Hi @oi18ct,
I apologize for the delay; this clearly dropped off my radar.
Measuring the output of the transceiver (-7 V to 12 V) as well as measuring the 5 V UART/TTL signals either individually or simultaneously, will not be an issue for either the Analog Discovery 3 or the Analog Discovery Pro ADP3450/3250 as they both support a -25 V to +25 V analog input, as well as supporting 5 V digital inputs (neither device supports a 5 V digital outputs).
My understanding is that the modbus protocol is not currently supported by the WaveForms software, though you can add a custom interpreter within the Logic Analyzer as shown here: https://forum.digilent.com/topic/18575-good-day-new-digilent-digital-discovery-user/#comment-48984.
As for which device would be better suited for you, I think it will ultimately come down to how many samples you want to collect within a particular time frame (and price point of course). The Analog Discovery 3 can collect up to 32768 samples per channel on the oscilloscope and logic analyzer (though if using them simultaneously, the best configuration combination would be 16384 samples for each oscilloscope channel and 32768 channels. The ADP3450/ADP has DDR memory and so can collect a lot more samples (32 million for each analog input channel and 64 million for each logic analyzer channel) for you to view in app (rather than recording the data to file, which both devices should be able to support without losing any samples while transferring over USB).
Let me know if you have any questions.
Thanks,
JColvin
