Does Visa have any buffer/memory or similar?

[RavensFan]

Bytes at port is a property node.  You could use a >0 primitive to get a boolean value to wire to an indicator.

[CarlosSp]

I can use "Bytes at port" only with a VISA application

[Ray.R]

Are you referring to somthing completely different / other than the VISA buffer / read issue discussed in this thread?

I'm confused..

EDIT:  Using > 0  is a cleaner approach.  Thanks Ravens

Message Edited by Ray.R on 03-19-2009 12:52 PM

[CarlosSp]

Yes Ray, now I'm talking about something completely different. Sorry if I didn't open a new post, but I thought it would be a silly question and easy to answer. Now I'm not talking about VISA any more, only it's a wire were data goes trough in the middle of my application.

[Ray.R]

Can you show a bit of the code or explain where it originates from, what it passes through, and where it ends up (lighting a LED?)?

We'll need to reset our brain cells on this one 😉

[CarlosSp]

jajajajaja ok ok. Sorry if I don't put the code, but it's a project that other people is involved in and it's not only my decision.

Data comes from a frame of a GPS, where I cut it and have the position, zone etc etc and show it in an indicator. I want to put a LED that turns on when an indicator is refreshed so I have a wire that comes from a string cutting command and goes to the indicator, well in some cases there are more things but that are the basics, so I can't get a boolean from a wire where there is a number or a string.

[RavensFan]

---

CarlosSp wrote:
Yes Ray, now I'm talking about something completely different. Sorry if I didn't open a new post, but I thought it would be a silly question and easy to answer. Now I'm not talking about VISA any more, only it's a wire were data goes trough in the middle of my application.

---

A new post may not be necessary.  But letting us know you changed topics is.

---

CarlosSp wrote:
I want to put a LED that turns on when an indicator is refreshed so I have a wire that comes from a string cutting command and goes to the indicator, well in some cases there are more things but that are the basics, so I can't get a boolean from a wire where there is a number or a string.

---

When do you want the LED to turn off?  After a fixed period of time?  Just blink on and off each time it gets a new value (on one time, off the next)?

I am going to assume the 2nd.

With this code, the LED will go from on to off or off to on any time a value gets passed to the numeric indicator, even if it is the same value.

Message Edited by Ravens Fan on 03-19-2009 02:59 PM

[Ray.R]

I think he wants it to turn On when the value changes...  Or at least that was my perception.

In that case, slightly modify the while loop to include a shift register which will contain the last value of the data (from GPS?).  Compare that previous value with the new / present value using "Not-Equal-To" and that will give you a boolean TRUE is the value changed.  If it's the same, then it will be FALSE, thus turning the LED off.

Is this what you wanted?

BTW:  the shift register is obtained by right-clicking on the edge of the while loop and selecting "add shift register".  Whatever value goes in at the right will be the next value coming from the left.

R

[RavensFan]

---

Ray.R wrote:

I think he wants it to turn On when the value changes...  Or at least that was my perception.

In that case, slightly modify the while loop to include a shift register which will contain the last value of the data (from GPS?).  Compare that previous value with the new / present value using "Not-Equal-To" and that will give you a boolean TRUE is the value changed.  If it's the same, then it will be FALSE, thus turning the LED off.

Is this what you wanted?

BTW:  the shift register is obtained by right-clicking on the edge of the while loop and selecting "add shift register".  Whatever value goes in at the right will be the next value coming from the left.

R

---

That could be.  It would make more sense from a programming point of view.  .I was basing my code on the interpretation of  "I want to put a LED that turns on when an indicator is refreshed".    It all depends on what he really means by that statement. 

But it all depends on how fast this code is running and how often that value changes.  If the code runs very fast, my interperation would be a very rapid blinking LED.  In your interpration.  Fast code with rapid changes of value would be an LED that appears to be almost always on.  Fast code with slow value changes would be an LED that just barely blips if it can be seen at all for the rare instance a value change does occur.

Perhaps he could put into words exactly what he wants this LED to mean and do from a real world point of view.

[Ray.R]

agreed 🙂

it will either appear to be always ON or always OFF..  LOL!

Maybe I should write a Nugget of the importance of "Requirements Specs", even for posting questions on the forum...  (remember that ver very long thread last year?)