Release date for PXIe Modules

[AustinMcElroy]

I had a couple of questions about PXIe:

1) I see that a controller and chassis have been released, when will Digitizers and DAQ cards be released?
2) It is my understanding that a PXI card that is plugged into the PXIe chassis will work, but NOT receive the 1GB/s bandwidth, is this true?  In other words, PXI cards do not get the bandwidth upgrade, just PXIe cards.
3) I saw in the PXIe tutorial that PXI cards can be sent in and the J2 pin port will be replaced to make it into a PXIe hybrid card.  Would this card gain the benefit of the 1GB/s bus speed?

Thank you in advance,
Austin McElroy

[Collin M]

I'll answer your last two questions:

>>It is my understanding that a PXI card that is plugged into the PXIe chassis will work, but NOT receive the 1GB/s bandwidth, is this true?  In other words, PXI cards do not get the bandwidth upgrade, just PXIe cards.

There are different types of slots in PXI Express chassis. A PXI card can be plugged into a hybrid slot or a PXI slot. A PXI slot can only accept a PXI card. A hybrid slot can accept a PXI card or a PXI Express card. In order to insert a PXI card into a hybrid slot, it must have the J2 connector replaced as you stated. Some PXI cards do not have a J2 connector and these need no modification.

PXI and PXI Express cards use different types of busses to connect to the system. PXI cards use only the PXI (PCI) bus while PXI Express cards use a PCI Express link. Electrically, the two busses are not compatible or interchangeable. Hybrid slots support both busses, but a card only uses one or the other. The bandwidth available to a PXI card does not increase if it is plugged into a hybrid slot as the PXI card will only use the PXI bus, not the PXI Express bus.


>>I saw in the PXIe tutorial that PXI cards can be sent in and the J2 pin port will be replaced to make it into a PXIe hybrid card.  Would this card gain the benefit of the 1GB/s bus speed?

No, this card still connects using the PXI (PCI) bus. The PXI Express bus in the hybrid slot will not be connected to the PXI card. The PXI card will not be able to access the bandwidth provided by the PXI Express bus.

This is a subtle point, but a PXI card that has been modified to work in a PXI Express hybrid slot is known as a "hybrid slot-compatible PXI module". A "PXIe hybrid card" seems to imply a card that uses both the PXI Express and PXI busses. I doubt such a card would ever be designed.

[AustinMcElroy]

Collin M:
Thank you very much. Perhaps it was mentioned in the PXIe FAQ or Tutorial, but I couldn't find a clear explanation though.  Yours is perfect!

If anyone would like to answer the 1st question, that would be greatly appreciated.  I can't find anything about PXIe modules.  I am looking for a PXIe digitizer that can do 110MS/s and stream the data real-time to the HD.  Using existing PXI technology with the smallest bit resolution (8-bit), I am looking at 110MB/s that needs to be streamed, which is pushing the theoretical PXI limit of 132MB/s.  I have seen elsewhere in the forums a PXI card that allows for 200MB/s transfer rates to a back-up HD, but was hoping to just use PXIe modules for simplicity sake.

[Adam_U]

Back on the topic of PXI Express, some people out there may find the web tutorial linked here useful. It describes the different connectors, bus technologies, etc. that are used in the PXI Express specification.

-Adam