I have a device which uses a serial connection to a module. There is a problem where the module stops responding to commands, and stops sending its data. This can be after many hours.
What I’d like to do is capture the data with a probe, so I can see the last few transactions between the devices. Is there a way to do this in Logic 2?
The data could be up to ~40Mbytes in total over a session, but I don’t know when the fault will trigger.
If this is easily achievable I’ll be ordering a Logic Pro.
@jcurtis This is possible with our Logic Pro devices!
As for the length of a capture that’s possible in a single session, this will depend on the amount of available RAM on your PC since the device streams recorded data directly to RAM.
I ran a quick test (1 digital channel recording 115200 baud serial data) for 3 min. This consumed roughly 42 MB of RAM as reported by the software.
This can be extrapolated (not to an exact science) to equate to roughly needing 1GB of RAM per hour of recording 115200 baud serial data.
The only limitation is that our software cannot be configured to trigger when a communication fault occurs, so this will need to be manually searched for once the recording has finished and the faulty has been noticed.
In fact, you can try a demo mode of our software, which can simulate serial data being recorded. Our software can be downloaded below, and the demo mode can be used when a device is not connected:
Finally, in case it helps, when purchasing directly through our website (https://www.saleae.com/), we do offer a 180 day return policy (detailed here: Returns & Warranty | Saleae). If you find that after purchase, our device doesn’t meet any specific requirements you have, you can return your device to us for a refund.
Thanks, that’s great. My lab PC has 64Gb RAM, so no issues there. Finding the last data will be easy, as the module stops, so it will be the last data set recorded. It’s bursty packets and at 115200 this should work well. If needs be I can stop and restart the recording from time to time until the fault appears
I did order a 8 Pro today in the hope it would be possible. With enough ram I can get the tx and rx recorded to try and see what’s happening.
Just to close this off. Logic 8 Pro arrived, and is hooked recording the data. Looks to be doing exactly what I wanted it to do.
I’ve given it an 8 Gb buffer, as I’m recording from 4 devices simultaneously. Which in itself is quite handy and I can see the timings between data being sent and received. The module that locks up is a BLE radio.
Impressive little box.
