Schmitt Trigger

[ThomasD]

Hello,

I like to do a Schmitt Trigger function with the VI in the attachment. I use LV 6.0.

Current function:

x <= 991             LED on

x >= 1008           LED on

991 < x < 1008   LED off

Desired function:

change over from x = 1007 to x >= 1008 LED on and by decreasing values LED on till X >= 1006

                        <___________________       LED on

                        |              |

                        |              | 

____________|______>|                               LED off

1000            1006       1008

Any ideas?

Regards

ThomasD

[Odd_Modem]

If LED=OFF and value = 1007 then LED = OFF
If LED=ON and value = 1007 then LED = ON
If value => 1008 then LED=ON
if value =< 1006 then LED = off

[ThomasD]

Is there some text missing in your post? If not, yes, this is what I want to do but how to realize?

[Odd_Modem]

I don't have LabVIEW 6 installed but here is a picture.

[ThomasD]

Hi Odd,

thanks for your answer, that´s what I want.

I have modivied the VI, so there are now hysteresis for an upper and a lower value.

Regards ThomasD

[altenbach]

---

@ThomasD wrote:

                        <___________________       LED on

                        |              |

                        |              | 

_____________|_______>|                              LED off

1000            1006       1008

---

One simple translation into LabVIEW code is shown in the attached image.

Message Edited by altenbach on 12-20-2005 01:14 AM

[ThomasD]

Nice and simple!

[frayre]

Thanks a lot for yor design i think you help a lot of people

[Mazin]

Hi,

I would appreciate it if you can help here. I want to use Schmitt Trigger in my design. I am using a USB-1208FS DAQ to convert the analog signal from ultrasonic sensor to digital (0-5V). I used two digital output ports in the DAQ, each port work individually (0-5V). I calibrate the sensor to get the distance. I used the calibration equation in labview to get the distance. The threshold I am looking for is the heights of plants (0-6 inch is weeds), (6-12 inch is plants). So, less than 6 inches is weeds, and greater than 6 inches is plants. How can I use the Schmitt Trigger to control the digital output ports? Attached is the VI I am working on. Thanks

[johnsold]

Mazin,

It probably would have been better to start a new thread than to tag on to one that is 8 years old.

Have you tried the code that altenbach suggested?  It is not completely clear what you want the Schmitt trigger to do. How much hysteresis do you want?

Lynn