How to program a Pulse generator

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Discussion Overview

The discussion revolves around programming an Agilent 8114A Pulse Generator to automatically vary its frequency from 1.1Hz to 10.1Hz with a delay of 1-2 seconds. Participants explore the use of SCPI commands for programming and discuss potential external solutions for achieving frequency sweeps.

Discussion Character

  • Technical explanation
  • Exploratory
  • Debate/contested

Main Points Raised

  • One participant seeks assistance in programming the pulse generator to vary frequency automatically.
  • Another participant explains SCPI as a command set for programmable instruments and asks for clarification on the specific problem.
  • Some participants note that the manual indicates the generator does not support frequency sweep or chirp functions.
  • Suggestions include using an external trigger or a microcontroller like an Adafruit Trinket to achieve the desired frequency variation.
  • There are discussions about the parameters used for the pulse generator, including amplitude, delay, resistance, cycle, and frequency range.
  • One participant questions the timing parameters provided and requests a waveform diagram to better understand the timing of the pulses.
  • Another participant mentions the need for a stable voltage output at different frequencies and suggests averaging the generated voltage over a delay period.
  • Concerns are raised about the accuracy of the parameters shared by one participant, particularly regarding the input and output voltage levels.
  • One participant describes their experimental setup involving piezoelectric materials and the goal of determining resonant frequency through frequency sweeping.

Areas of Agreement / Disagreement

Participants express differing views on the capabilities of the pulse generator and the methods to achieve the desired frequency variation. There is no consensus on the best approach, and several competing ideas are presented.

Contextual Notes

Some participants note limitations in the pulse generator's functions as described in the manual, and there are unresolved questions regarding the specific parameters and their implications for the experiments being conducted.

ralden
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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
 
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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 ?
 
My problem is, how to vary the frequency automatically.
 
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.
 
Baluncore said:
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.

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!
 
ralden said:
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!
Baluncore said:
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.

May you suggest an external trigger (brand and model, the cheapest one) that works in my pulse generator?
 
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
ralden said:
... and frequency = 1 to 100 with an 0.1 interval and have 2 seconds delay.
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.
 
ralden said:
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!

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.
 
Baluncore said:
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.

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.
 
  • #10
ralden said:
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!
ralden said:
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.
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 ?
 
  • #11
Baluncore said:
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 ?

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.
 
  • #12
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
 
  • #13
Baluncore said:
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

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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