How to measure Ch1 - Ch2 in Scope

[kazu]

Hi, I need help to use the script in "WaveForms".

I don't know much about Javascript, but I need to measure the time from the change point on channel 1 to the change point on channel 2.
Please let me know if anyone has a reference script.

[attila]

Hi @kazu

You could use Phase measurement or FFT phase for sine/periodic signals.
The following script looks for value on channel 2 which at least as high as the value in the middle of channel 1

var rg2 = Scope.Channel2.data
var c = rg2.length
var c2 = c/2
var v1 = Scope.Channel1.data[c2]
print("Voltage:", v1)
for(var i = c2; i < c; i++){
    if(rg2[i]<v1) continue
    print("Time:",(i-c2)/Scope.Time.Rate.value)
    break
}

[kazu]

On 9/25/2020 at 6:43 PM, attila said:

Hi @kazu

You could use Phase measurement or FFT phase for sine/periodic signals.
The following script looks for value on channel 2 which at least as high as the value in the middle of channel 1

var rg2 = Scope.Channel2.data
var c = rg2.length
var c2 = c/2
var v1 = Scope.Channel1.data[c2]
print("Voltage:", v1)
for(var i = c2; i < c; i++){
    if(rg2[i]<v1) continue
    print("Time:",(i-c2)/Scope.Time.Rate.value)
    break
}

Thank you for the sample script.
Sorry for the lack of explanation.
The waveform I'm assuming will look like an attachment.
With my knowledge of Java script, I can't get the Ch1-Ch2 time from the sample you taught me.
Please let me know if you have a good sample.

Thank you Regards.

[attila]

Hi @kazu

function dt(){
    var rg1 = Scope.Channel1.visibledata
    var rg2 = Scope.Channel2.visibledata
    var c = rg1.length
    var i1 = 0
    for(var i = 0; i < c; i++){
        if(i1==0){ // Ch1 below 1.5V
            if(rg1[i]<1.5) i1 = i
        }else if(rg2[i]>1.5){ // Ch2 above 1.5V
            return (i-i1)/Scope.Time.Rate.value
        }
    }
    return -1
}

const ctest = 300
var nssum = 0, nsmin = 1e9, nsmax = 0
Scope.run()
for(var i = 0; i < ctest && Scope.wait(); i++) {
    var ns = dt()*1e9
    if(ns<0) throw "Error"
    nssum += ns
    nsmin = min(nsmin, ns)
    nsmax = max(nsmax, ns)
}
Scope.stop()
print("Average:", nssum/ctest, "ns")
print("Min:", nsmin, "ns")
print("Max:", nsmax, "ns")