Products > Test Equipment
Test Equipment Anonymous (TEA) group therapy thread
bd139:
Yes that is true. Unfortunately to select a trigger you need to understand what the problem is before the event. Intensity grading did result in the capture of this issue for ref. However I had to capture a large chunk of samples for it to have enough resolution to capture the event more than once to establish delta t and be observable at the same time. We’re talking 1 in 800 pulses was 20ns short here. Capture done in single sweep mode and then eyeball trigger :)
tautech:
--- Quote from: bd139 on May 31, 2018, 11:26:32 pm ---Yes that is true. Unfortunately to select a trigger you need to understand what the problem is before the event. Intensity grading did result in the capture of this issue for ref. However I had to capture a large chunk of samples for it to have enough resolution to capture the event more than once to establish delta t and be observable at the same time. We’re talking 1 in 800 pulses was 20ns short here. Capture done in single sweep mode and then eyeball trigger :)
--- End quote ---
Yeah fine until you need to correlate it to a possible cause/source with additional channels running. That's when an advanced trigger is your friend. DSO's shine at this, not so much CRO's.
bd139:
Yep exactly that. Once you’ve worked out when something is happening and what it’s doing when it’s happening you can set up a suitable trigger for it then look around the circuit for why it is happening with other channels. I love the DSOs for this.
In the above situation I knew what was happening due to the suspiciously around 18ms glitch frequency which usually points to WDT. One clrwdt instruction added and sorted thus proving with a red/green test that it was the root cause. Not all things are that simple. Debugging weird shit is the most fun you can have I find, probably why the day job ended up being software.
Incidentally this capability is when tek realised they needed to give up the analogue scopes i reckon. Even a 2467 “bright eye” is quite frankly useless at picking this sort of crap up. It’ll tell you what is happening but you’ll have to use another tool to work out why.
tautech:
And yet in this day and age there are still some that insist your first scope must be a CRO, ::) it was for me and I learnt a ship load but a DSO is a more capable tool.
mnementh:
--- Quote from: bd139 on May 31, 2018, 11:45:40 pm ---Yep exactly that. Once you’ve worked out when something is happening and what it’s doing when it’s happening you can set up a suitable trigger for it then look around the circuit for why it is happening with other channels. I love the DSOs for this.
In the above situation I knew what was happening due to the suspiciously around 18ms glitch frequency which usually points to WDT. One clrwdt instruction added and sorted thus proving with a red/green test that it was the root cause. Not all things are that simple. Debugging weird shit is the most fun you can have I find, probably why the day job ended up being software.
Incidentally this capability is when tek realised they needed to give up the analogue scopes i reckon. Even a 2467 “bright eye” is quite frankly useless at picking this sort of crap up. It’ll tell you what is happening but you’ll have to use another tool to work out why.
--- End quote ---
Yeah, but if YOU had been operating in SE debugging mode instead of EE diag mode, you'd probably have guessed that and tried it without ever needing to drag out the DSO. ;)
That's something younger minds are often better at... shifting gears/changing operating modes. The problem is they usually want to do it when it ISN'T called for. :-DD
mnem
As a matter of fact, I DO know jack shit! Plug shit TOO! :o
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