How can I create a digital output to 7 channels?

[saber]

I need to create a digital output for 7 channels and this have to change in a variable interval from 20ms to a 1sec, attach is a .xls file with my profile

[Bill B]

Hello,

Thank you for contacting National Instruments!

I was not sure if you already had hardware for this application, but the solution that I recommend involves using one of our NI 6533 boards.

Here is a link to the device: http://sine.ni.com/apps/we/nioc.vp?cid=13508〈=US

This device has 32 digital lines that can be used as input or outputs. This board will allow you to load your array of data from your output profiles and accurately output the data while using the hardware to time the change in states of each digital line.

The benefit to using this card is that it will update much more consistently than one of our static digital boards. Our static digital boards rely upon the software to time the line changes. Although, this approach may wor
k, it will not be as consistent or accurate as a hardware timed solution such as the 6533. Also, if you wanted to add more outputs, you could easily do so by just adding more data to your output profile. You could have up to 32 total digital output lines with this board.

Let me know if you need more information of if you would prefer an alternative solution.

Regards,
Bill B.
Applications Engineer
National Instruments

[saber]

I have a 6533 board, And yes it be nice to have more info of hardware timing for this application and how to create the digital profile on lines os the same port and on different ports.

Thanks

[Bill B]

Hello saber,

Are you going to be programming your 6533 in LabVIEW? Let me know what language you plan on using and then I will point you to some examples.

Regards,
Bill B.

[saber]

Yes, in labview 6.1.

Thank you.

Abraham S.

[Bill B]

Saber,

I have attached an example program for doing a Buffered Pattern Output. You can modify this example and load your profiles data for each line. You have 8-bits to work with per port. So for 7 lines, you would need to load the unsigned 8-bit integers into the port data written array. You can also view this data as binary if you wish. The update rate will control how fast each element of your port data array is written. Currently, the data to be written is generated in software. If possible, you may want to ave the software read your excel file and create the data array for you.

Let me know if this example helps.

Regards,
Bill B.

[saber]

Now I'm generating the pattern from my file but it's updating every pattern ona constant rate.
Who can I change the update rate reading the time in (ms) from a array?

[Bill B]

Saber,

The 6533 has an update clock that will run at a constant rate. Once you start outputting data, you will not be able to adjust the rate of the update clock. What you will need to do, is modify your data so that the actual frequencies of your signals change at the rate that you wish. You will not be able to adjust individual frequencies for each line while you are outputting data. You must modify your data so that when you begin to output the data at a consistent rate that you get the desired frequency for each line.

Regards,
Bill