NI PXI-8360

[S.H.]

Hi to all,

I have some questions using NI PXI-8360 card controlled by laptop with ExpressCard if anyone can help.

The kit that contains NI PXI-8360 & NI PXI-ExpresCard8360  is working fine using the HP laptop but when I use another ExpressCard (generic) by other manufacturer the Laptop does not recognize the PXI system. Is there something in the NI ExpressCard different from other ExpressCards and how to make other cards to work with NI PXI-8360 if any at all.

The second question: the max (?) cable length for the system to work is 7 meters, or can it be longer (8-10 meters)? What makes it not to work if longer cable is used (signal integrity, Bandwidth...).

Any answers will be greatly appreciated.

S.H.

[Ali M]

Hello,

The issue with using longer cables is signal degredation/latency and you risk losing information, or passing incorrect data along the cable. Regarding the generic card,

a few things to take note of is whether you have the proper driver to support the card/if it meets specifications of the Express card. A good place to start would be to look into

the detailed spec sheet your card and perform a comparison, I have included a link below with additional information. 

1. MXI-Express Series User Manual and Specifications: http://digital.ni.com/manuals.nsf/websearch/567F3D6838FF08AA862576A200751AAC

Regards,

Ali M

Applications Engineer

National Instruments

[Robert__R]

S.H.,

The NI PXI-8360 isn't compatible with generic cards because of some electrical differences. 

Longer cables can have problems with clock jitter and signal amplitude.  The extra delay in longer cables becomes problematic because of spread-spectrum clocking used in PCIe systems, and you will start seeing errors from clock jitter or frequency tolerance.  The attenuation of the PCIe signal will make it difficult for the receiver to correctly decode bits, so you can get errors from that.

It's unlikely that the errors will directly result in bad data because of PCIe error checking.  If the link is bad enough that data can't get through in a timely manner then you could get time-outs, which result in bogus data being returned to software.  Otherwise bad packets get retransmitted.

In many cases you will be able to run with longer cables, but it's not guaranteed to work across time, temperature, host systems, and MXI kits.

I hope that helps.

Robert