Limit Switch/USB 6501

[Jose M.]

Hello everyone,

I have a limit switch connected to the USB 6501.  I want to use that limit switch to trigger an evert.  That event is an HTTP get.  I have the HTTP get set up in a true false loop that I can toogle between T/F using a "virtual" switch.  I need to replace that virtual switch with the limit switch.  Can anyone recommend anything?  Thanks

[Abhinav T]

Jose,

The 6501 does not have any triggering built into its hardware. If your limit switch gives out a TTL signal for when it is triggered you can read it on one of the lines on your 6501 and check for a trigger in software (compare with a previous read to look for an edge).

Is this what you are looking for? If you provide a little more information on your application I maybe able suggest something a little better than a software trigger.

Thanks

[BrandonAGr]

I'm attempting to do something similar, I recently got a 6501 and am developing an application in C, I want to have external buttons that I can then trigger a software event with when they are pressed. Since the 6501 does not have digital input triggering(which was my first guess on making this work, since I don't want to ever miss a button press no matter how quickly the button is pressed and released) I will need another method.

Here is my current idea for implementing a way to capture button presses reliably, I could create a simple flip flop circuit so that when you press a single button a digital signal will be held high until it is reset by an outside signal, this way when you press a button and release it this line would be held high, then when the software checked the line, it would read that it had been pressed, then the software would use a digital output line to reset the flip flop and make the button signal low.

Has anyone created something like this before, does it sound like it would work?

[PBear]

Hi Brandon,

I think that sounds like an excellent solution given your device. Many times some external circuitry can go along way in complimenting your DAQ devices.