using PXI and PXIe at "the same time"

[Garcas]

I have an application where I need to have a high speed digitizer (PXIe5122) acquirirng continuosly at 20 MS/s while being able to process the incoming data as fast as I can. Of course I am not expecting to reach "real time" processing speed, but as the acquisition only lasts for 60s for the moment this is not a problem (the processed data could be available a "little bit later")

I am planning to use a PXIe-1065 (or 1062Q) chasis with a PXIe-8106 controller. I was considering using the system controller only to retrieve the acquired data from the PXIe-5122 (though PXIe) and stream it to disk. I would place another processing card in a PXI slot and use it to process the data. The controller would have to send the data to the processing card trough PXI

Having read the NI PXIe-8106 documentation there's something I still don't get: would I be able to take advantage from both PXI and PXIe buses at the same time, or are both buses multiplexed at the chipset I/O controler?

I am trying to avoid placing the second processing card in a PXIe slot because I would have to program the PXIe bridge to transfer the data. We have allready developed applications with several procesing cards in a PXI chasis and we had had a lot problems programming the bridges, so now that it's working in PXI we would prefer not having to do all this work again

thanks. kind regards

guillermo

ps. by the way, "offline" (or post) processing is not an option as we need to have some infomartion before the experiment ends

[JaimeC]

Hi,

This is a good option this chassi has 3 slots for PXIe (slots 3, 4, 5) with a direct connection 4x PXIe each one to the controller slot (slot 1). Also has 1 PXI common bus for the other slots (slots 2,3,5,6,7 and 8 being slots 3 & 5 hybrid so can be used as PXI or PXIe with support for both type of  cards).

Then u can stablish 3 4xPXIe and 1 PXI links at the same time to the controller.

I have seen a video in the NI Days at Austin (USA) where a 1042Q chassis and a 8106 controller are acquiring and plotting one RF application, one high speed digityzer and one video signal with an overall transfer rate over 850 Mbps.

Then this controller supports all connections at same time, so you will have all this bandwith for your use.

Is a great improvement in measurement systems allowing new applications that require a high bandwith be controlled within a PXI system.

Hope you go on with this configuration, I 'm shure you will enjoy it.

[Tim Fountain]

Hello,

You will be able to use both PCI/PXI and PCIe/PXIe "at the same time". Another aspect that needs more consideration is the stream to disk requirement. Even 1 channel at 20Ms/s is 40MB/S of data, 2.4GB per minute. The 2.5" HDD's used in the embedded controllers are not really going to be able to reliably sustain 40MB/s or above. You will need to look at dedicated disk streaming technolgoies such as the 1U 4 drive RAID array and 3U 12 drive RAID array NI announced at NIWeek for PXIe. Also at these data rates you need to consider exactly what kind of processing you will be able to do.

Finally I am interested to learn more about what kind of in-line processing you have done to date, would it be possible for you to PM me with more details?

Thanks

- Tim Fountain, Product Strategy

[Garcas]

Hi Tim

Thanks for your help, and sorry for the delay. I have been doing some preliminary tests and finally I have decided to test the system using a PXI 6115 in a standard PXI chasis. If the architecture gives good results we will consider moving to PXI Express

I don't know how to PM you, but if you want you can send me an email to "garcas at sec dot upm dot es" (sorry for the spelling) and I will send you more info

Best regards

guillermo