Trig on chA, acquire chA & chB, get rid of data from chB
t=i+1 --> Trig on chB, acquire chA & chB, get rid of data from chA
etc...
Scheme 2: f = 250MS/s , only one channel on at one time.
t=i --> Turn off B, turn on A, Trig on chA, acquire chA
t=i+1 --> Turn off A,turn on B, Trig on chB, acquire chA & chB
etc...
Scheme 2 produces a higher freq data which is better. However, turning on and off the channels produces some overhead, but I am mostly concerned about the robustness of the clicking switch/relay operating every time this is done. I am talking about 1000 times a day... What would you recommend?
Note that I initially was considering using logical triggering, but I had issues with it (separate post in software/LabVIEW forum), plus it does not help on the sampling rate front. I also considered using ETS, but according to the specs it only works with Block Mode, not Rapid Block Mode...
Thx.
Laurent
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I am using a Pico 4227 for an application that requires the device to be operating hours at a time. The general procedure being implemented is a Rapid Block Mode acquisition at 250MS/s (1 ch) or 125MS/s ( 2 ch) and filling up the buffer with a few thousands points at most, repeatedly ~ 500 times every cycle. The operation takes in the order of a few seconds before it is resumed again. Now working with 2 channels, and having meaningful data coming in alternatively one channel at a time ( chA, chB, chA, chB etc...) I am working on a trigger scheme that for each cycle also alternates which channel is used as trigger input. It looks like this:
Scheme 1: f = 250MS/s, effectively producing f = 125MS/s since 2 channels are turned on, both channels always ON.
t=i --> Trig on chA, acquire chA & chB, get rid of data from chB
t=i+1 --> Trig on chB, acquire chA & chB, get rid of data from chA
etc...
Scheme 2: f = 250MS/s , only one channel on at one time.
t=i --> Turn off B, turn on A, Trig on chA, acquire chA
t=i+1 --> Turn off A,turn on B, Trig on chB, acquire chA & chB
etc...
Scheme 2 produces a higher freq data which is better. However, turning on and off the channels produces some overhead, but I am mostly concerned about the robustness of the clicking switch/relay operating every time this is done. I am talking about 1000 times a day... What would you recommend?
Note that I initially was considering using logical triggering, but I had issues with it (separate post in software/LabVIEW forum), plus it does not help on the sampling rate front. I also considered using ETS, but according to the specs it only works with Block Mode, not Rapid Block Mode...
The decision will really depend on which is more important to you in terms of sample rate or wear/tear of the device. Another solution would be to drive two scopes from your application.
I understand that, but I do not know the specs of the device in question with regards to turning on and off a channel. So this is the part I need your help for. Essentially what is the # cycles the ON OFF relay (if it is a relay) in the 4227 can take? There should be a spec for this.