. You would want to trigger each board's acquisition to start at the exact same time. In order to
do this you could either use a PXI system or use PCI and leverage RTSI.

However, even with this suggestion you should keep in mind that most PCs only have 5 PCI slots, which will limit you to 5 * 4 = 20 channels. If you went with a PXI system and used the PXI-1006 chassis, which has 18 slots, then you could fill it with 12 PXI simultaneous sample cards.

PXI
http://sine.ni.com/apps/we/nioc.vp?cid=1525〈=US

NI PXI-1006
http://sine.ni.com/apps/we/nioc.vp?cid=4889〈=US

S Series Multifunction DAQ
http://sine.ni.com/apps/we/nioc.vp?cid=10834〈=US

Regards,
Justin Britten

Applications Engineer
National Instruments

[ENST]

Is there any device in NI that I could multiplexe 12 inputs channels at any input of a NI PCI-6115.
It will not be simultaneo but speed enough.

[JustinBritten]

A good method for increasing channel count is to use an SCXI system and our analog input multiplexer amplifier modules. Unfortunately, the PCI-6115 is not compatible with SCXI signal conditioning.

Does the 61XX Family of Simultaneous Sampling MIO Devices Support Signal Conditioning (SCXI, SC, SCC, SSR, or 5B)?
http://digital.ni.com/public.nsf/websearch/E053CC777C9909E086256977005A413E?OpenDocument

Again, for high channel count, board synchronization, and fast sampling all in one system, you may need to consider PXI.

Regards,
Justin Britten