PCI-DIO-96 Speed vs. Parallel Port

[erand]

Hi !

We are using a Chip that was developed by us and until now we communicated with it through the Parallel Port of the Computer.

Recently we started to use the PCI-DIO-96 Card to control our Chip with Board.

The Problem is that now the communication is 40 times slower than with the Parallel Port.

Can anyone give me some hints or tips to make it faster ?

Thanks

Erand

[Daniel_L]

Hi Erand,

Thank you for contacting National Instruments!  If you are using the PCI DIO 96, this device is software timed, as you can see in the datasheet.  Software timed means that the generation rates are deteremined by the rate at which your software loop executes, which is based off your operating system's onboard clock, which is generally in the kHz frequency range. 

If you refer to that same datasheet, you'll see a nice chart on page 7 that shows the different digital product families (high speed DIO, isolated DIO, and low-cost DIO), and the applications that each can perform.  The PCI DIO 96 (also known as 650x) falls under the low-cost family and you'll see that it does not support hardware timing. 

As for speeding up software-timed loops, the best advice I can offer is to minimize the code within your while loops.  If you have alot of unnecessary code within your while loops (i.e. initialization and cleanup code that can be placed before and after a loop), your loops will run at much slower rates.

I hope this information helps,

Daniel L.
Applications Engineer
National Instruments