Scope "trace" vs. "channel" question

[JosephKK]

Bob Engelhardt wrote:

Can a scope display more "traces" than "channels"? My very basic
understanding is that a "channel" is what has a physical input connector
and a "trace" is what appears on the screen. My confusion is about "4
trace, 2 channel" scopes. To me this implies some kind of special probe
that takes 2 signals and time shares (?) them into a single signal for a
channel's input. Is this right, or does the scope itself somehow have
the ability to accept 4 signals?

Thanks,
Bob

Most of what i have seen like that is when each input can be displayed
as two traces at different timebase speeds. In some ways this is
similar and better that standard dual time base scopes.

 

[Bob Engelhardt]

Can a scope display more "traces" than "channels"? My very basic
understanding is that a "channel" is what has a physical input connector
and a "trace" is what appears on the screen. My confusion is about "4
trace, 2 channel" scopes. To me this implies some kind of special probe
that takes 2 signals and time shares (?) them into a single signal for a
channel's input. Is this right, or does the scope itself somehow have
the ability to accept 4 signals?

Thanks,
Bob

 

[Rich Webb]

On Wed, 13 Feb 2008 09:38:27 -0500, Bob Engelhardt
<bobengelhardt@comcast.net> wrote:

Can a scope display more "traces" than "channels"? My very basic
understanding is that a "channel" is what has a physical input connector
and a "trace" is what appears on the screen. My confusion is about "4
trace, 2 channel" scopes. To me this implies some kind of special probe
that takes 2 signals and time shares (?) them into a single signal for a
channel's input. Is this right, or does the scope itself somehow have
the ability to accept 4 signals?

Could be another case of marketing gone wild.

Trace #3 could be what's variously called "math" or A+/-B. Some scopes
can continue to display the source channels (A and B) as well as the
sum or difference (or other functions) trace.

Trace #4 might be a saved, or reference, waveform. Might also be the
external trigger channel that's sometimes available as a separate
display trace.

Only the datasheet knows for sure.

--
Rich Webb Norfolk, VA

 

[Jim Yanik]

Bob Engelhardt <bobengelhardt@comcast.net> wrote in
news:FsWdnfEHFbFDnS7anZ2dnUVZ_ommnZ2d@comcast.com:

Can a scope display more "traces" than "channels"? My very basic
understanding is that a "channel" is what has a physical input connector
and a "trace" is what appears on the screen. My confusion is about "4
trace, 2 channel" scopes. To me this implies some kind of special probe
that takes 2 signals and time shares (?) them into a single signal for a
channel's input. Is this right, or does the scope itself somehow have
the ability to accept 4 signals?

Thanks,
Bob

there's the trigger signal(ext?) and a delayed sweep that can be the 3rd
and 4th traces on the display.

Or,Ch1 and Ch2,and delayed Ch1 and Ch2.

--
Jim Yanik
jyanik
at
kua.net

 

[Jamie]

Bob Engelhardt wrote:

Can a scope display more "traces" than "channels"? My very basic
understanding is that a "channel" is what has a physical input connector
and a "trace" is what appears on the screen. My confusion is about "4
trace, 2 channel" scopes. To me this implies some kind of special probe
that takes 2 signals and time shares (?) them into a single signal for a
channel's input. Is this right, or does the scope itself somehow have
the ability to accept 4 signals?

Thanks,
Bob
Scopes of that nature have been around for a bit how ever, what

you're looking at is most likely math functions that can be
performed on the CH1 and CH2 inputs to be shown in other traces.
Also, in delay scan functions. it makes it nice to be able to
see the main input and move the cursor where you would like and then
see an expected view of a window portion of that on the next line down.

do that with both inputs sampling a signal and then perform some
math functions on the expanded views.

When you stop and think about it, it makes things interested.

It's just a way of you seeing more of your information all at once on
the screen.


--
"I'd rather have a bottle in front of me than a frontal lobotomy"

"Daily Thought:

SOME PEOPLE ARE LIKE SLINKIES. NOT REALLY GOOD FOR ANYTHING BUT
THEY BRING A SMILE TO YOUR FACE WHEN PUSHED DOWN THE STAIRS.
http://webpages.charter.net/jamie_5"