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Time Acquisition Vee 6.2,VNA 8510C and Agilent 82357A

Question asked by Giorgio on Apr 26, 2010
Latest reply on May 6, 2010 by UndeadBob

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Dear All

i use Agilent VEE 6.2, VNA 8510C and the Agilent 82357A USB/GPIB inteface for windows.
My problem is the time acquisition of the data.
I make a program where i acquire the S21 parameter with the VNA set in Continuos Wave and i put it in an array (1 Dimension).
In particular i acquire the S21 parameter in a cycle (Until Break) and to take it very fast i acquire the marker displaying only the S21 parameter on VNA 8510C.
The time acquisition of the single marker is very slow for my application.

Using a timer in the cycle the time to read the data is about 1,5 sec and it is not regular (it changes from 1,4 to 1,8 sec).

So what can i do to acquire the data in a faster way?

Why the time is not regular?

Thank you in advance for your helpfulness

Giorgio De Angelis

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UndeadBob Apr 27, 2010 9:01 AM
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"
Thank you for your response but using int 32 i reduce the the accuracy of the S21 parameter.

Moreover in this day i try to use Matlab and Labview and with this two software the speed to acquire the data is faster with respect to VEE and this is very strange because in the case of VEE i use the instrument's driver while in the case of matlab and labview no.

So it's not a problem of the obsolete instruments and interface but probably of my old version of VEE.

I don't know if the new version have the same problem!!!!!!

Any additional suggestion???
"

I found your program in this thread... Two major issues come to mind:

1) You say your trying to integrate with MatLab and Labview to "acquire the data is faster". Every time you jump from one language to another, your going to slow down. It's like using a battery to charge a motor to generate electricity in which case you get less that 10% efficiency.

2) After looking over your program, I see about 40 inefficiencies within 50 lines... If you can access your drivers without VEE, I would recommend it. Otherwise, try to get some VEE training. Try to get away from the legacy component drivers and use non-legacy gpib. I'm not sure if the 8510C supports SCPI. If it does, seriously consider Direct I/O instead of component driver commands.

In general, just try to reduce all the clutter after the "Until Break" (which in your case could be replaced by a "For Count" because that's all you're doing).
You should be able to reduce it to: "For Count" > "MARKER_VALUE_1" > "Collector" > "Logging AlphaNumberic"
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Giorgio Apr 28, 2010 2:20 PM
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Dear UndeadBob and Dear All

Thanks a lot for your interest and your suggetions

1) You say your trying to integrate with MatLab and Labview to "acquire the data is faster". Every time you jump from one language to another, your going to slow down. It's like using a battery to charge a motor to generate electricity in which case you get less that 10% efficiency.

I didn't integrate VEE with Matlab and Labview. I use directly Labview. With this software the time to acquire a data is about 101 msec Vs 1,5 sec of VEE.
I don't use Matlab but speaking with other people they say me that they have not this problem.
In any case i don't want to use Labview but i want to use VEE because this is the software of my instrumentations and i hope in the future to upgrade VEE's version .

2) After looking over your program, I see about 40 inefficiencies within 50 lines...

What are the problems??? Can you tell me???

Try to get away from the legacy component drivers and use non-legacy gpib.

sorry but i don't understand

In general, just try to reduce all the clutter after the "Until Break" (which in your case could be replaced by a "For Count" because that's all you're doing).

i need until break for a future upgrade of the program

If it does, seriously consider Direct I/O instead of component driver commands.

I'm starting to use Direct I/O. I'm not an expert of this component in fact i used it only to interface a multimeter and a Power Supply.
So now i have a problem:
from the Agilent Technologies 8510C Network Analyzer System Operating and Programming Manual to acquire a marker (in particular MARK 1) the command is

MARK1 9 GHz; OUTPMARK;

so this command puts the marker 1 at 9 GHz and it gives me back the value of it.
In the Direct I/O i write "MARK1 9 GHz" and the mark1 is really set at 9 GHz then i read OUTPMARKER (without ") but the VNA gives me the message (error 811 on VEE) that i don't specify the output variable (on my VNA video is only visualized the S11 parameter (Single Display) and there is only the marker 1). Moreover i subsequently tried to read OUTPDATA (so i want to read directly the S11 parameter) and the same message appear on my VNA (always in single display mode).

Where is the problem? Can you help me?

Thanks a lot in advance
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UndeadBob May 6, 2010 6:34 AM
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I've never written a program for a network analyzer, but I'll try to help.

"
What are the problems?
"

"
i need until break for a future upgrade of the program
"

Not sure what your future goals are, so I'll leave that one alone. The inefficiencies are probably a minor problem which may save you 10% speed, but I provided an example of a clean-up. As your program is 1000% slower than LabView, the problem is probably in the transaction.
VNACW2_6May10.vee
I understand the need for the until break, but I tried to clean it up without changing your I/O. I don't have your network analyzer, so I can't debug, but it should work.

With regards to your 811 error, it sounds like your I/O module isn't configured right. When you drag & drop from your Instrument Manager, you get a gray box to which you add transactions. You first transaction should be something like "MARK1 9GHz". Ok, i just downloaded this manual... chapter 13 (p.306)

Wow... this is BASIC. Ok, I see that
OUTPUT 716;"S11;MARK1 9 GHz;"
might work, but i never did find what the "716" is for. Seems to be interchangeable with "@Nwa". Ok nevermind...
ASSIGN @Nwa TO 716 !This sets up the I/O path for the network analyzer

That's crazy. Do you know where a VEE programming guide for the 8510C would be? Looks like you'll have to stick with your component driver commands. If the program above doesn't speed it up much, then you're just SOL. I hope someone else from the community has some input on this simple problem.

Ok, so you do need legacy GPIB.
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Time Acquisition Vee 6.2,VNA 8510C and Agilent 82357A

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