Can you give me a example?

[6677_3PH240]

Now I want to acquire 16 Anolog inputs at the same time (the frequency of my signals are about 1.5KHZ),and my device are PXI6052E and SCXI1141,can you give me a example to solve my problem?(IN Bridgeview,the example named 'Cont Acq& chart(hw timed).vi) always gives me a 10845Error at AI SignaleScan.

[Geneva L.]

This is usually due to limitations of your computer system, most commonly the result of slow processor speeds (< 200 MHz) in conjunction with boards that have small FIFO buffers. The 6052E has a 512-sample size. Sometimes using a board with a larger FIFO helps, but a better solution is to lower the acquisition rate or move to a faster system. Perhaps you're using MXI-3 connected to a slower desktop processor instead of a fast PXI controller?

Another cause of the -10845 error could be due to an interrupt-driven acquisition. CPU intervention is thus necessary to transfer data from the board FIFO to RAM. This bus limitation can quite seriously affect a continuous background data acquisition (since CPU resources for analysis and display are competing with the reso
urce requirements for moving the data off of the board). Check that you have DMA resources assigned to the 6052E, and you can call the Set DAQ Device Info.vi to set your data transfer mode to DMA, to try that instead.

You can also find this information in the KnowledgeBase. There are a number of entries discussing this error. You can start at the http://www.ni.com/support page and choose KnowledgeBase from the Technical Resources pull-down menu. Then, you can type in keywords, such as "10845" to see those entries.

Geneva L.
Applications Engineer
National Instruments
http://www.ni.com/ask

[beitzer]

I think, NI Service is taking the problem too easy.
I encounter error 10845 in several situations even with fast Processors (PIII 800 MHz / 256 MB RAM) and do not have it with really old ones as PI 166 (data rates of 80.000/s with NI-DAQ 700 writing contiuously to disk usually work).
It seems to depend on details of the hardware which we usually do not really know (especially in Notebooks).

The situation seems better with Win98, and really bad with Win2K. Up to now Notebooks with Win98 usually worked, but recently I got one with PII 350 an W98 which did not beyond data rates of 25.000/s.

Obviously, what happens with error 10845, is described correctly in the knowledge base, but they only say that interrupt response time is a matter of processor speed. Actually it is more a problem of response strategies and priorities.
NI seems not to look for solutions. That would require an adequate redesign of the drivers.

The latest comment I received when I contacted the manufacturer of my PCI-PCMCIA interface for a PCI desktop points at a possibly poor design of the NI driver:

"2.2 Dirty Interrupt Service Routines (ISR's)
============================================
The PSeries hardware relies on interrupts that are
level sensitive and can be shared. This means that
the PC-Card's ISR should be written correctly for
this environment. For most efficient operation, the
ISR should fully handle the IRQ in processor
"Ring 0" (DIRQL), by immediately removing the source
of the interrupt. In most cases this is true, and is
recommended by Microsoft as the way to handle
hardware interrupts. Some poorly written PC-Card
drivers do not handle the interrupt in this way which
is ok for ISA based edge triggered interrupts, but
cause problems in the PCI environment.

The PSeries driver contains special detection logic for
badly behaved ISR's that ensures the IRQ is handled
safely (without crashing the PC), but slowly (at approx
25% of possible performance).
If the PC-Card appears to be operating in this way,
access to the card will be sluggish and the ISR could
receive multiple unexpected interrupts. For improved
performance, you should contact your PC-Card vendor
for an updated driver that correctly handles the IRQ
according to Microsoft recommendations for
interrupt service routines.

The following cards have been detected with
this problem, if you are using one of these cards
you should contact the manufacturer of your card for
an updated driver:
* PROXIM RangeLAN2 wireless LAN card.
* WEB Gear Aviator 2.4 wireless LAN card.
* NoWiresNeeded 11MBPS wireless LAN card.
* Breezecom PRO.11 SA-PCR wireless LAN card.
"