Tektronix TDS2014B. The scope free runs just fine under it's own control but under SignalExpress control it repeatedly triggers creating a recording that is discontinuous bursts of data.

[Nathan-P]

Thanks, I've contacted R&D to find out if this is expected behavior or where the appropriate configuration would be, this isn't as intuitive as I would have thought.  I'll let you know as soon as I hear back.

[Nathan-P]

So I heard back from R&D, and we have a few more questions about the behavior of your scope:

1. What signal are you trying to measure on the scope?  From the screenshots it just looks like noise, so we want to verify that the signal itself is a continous signal.

2. If you were to create a simulated IVI Scope, does it's acquired signal appear the same?

3. How long after you start acquiring data do you begin to have the gaps appear in the signal?  Do they happen right away?  

4. When you run your SignalExpress code, do you use the "Run Once" button or the "Run Continuously" button?  The Run Cont. should allow you to collect continuous data.

Lastly, could you attach your SignalExpress program/project file(s) soon?  We'd like to see if we can reproduce the behavior.

[DrElectrode]

So I heard back from R&D, and we have a few more questions about the behavior of your scope:

1. What signal are you trying to measure on the scope?  From the screenshots it just looks like noise,

so we want to verify that the signal itself is a continous signal.

In this case, we are monitoring a 60Hz sine wave. This project monitors voltage and current during circuit breaker testing.

2. If you were to create a simulated IVI Scope, does it's acquired signal appear the same?

I’m out of time today. I will report on this item tomorrow.

3. How long after you start acquiring data do you begin to have the gaps appear in the signal?  Do they

happen right away? 

Right away.

4. When you run your SignalExpress code, do you use the "Run Once" button or the "Run Continuously"

button?  The Run Cont. should allow you to collect continuous data.

When initially selecting the Record button, when the dialog box closes, it goes directly into continuous mode. Subsequent runs are initiated by clicking the Run button. I haven't written any code for this application. I am relying on native SignalExpress.  

Lastly, could you attach your SignalExpress program/project file(s) soon?  We'd like to see if we can

reproduce the behavior.

See attachments.

[DrElectrode]

Sorry, here are all the files zipped.

[Nathan-P]

I've got a scope to try your code on and I'll do that today, also the following article will help with setting up IVI drivers in SignalExpress:

http://www.ni.com/white-paper/4594/en

[DrElectrode]

In answer to a previous question:

2. If you were to create a simulated IVI Scope, does it's acquired signal appear the same?

Interestingly, there is a definite demarcation at the horizontal scan of 10mS. From 11mS (11mS is sort of cheating since this isn't available on the physical scope) and up (tested up to 100mS), there is a good, continuous trace. At 10mS it begins recording a discontinuous trace. Please see the attached project for examples.

[Jacob_R]

Hello,

I set up a TDS 2014B by my desk, installed Signal Express Tektronix edition 2.5.1 on my Windows 7 32 bit machine, plugged in the device via USB and was able to measure a clean sine wave from a signal generator. The signal was roughly 1000Hz with an amplitude of 1. To properly see a clean data signal on the data view, it was important to configure the y axis and configure the horizontal scale.

Your data looked like mine did when I was measuring noise. Make sure that you have connected all the wires properly, including ground, and start with only measuring one signal on one channel. I used Ch1.

Here are screenshots of my configuration:

1- Max configuration

2- Signal Express step

3- The Step setup tabs

4- The Data view

[DrElectrode]

Red flag.

In MAX under My System, I do not have a heading "Devices and Interfaces", only Software and IVI Drivers. In SignalExpress, I can select Add Step>Tektronix>Aquire Signals>Tek TDS1000/2000. Hmmm...

[Jacob_R]

It could be that Devices and Interfaces only shows up if you have our DAQmx driver installed. Do you have other NI software installed? Does the device show up in MAX at all?

[DrElectrode]

No other NI software installed. See the screen capture below for the MAX config tree: