Siglent 1202X-E Serial Decoding not working

[tv84]

The SDS1202X-E is the bottom of the barrel model of the contemporary product line. It still gives you a lot for the money, like 200 MHz bandwidth and free serial decoders even back then, when no other manufacturer was willing to provide such. From my point of view, Siglent makes this offer just to serve hobbyists on a budget, but certainly don't make much of a profit from that part of their business.

All true, but ruining something that was working in a previous FW version, and let it stay like that, is not the way to do things. Even for the programmer's curriculum...

[nctnico]

It's a pity, but I feel unfair and deliberate bias on the part of the developers towards the owners of the SDS 1202X-E. For their sympathy and support of Siglent, for choosing a two-channel model, they were deprived of the Internet and Wi-Fi. 1202X-E owners are not worthy of the -V2 Operating System, markers and FFT tables; for them there is no need to check the functionality of the firmware. But for that, the owners of the SDS 1104X-E are not deprived of attention. I wonder why that is?

The SDS1202X-E is the bottom of the barrel model of the contemporary product line. It still gives you a lot for the money, like 200 MHz bandwidth and free serial decoders even back then, when no other manufacturer was willing to provide such. From my point of view, Siglent makes this offer just to serve hobbyists on a budget, but certainly don't make much of a profit from that part of their business.

If this where actually true, the tech support would have replied that the serial decoding is crippled/not working instead of suggesting to put dead time between the characters. The latter just shows the tech support (and maybe some people in R&D as well) knows too little about what is required for protocol decoding (and more specifically: how serial / UART protocols work as these typically send data back-to-back).

[vorosj]

I am pretty sure the the V1.3.27_EN firmware UART decoder is simply wrong. It must be a bug, the frame in the decoder line is longer then the actual UART frame, and it fails decoding.

I downgraded to 1.3.26_EN, don't even touched the input signal or settings, and it's working.
(test: 19200, 8bit, 1 start, 1 stop, no parity)

[Mike54]

Hello Marcus and the others,

recently I bought a new SDS1202X-E oszilloscope and was really astonished about the price/feature-relationship of that model...
...until I investigated the UART-decoding feature: I found same problems when decoding UART-signals with 1 stopp-bit (commonly used).
My new oszilloscope was delivered with FW 1.3.27 and I despeately searched for my mistake in wrong settings etc. ...
I tested with Arduinos, Raspberry-pico and serial-signals from my PC - no success.
Shortly before claiming to resend the set, I found this discussion here and successfully downgraded to FW 1.3.26 - now my decoding- problems disappeared.

Thank you very much for this article and discussion! I think, there seems to be a real bug in the actual FW - and not only when decoding ascii "AA".

Generally I am awaiting a new and improved FW-version and hope, that Siglent will care for that!

Greetings from Hamburg/Germany
Mike