Digital Channel Triggering.

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jstanchev
Newbie
Posts: 0
Joined: Tue May 09, 2017 6:17 am

Digital Channel Triggering.

Post by jstanchev »

Hello,
Why can't use analog triggering options for digital channel?
For digital channel i have only "LOW" "HIGH" "RISE" and "FALL".
For analog channel i have more and advanced modes ex. "Advanced edge" "Pulse width" "Interval" and etc.
Do You can add options to select digital channel in analog trigger modes?
Greetings.

Gerry
PICO STAFF
PICO STAFF
Posts: 1145
Joined: Mon Aug 11, 2014 11:14 am

Re: Digital Channel Triggering.

Post by Gerry »

Hi jstanchev,

There are only 2 interpreted values in a digital signal, just 1 and 0, and the digital channels are only meant for digital signals. This means that the only objective for the digital channel is to determine whether the input signal is at the voltage level for 1 for 0, (or if it has transitioning between the 2). The Digital channels are typically used for things like capturing the data on a bus at a particular instance in time.

However, although the digital values read are just 1 and 0, the digital inputs are setup in the software to trigger on analog values that have crossed a switching level. The analog switching levels for 1 and 0 are different for different types of Logic (e.g. TTL, PECL, LVDS), as are the transmission methods (e.g. single-ended switching, differential signalling) so you can select what type of Logic you will be triggering on when you enable the digital channels. Once set the digital channels should have no problem triggering as long as you are not using too high a bit-rate, using sufficient quality cable that is not too long, and don't have any detrimental sources of noise or interference nearby.

Analog triggering options are for continually varying signals that potentially have a huge number of different values, different shapes and different durations. For this reason there are more advanced triggering options for creating trigger events out of the different analog signal types and different conditions under which they occur.

Note that, you can use Digital Channels in advanced triggers to build combination logic triggers, from the digital conditions of 1, 0, rising or falling.

Regards,

Gerry
Gerry
Technical Specialist

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