DAQmx "wait for next sample clock" never shows "is Late" !

[hookso]

1) my wait is 3 sec

2) when the wait is enabled , the sampling indeed occur at lower rate.

3) when hitting stop, i see no error messages

[JÞB]

OK I'll jump in.

You never set the

Number Of Warmup Iterations Property

http://zone.ni.com/reference/en-XX/help/370469AB-01/daqmxprop/attr22ed/

So it remains at the default 100.  You can't get "is late"=True until the 101st sample.  Period!  (Am I really the only one who ever read the manual on that?)

[hookso]

Tried that allready.

I pass the 101 iterration in  5 seconds if i set the rate to 20 hz.

it doesn't solve the problem.

try it yourself !

[JÞB]

@hookso wrote:

Tried that allready.

I pass the 101 iterration in  5 seconds if i set the rate to 20 hz.

it doesn't solve the problem.

try it yourself !

---

Not the 101st iteration(Sample clock).  The 101st acquired sample.  The first 100 samples cannot be late.  you need 5 minutes to acquire 100 samples.  

Try reading the help file

And don't forget to read the caveats like: What certain types of applications NI recommends the use of that function in.  Unless you have one of these- and I doubt you do- You are missapplying the function anyhow!

[ToeCutter]

At 20 sample/s it's only 5s for 100 samples or am I missing something? I can't see anything wrong with the code- it's pretty much identical to the code in the white paper.

Is the problem sorted or still an issue?

[JÞB]

@TC,

you missed the 3 second delay-  don't sweat it too much!  but, there is a HUGE difference between sample clocks and samples acquired  I really do recommend reading the help file  it is fairly pointed on what the function does and when it is potentially useful....

Beyond those limited use cases...... it really depends on what the hardware supports if the function COULD return "Is Late?" = True.   I jumped in "Splashing!" on the thread because it went down the wrong road.  Someone BLUE Should have beaten me to the punch and asked about the hardware attached.  Yet, the OP was so offended by expected bahavior and ....

For what it is worth- I learn a LOT from my mistakes too... Many of those mistakes are availablefor public viewing on these forums.

[ToeCutter]

Thanks Jeff- this one is a bit of a mare as I can't run it!

[hookso]

Jeff
The 3 sec delay happens only once and not cyclic.
It happens only in the iteration when i click on delay button.
So when i set the rate to 20, it aquires 100 samples in 5 sec.

[ToeCutter]

Do you ever crack this one, hookso? I'm interested in the answer if so.

[hookso]

It started to work all of a sudden.
I dont know what the reason for this, sorry.