Is my DSO glitchy, or it's me? (Delayed single-sweep)

[Ariel Cornejo]

Hello...

I haven't been long around DSOs, so I don't know if I'm getting
something all wrong (reads: please bear with me It's an HP54615B.

I'm trying to trigger on the first rising edge of a signal on CH1
and some 12ms later capture a detailed data frame on CH2. I set

Source=CH1, Mode=Single, Coupling=DC, Level=2.0V, Hor.Mode=Delayed,

and place the delayed-sweep window around the place where the
data frame starts. Then I hit ERASE-RUN, and the main trace shows
both signals as expected (CH1 on the trigger mark, CH2 transitions
inside the window). Then it may:

a) Keep blinking the (1^) sign, as if waiting for a second trigger,
no trace on 2nd window
b) Stop blinking, no trace on 2nd window
c) Time-out (?) some 5 secs later and correctly trace the delayed-sweep
as indicated.


The manual reads:
"Main and delayed sweeps are obtained in alternate acquistions.
Single sweep in delayed mode acquires on trigger for main and
one trigger for delayed." (I believe there is a typo and it
should read "ONE trigger for main and one trigger for delayed").

Still, this doesn't explain the (apparently) erratic behavior.
żWho's wrong, the scope or me?

Thanks for your ideas,

- ariel

 

[Mark (UK)]

Hi!

I would find it odd that it can only capture the traces alternately?
Doesn't the chop function work in storage mode? It surely should be able
to capture both traces simultaneously, that's part of the point of
storage isn't it?

I'm not familiar with that particular model though....still using a Tek
7633 analog storage beast here

Yours, Mark.

Ariel Cornejo wrote:

Hello...

I haven't been long around DSOs, so I don't know if I'm getting
something all wrong (reads: please bear with me It's an HP54615B.

I'm trying to trigger on the first rising edge of a signal on CH1
and some 12ms later capture a detailed data frame on CH2. I set

Source=CH1, Mode=Single, Coupling=DC, Level=2.0V, Hor.Mode=Delayed,

and place the delayed-sweep window around the place where the
data frame starts. Then I hit ERASE-RUN, and the main trace shows
both signals as expected (CH1 on the trigger mark, CH2 transitions
inside the window). Then it may:

a) Keep blinking the (1^) sign, as if waiting for a second trigger,
no trace on 2nd window
b) Stop blinking, no trace on 2nd window
c) Time-out (?) some 5 secs later and correctly trace the delayed-sweep
as indicated.


The manual reads:
"Main and delayed sweeps are obtained in alternate acquistions.
Single sweep in delayed mode acquires on trigger for main and
one trigger for delayed." (I believe there is a typo and it
should read "ONE trigger for main and one trigger for delayed").

Still, this doesn't explain the (apparently) erratic behavior.
żWho's wrong, the scope or me?

Thanks for your ideas,

- ariel

 

[Ariel Cornejo]

"Mark (UK)" <jumbos.bazzar@btopenworld.com> wrote in message news:<cebsm9$hd7$2@titan.btinternet.com>...

Hi!

I would find it odd that it can only capture the traces alternately?
Doesn't the chop function work in storage mode? It surely should be able
to capture both traces simultaneously, that's part of the point of
storage isn't it?
No, I didn't mean chop mode - it does capture the traces simultaenously.

From what I understand, main/delayed sweeps are done on alternate triggers
(trigger->main sweep, trigger->delayed sweep, trigger...).

I'm not familiar with that particular model though....still using a Tek
7633 analog storage beast here
I've had the pleasure to use Tek7000s. Too bad the ppl in charge didn't

give them proper maintenance and they decided to phase them out and
bring in a lot of cheap 20-MHz GoldStars (eww). I loved that
mix-and-match modularity (hmm... 4 channels or dual timebases?).

Yours, Mark.

greetings,

- ariel