What does it stand for in a practical sense? See a pic attached. - Page 1
Forum section: electronics / testgear

author: CiscERsang
author_rank: Regular Contributor
timestamp: October 24, 2019, 01:45:23 pm
content: Hello everyone,I mean f = 2,75....KHZ that is located at the top.Of course I know that is a frequency. Is it a frequency of what? How many times per second the trigger has been triggered. Or?

author: StillTrying
author_rank: Super Contributor
timestamp: October 24, 2019, 02:07:23 pm
content: "How many times per second the trigger has been triggered."Yes, when the trigger is cleanly triggering once per cycle of the input signal it's the same as the input signal's frequency.

author: CiscERsang
author_rank: Regular Contributor
timestamp: October 24, 2019, 02:29:57 pm
content: Quote from: StillTrying on October 24, 2019, 02:07:23 pmand in a practical sense?

author: StillTrying
author_rank: Super Contributor
timestamp: October 24, 2019, 02:53:14 pm
content: "and in a practical sense?"A useful 2 or 3 digit frequency counter ? I use it all the time to check the triggering's working and the frequency is what I expect.

author: CiscERsang
author_rank: Regular Contributor
timestamp: October 24, 2019, 02:56:33 pm
content: Quote from: StillTrying on October 24, 2019, 02:53:14 pma frequency of what? For example, I see a single pulse on the screen and triggering on its e.g. pos. edge. Also I see at the top f=3KHZ. Does it mean that this pulse appears with a frequency = 3KHZ?

author: AVGresponding
author_rank: Super Contributor
timestamp: October 24, 2019, 03:05:20 pm
content: If it's a single pulse, the scope is extrapolating a nominal frequency from the pulse's on time(probably)

author: StillTrying
author_rank: Super Contributor
timestamp: October 24, 2019, 03:09:52 pm
content: Also I see at the top f=3KHZ. Does it mean that this pulse appears with a frequency = 3KHZ?Yes.If you have only one pulse displayed on screen or lots of them it'll still show the frequency of the pulses.

author: CiscERsang
author_rank: Regular Contributor
timestamp: October 24, 2019, 03:12:04 pm
content: Quote from: StillTrying on October 24, 2019, 03:09:52 pmif it's so, I find it as a quite useful stuff!Thank you!

author: CiscERsang
author_rank: Regular Contributor
timestamp: December 15, 2019, 07:21:46 am
content: Hello again,here is a frame which is triggered with f=19.2kHz, if trust the picture. Is it plausible value? Does it mean that the frame appears (is being sent) ~19000 per second?What do you think about?

author: Rerouter
author_rank: Super Contributor
timestamp: December 15, 2019, 07:29:13 am
content: I would use cursors to confirm here, it is more that your trigger level is crossed at that rate each second.

author: StillTrying
author_rank: Super Contributor
timestamp: December 15, 2019, 01:03:54 pm
content: "here is a frame which is triggered with f=19.2kHz, if trust the picture. Is it plausible value?"It's the total number of rising edges per second, so it's the number of bits per second rather than frames.The Y amplitude is a bit low, because...The "Trig Level" is actually 2 levels with about 0.2 Div between them, the waveform's rising edge has to cross both of them, which maybe why you have to have the trigger near the top edge of the waveform.