measuring voltage parameters in TDS7404

[Mathan]

Dear all,

Am using TDS7404 oscilloscope and via another PC through ethernet am controlling the scope. I have installed the tktds7k drivers. As i posted in the other very old thread (that's why it didn't got more attention it seems!), now am able to measure some of the basic parameters like amplitude, frequency, Duty cycle, rise time, fall time etc. The problem of getting 99.00 e36 is solved by adding required delay between visa write and read.

Now for measuring high transition and low transition voltage and for high steady state and low steady state voltages, manually we have to adjust (move) the cursors in the scope and there is no option to measure the values directly like other parameters i mentioned in the first paragraph. Can somebody tell me how to measure automatically the transition and steady state voltages without adjusting the controls in the oscilloscope (i hope with the help of the drivers it is possible). Please guide me how to achieve this.

Thanks,

Mathan

[Christian Mergl]

Seems that no one in this forum ever tried this before....I'm one of them.

I would contact Tektronix support, the should know best how to use there instruments, also with LabVIEW instrument drivers.

Christian

[Mathan]

Thanks a lot Christian for atleast responding to this post.

Am taking a deep look at the drivers to get something positive. Will update here soon.

Thanks,

Mathan

[Dennis_Knutson]

I think you might be looking in the wrong place. You should really start by studying the manual. If there are built-in measurement functions and/or cursor move functions, once you know that, you can simply search the driver for the command.

You might also want to do the measurement in the pc instead of the scope. This would require you to transfer the waveform and then use the LabVIEW analysis functions.

[Mathan]

Vow finally i got the expected response from our favorite Sir Dennis.... Thanks a lot. Yes i do have to study the manual for the commands as you said. Will update once i get something fruitful.....

Thanks,

Mathan

[Mathan]

---

Dennis Knutson wrote:

I think you might be looking in the wrong place. You should really start by studying the manual. If there are built-in measurement functions and/or cursor move functions, once you know that, you can simply search the driver for the command.

You might also want to do the measurement in the pc instead of the scope. This would require you to transfer the waveform and then use the LabVIEW analysis functions.

---

These are really golden words. I did looked at the manual and yes there are built in measurement functions and cursor move functions and in the drivers everything is very easily traceable. Thanks a lot Dennis.

Yes am taking measurement in a separate PC and not in scope since it is having win98 OS and am using LabVIEW 8.6. So remote control of scope via TCPIP. I didn't came across analysis functions. I didn't got the idea of why it is needed and how it is used.

Mathan

[Mathan · Accepted solution]

For future use:

1) Initialize.vi

1) Cursor state.vi

2) Cursor mode.vi

3) Cursor type.vi

4) Cursor source.vi

1) Set Trigger Type.vi

2) Set trigger transition parameters.vi

1) Get cursor parameters.vi

1) Close.vi

[Vaibhav_Vashisht]

Ah, thanks for the list 🙂

[Mathan]

I need to measure the voltage of CLK (red dot in the picture) at 1 msec prior to VCC rise to 0.4V as shown in the figure. I got the waveform from the scope and there are lot of cursor functions (horizontal and vertical) available in the drivers. Any method how to measure this?

Message Edited by Mathan on 08-18-2009 05:11 AM

[Shreyas]

Hi,

     try using Pre-trigger data in DAQ mx. Hope that solves!