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How to program a Pulse generator

  1. Sep 1, 2016 #1
    Hi there! is anyone here working with a pulse generator? I have Agilent 8114A Pulse generator i want to vary the frequency automatically like 1.1Hz to 10.1Hz with 1-2 secs delay. This pulse generator have a HP-IB bus at the back that can connect in a PC. Base on the Manual it can program using SCPI command but i don't know to to do it please someone help me thanks!

    https://www.google.com/url?sa=t&rct...Ai1KTkW158XC57IHuXtdXQ&bvm=bv.131669213,d.cGc
     
    Last edited by a moderator: Sep 1, 2016
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  3. Sep 1, 2016 #2

    Nidum

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    SCPI is short for Standard Commands For Programmable Instruments . There is a lot of good information easily found on the internet .

    What is your actual problem ?
     
  4. Sep 1, 2016 #3
    My problem is, how to vary the frequency automatically.
     
  5. Sep 1, 2016 #4

    Baluncore

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    I looked in the manual at the frequency, period setting functions and the index. It appears that it does not support a frequency sweep or chirp function.

    If you need the high voltage and currents you could use an external trigger to produce pulses. That would require an external sweep generator, or programming a microcontroller such as an Adafruit Trinket (US$5) for the triggering task. We can quickly write the code for a trinket if you specify the frequency sweep parameters.
     
  6. Sep 1, 2016 #5
    The parameter that i used are: Amplitude voltage = 5V, delay =0.0ns, Resistance = 50 ohms, cycle =50% and frequency = 1 to 100 with an 0.1 interval and have 2 seconds delay. Thank you very much for your help!
     
  7. Sep 1, 2016 #6
    May you suggest an external trigger (brand and model, the cheapest one) that works in my pulse generator?
     
  8. Sep 2, 2016 #7

    Baluncore

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    Agilent 8114A manual, page 3-18 describes “External Width Mode”. EXT-IN becomes the input to the pulse generator. The pulse generator voltage is programmed as usual, but it gets all time control from the external signal input edges. See index ... EXT INPUT, 2-3, 3-7. EXT INPUT Threshold, 4-90. EXT WIDTH, 4-86. EXT WIDTH mode, 4-86. EXT WIDTH Mode, 3-18
    Your timing parameters do not seem to make sense. What does the two second delay refer to ?
    Can you please draw a waveform and show the timing at the start pulse and end pulse of the sweep. Drag and drop it onto your reply window. Once we know the timing required we can decide on the best trigger unit to control the pulse generator.
     
  9. Sep 2, 2016 #8

    f95toli

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    Do you have access to Labview? If not. do you know any normal programming language (e.g. Python)?
    The programming should be fairly simple and you can send SCPI command from most programming languages. However, you will of course need a PC with GPIB card so that you can actually connect to the generator.
     
  10. Sep 2, 2016 #9
    So First, your saying using "External Width Mode" we can program the frequency, but we need an external sweep generator? (can you provide brand and model?).
    Second, if we set the frequency in 2Hz, based on my experiment the generated voltage is not stable (range from 20mV-10mV), but as your increased to 100Hz it generates a more stable voltage (12-11mV). So that i think, we need a delay to established more stable voltage (or at 2 seconds we can average all the generated voltage at each frequency) so the graph will be the "average generated voltage within 2 second" vs. frequency.
     
  11. Sep 2, 2016 #10

    Baluncore

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    You do not appear to know what you are doing. You wrote “Amplitude voltage = 5V”, now you write “(range from 20mV-10mV)”. If you cannot answer questions or produce an accurate waveform diagram then I cannot advise you on a sweep generator that will be capable of doing the job.
    What amplitude do you really require ?
    What are you using the swept frequency pulses for ?
     
  12. Sep 2, 2016 #11
    I'm sorry i didn't tell the whole story. So first i have experiment in piezoelectric material. I will apply AC voltage (using pulse generator) and then i will measure the output voltage using oscilloscope. From that i need to determine the resonant frequency, by sweeping the frequency. When i hit the resonant frequency, the generated voltage is so high that when you plotted it, you will have a spike or peak. The 20mV-10mV that i mentioned is the output voltage not the input from the pulse generator. So the Parameter that i need are: Amplitude voltage = 5V, delay =0.0ns, Resistance = 50 ohms, cycle =50% and frequency = 1 to 100 with an 0.1 interval and have 2 seconds delay.
     
  13. Sep 2, 2016 #12

    Baluncore

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    It must be a long bar of piezo material to resonate between 1 and 100 Hz. If you hit a piezo structure with a hammer, or a single pulse, it will ring at it's resonant frequency.

    Maybe throw out the Agilent PG and use something like; FY2212S DDS Function Sweep Frequency Signal Generator. The square wave output could be used to drive the Agilent PG. Expect to pay about US$100. eBay search; FY2200S sweep
    The instruction manual is here; http://www.eevblog.com/forum/testge...43;PHPSESSID=8a0fe36d745f5936fe0b0fb719a73ea3
     
  14. Sep 3, 2016 #13
    Actually i have a bimorph piezoelectric material (piezo-film deposited in Stainless steel substrate), and based on simulation the resonant frequency is around 20Hz.
     
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