This is just a one time use for a project. I'll expect to only make a few dozen sets of measurements. I'm hoping to avoid building custom hardware/code to do it. The waveform in question is also not a square wave so I would ideally like to capture the first cycle or two on the scope and also the duration (or number of cycles).
I haven't used labview in many years and don't have a working setup so that would probably take too much time. Perhaps the easiest way is to build a circuit that will trigger the scope at the beginning and end of each sequence. I was hoping one of the new rigol scopes might have some capability to do this without external trigger. Posted on: November 21, 2013, 08:04:19 08:04 - Automerged
if this is a single task: use a USB-based logic analyzer.
A Saleae-(or-a-clone)-LA has plenty of (disk-)space to capture the whole thing and
analyze frequency and duration.
If necessary use a amplifier and a schmitt-trigger to deal with the changing amplitude.
I may be able to convert the signal into a pulse or square wave of the same frequency. Does their software do automatic analysis of the capture to measure frequency and duration? Something like (frequency, duration) or time index showing when the frequency changes? If not, would it be practical/possible to scroll through up to a half hour worth of captures (even at very low sample rates like the lowest of 25 khz) to look for the time indexes when the frequencies change? (At 25 khz sampling rate, that would be 45 megasamples in 30 minutes)
45 megasamples...the Rigol DS2102 has a 56 megasample memory. I wonder if the sample rate can be set low enough for the 56 msa to cover 30 minutes...I only need to measure frequencies up to about 1 khz. My TDS754D can be, but it only has 8M memory depth. Have any of you tried to scroll through a huge capture buffer like that on the rigol scopes (or with their software on the PC)?