Slicing a signal while measuring

[User3086107985]

Hello everyone,

We are measurring a charging current. At some point the current drops significantly because the device is full. Afterwards the device will periodically recharge to keep the battery charged.

We need to analyse the charging signal and the keep-charged-signal 

individually and automatically.

We could do this in post by running a flank function and finding points in the signal. However we would prefer to cut the signal during measurement as does not require a script but just the DAC plan.

However I don't know how to slice the measurement data. I tried using two saving blocks that get stopped/started by a signal. However DIAdem does not seem to like that my two blocks are not recording at the same time which is kind of the point.

Is there any way to slice a signal? We do want to keep both measurements obviously and we want to automate everything.

Im glad for every help or Inspiration how to tackle the Problem differently

[markwkiehl]

Are you using the DIAdem DAC panel with a DAQ card attached / installed and the charging current signal going to the DAQ device?

Can you please post a View plot of the signal and annotate it with the the signal characteristics you need to programmatically identify. A sample of the data would be helpful too.

I have a NI DAQ card and some experience with the DIAdem DAC option. I have extensive DIAdem experience otherwise.  Sounds like an interesting project. 

[User3086107985]

Hello and thank you for your Time,     

I have a OPC server running that connects to a power supply that enables me to get the Current / Voltage / Power    

Tha DAC Plan is quite straightforward. The Current is analyzed in 1. If a sudden Drop is detected we send out the Impulse to stop measuring in Save loading(3) and start measuring in saveStandby (4).  The Charging process first needs to be initiated, and the Current drops multiple times during the initiation. That’s why (2) is in Place: The Timer waits for two mitutes before going high. This way the first few current drops are ignored.    

The Peaks can easily be Found in Post processing: A simple event search finds every Drop(Red). You can see the initial Drop (A) we want to ignore using the timer. Instead we want to trigger on Event B   

 once again thank you for your help!

[Walter_Rick · Accepted solution]

Hi User3086107985,

Please have a look at the attached example DAC. Hopfully it is what you are looking for.

Greetings

Walter

[User3086107985]

Hi Walter,

This did not quite do, what I wanted it to do, however your plan helped me understand, how to solve my problem. I just had to change the logic that triggers the slicing.

For everyone looking at this in the future:

Stopping and starting the clock signal (for a few pulses(?)) will "slice" the signal. You will have "Time 1"/"Current 1" and "Time2"/"Current2". You can do this as often as you want.

Pausing the clock signal can be achieved using a trigger that gets started by a signal and stopped by the same signal with a delay.

 All these solutions are present in Walters helpfull Plan. Thank very much for your help Walter!