In a customer project that i have implemented few years ago, we have selected PicoScope 5204. Back then the requirement was to able to sample the signal for 30s.
Specifications wise, 5204 is able to sample at 8 bit at 1GS/s and its memory 128MS. Table belows shows some simple calculation
| Sample rate | Max time | Calculation Note |
|---|---|---|
| 1GS/s | 0.128s | =128MS/(1GS/s)=128e6/1e9=0.128s |
| 100MS/s | 1.28s | =128e6/100e6 |
| 1MS/s | 128 s -> 2 minutes 8 sec | =128/1=128 |
| 1kS/s | 35 minutes | =128e6/1e3=128ks=128k/60=2133s=35 minuts |
Now, 3 years down the road, my customer ask what is the maximum sample that can be used with the same PicoScope 5204, but he wants to sample for 1 minute. So, the calculation is as below.
| Sample rate | Max Time | calculation note |
|---|---|---|
| 2.1MS/s | 60s | 128e6/x=60, x= 128e6/60=2.1MS/s |
Note
1)a very important consideration when doing this calculation is whether the memory depth has to be divided by all the channels with regards to sampling rates.
2)good explanation from Pico Technology about deep memory oscilloscope https://www.picotech.com/library/oscilloscopes/deep-memory-high-performance-oscilloscopes