Xiang Li

Please see attached pic, chan 1.&#160;<br> Is there a way for me to get how much time the clk spends in tri-state (marked red in pic)?&#160;<br> For instance, I want to sum up all the time it spends from say 1.4 to 1.6 V and divide it by the total duration which in this case should be &gt; 50%.&#160;

The badge was yellow so chan1.&#160;<br> I have set the abs levels and it definitely helped. I now see expected freq stats.&#160;<br> One more question about the low level.&#160;<br> See attached pic. you can see the min of the trace is 233 mV which is quite a bit higher than the &quot;low&quot; that i have set (-1 mV) so how come it's still able to give me accurate frequency stats?&#160;<br> What I'm expecting is that the freq badge should give me empty value until I raise the &quot;low&quot; of the abs ref level to around 250 mV (higher than 233 mV so it triggers).&#160;<br> Doesn't the waveform have to cross &quot;low&quot; AND &quot;mid&quot; AND &quot;high&quot; to be counted as one cycle?&#160;<br> I'm using AND in the sense of logic &quot;and&quot; meaning that all 3 have to be satisfied at the same time.&#160;

Please see attached pic &quot;multi cycle&quot;. The pulses bounce around a bit but the periods center around 500 us, which should translate to 2 kHz avg but the badge gives me 20+MHz average frequency.&#160;<br> I have also included a pic zooming in on one pulse.&#160;<br> How do I configure the scope to give me more accurate stats?&#160;

please see attached pic (chan1) for a series of (filtered) clk signals.&#160;<br> I want to be able to use scpi to tell the scope to give me the positive pulse width stats of:<br> 1. using custom reference levels of 90% to 90% (marked H in the pic) and&#160;<br> 2. using custom reference levels of 10% to 10% (marked L in the pic)&#160;<br> <br> what i'm trying to do is to see if the clk is being tri-stated in the samples by comparing the max of&#160;10% to 10% and&#160;90% to 90%.&#160;<br> you can see from the pic the the one being tri-stated will have bigger&#160;positive pulse width only from 10% to 10% not 90% to 90%

1. How do I use SCPI to add a label to channels? say &quot;PWM&quot; to chan1 and &quot;SW&quot; to ch2?&#160;<br> 2. How do I use SCPI to limit a chan (say ch2) to BW of say 20 MHz?

my question is are these below cmds correct?&#160;<br> if not, what should they be?&#160;<br> <br> <br> MEASUrement:MEAS1:SOUrce1 CH4D_0<br> MEASUrement:MEAS1:SOUrce2 CH4D_1

Looks like I do have SVID sub but I'm not sure of the difference between the installed and upgrade one.&#160;<br> Please see pic attached.

Where can I purchase the license of protocol analysis for my MSO44 4-BW-500?&#160;<br> How do I know if it already has it?

I tried adding CLS in the init but I'm still having issues. 

def __init__(self, addr):
    self.addr = addr
    self.rm = pyvisa.ResourceManager()        # rm.list_resources()
    self.inst = self.rm.open_resource(self.addr)
    self.write("*CLS")
    print(self.query("*IDN?"))
    self.write("*CLS")

Do you see anything wrong with the below function? (I keep getting timeout errors at random lines in the below funciton. )
If not, can you please share a scope shot retrieving routine that's robust? 

def get_screenshot(self):
    now = str(datetime.datetime.now()).replace(":", "-")
    # print(now)
    self.write(f'SAVE:IMAGe \"C:/{now}.png\"')
    self.query("*OPC?")
    self.write(f'FILESystem:READFile \"C:/{now}.png\"')
    imgData = self.inst.read_raw(1920 * 1080)
    cwd = os.getcwd()
    full_path = cwd + "\\scope screenshots"

    Path(full_path).mkdir(exist_ok=True)

    filepath = full_path + "\\" + now + ".jpg"
    file = open(filepath, "wb")
    file.write(imgData)
    file.close()
    self.write(f'FILESystem:DELEte \"C:/{now}.png\"')
    return filepath

How is the accuracy of digital channels compared to analog channels. I know it throws out quite a bit of information. It's more like a threshold lo/hi. Do you think using this method is detailed enough if I'm interested in phase delay down to 0.1 degree?