How to achieve the fatest Digital IO write speed?

[Yfayne]

How fast can I write to a digital IO port?How to achieve the fatest write speed? For test purpose, after config port, using DIO Port write.vi in a whileLoop by 6024E board,repeatly write1-2(01 and 10bin), i can only get a speed about 10kHz,i.e. every 106 us write a byte, can that be faster? how? software solution and hardware solution? Thanks!

[JoshuaP]

Hey Yfayne,

It is very hard to say how fast you can write the digital lines on an E-Series device, because it is completely software and computer dependent. The exact same DAQ device with the exact same code will execute completely different on a 233MHz machine when compared to a 2.4GHz machine, because it depends on how fast the computer can execute the loop. If your program slows down to perform another task like opening another program or surfing the web it will slow the rate the computer can execute the loop and mess up the timing.

In addition, the digital lines on the E-Series use the DAQ-STC chip that was never designed for high speed. If you need a high speed hardware time device I would suggest using the PCI-6533 or PCI-6534. The devices were desig
ned for high speed digital applications and can easily exceed the 10 kHz rate consistently.

Here are a few links that you will find useful.

http://zone.ni.com/devzone/conceptd.nsf/webmain/467ed254f3a30b1286256a6f00720951
http://sine.ni.com/apps/we/nioc.vp?cid=1104〈=US

I hope this helps out.

Joshua P.
Application Engineering
National Instruments