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Thread: E4991A


Permlink Replies: 2 - Pages: 1 - Last Post: Apr 6, 2011 7:01 PM Last Post By: chard
chard

Posts: 35
Registered: 07/24/07
E4991A
Posted: Mar 16, 2011 7:22 PM
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Hello,

I'm GPIB programming the E4991A impedance analyzer. I want to read the trace data from the analyzer to my computer. I'm having problems synchronizing the analyzer sweep with my program. I first make a call to the analyzer to trigger a new sweep via the GPIB. This works. Then, I make the call to read the trace data. In my case, that call is "CALC 4 :DATA? FDATA". Once this call is made, the data is read from the analyzer. However, the triggered sweep is not necessarily completed. I want to add to the program something to assure that the sweep is complete before retrieving the data. In the past with VNA's, I would use an OPC or OPC? command to assure a sweep/command is complete before retrieving the data. I need a command to interrogate that the sweep is complete.

Right now, I've resorted to reading the sweep time and just sleeping for that period before retrieving the data. I don't like having to use that crutch.


Thanks
lhornburg

Posts: 478
Registered: 01/15/10
Re: E4991A
Posted: Mar 29, 2011 10:48 AM   in response to: chard in response to: chard
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There is no difficulty in the method of detecting the end of sweep measurement before reading measurement data by using CALC{1-5}: DATA?FDATA command with a GPIB system.
You can use OPC? command to verify the completion of a sweep measurement. In order to utilize the OPC? command effectively, be sure to initialize the operation status register of the E4991A before executing the OPC? Command. A sample program for detecting a measurement end using SRQ is provided in Chapter 5 (on page 114 and 115) of the E4991A Programming Manual:
http://cp.literature.agilent.com/litweb/pdf/E4991-90052.pdf
I would quote the program lines 300 to 350 or the sweep subprogram portion from the sample program provided in the manual (as shown below.)

Image

Thank you very much and best regards,
chard

Posts: 35
Registered: 07/24/07
Re: E4991A
Posted: Apr 6, 2011 7:01 PM   in response to: chard in response to: chard
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Thanks for taking the time for this detailed response.

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