Number of bursts with picoscope 5242D

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fastlite-nicolas
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Joined: Tue Nov 30, 2021 4:13 pm

Number of bursts with picoscope 5242D

Post by fastlite-nicolas »

Hi,
I am using a 5242D to drive a galvanometer from Python 3.6.8.
The idea is to trigger the galvanometer (from the oscilloscope) and have the galvanometer oscillate for exactly one period.

The picoscope performs exactly as expected but for the number of periods: with shots=1 and sweeps=0, I get 2 periods instead of 1.

What is strange is that I cannot reproduce this behavior from the PicoScope 6 software. It seems that this happens only with the SDK (I am using the latest version). I tried with 3 different 5242D and they all behave the same. I tried shots=0 and sweeps=0, but I get a continuous waveform (as expected from the doc). With shots=2 I get 2 periods, with shot=3 I get 3 periods etc. This bug seems only related to shots=1. No error message from the SDK.

Here is the full set of inputs I am feeding to ps5000aSetSigGenBuiltInV2() :
- offset_voltage_ = ctypes.c_int32(0) #no offset
- pk_to_pk = ctypes.c_uint32(1000000) #in µV, 1V amplitude
- wave_type = ctypes.c_int32(2) #enum=PS5000AWaveType["PS5000A_TRIANGLE"] -> on purpose
- start_frequency = ctypes.c_double(gen.frequency) #frequency=startFrequency=stopFrequency (no sweep)
- stop_frequency = ctypes.c_double(gen.frequency) #frequency=startFrequency=stopFrequency (no sweep)
- increment = ctypes.c_double(0.) #no sweep
- dwell_time = ctypes.c_double(0.) #no sweep
- sweep_type = 0 #enum = PS5000A_UP (not relevant)
- operation = 0 #enum = PS5000A_ES_OFF, normal signal operation
- shots = ctypes.c_uint32(1) #single period
- sweeps = ctypes.c_uint32(0) #no sweep
- trigger_type = ctypes.c_int32(0) #rising edge
- trigger_source = ctypes.c_int32(1) # triggered by scope
- ext_threshold = ctypes.c_int16(1000) #not relevant

Has anybody witnessed this behavior ? or found a workaround ? it is a reported bug ?

Best regards to all readers,
Nicolas

bennog
Advanced User
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Joined: Mon Nov 26, 2012 9:16 am
Location: Netherlands

Re: Number of bursts with picoscope 5242D

Post by bennog »

If you have more scopes then you can use 1 with Picosocpe software to see what is coming out of the scope you use with the SDK.

Benno

fastlite-nicolas
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Posts: 0
Joined: Tue Nov 30, 2021 4:13 pm

Re: Number of bursts with picoscope 5242D

Post by fastlite-nicolas »

I did: two periods !

Nicolas

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