Technically: RS485 is (like RS232, RS422, etc, etc) only an electrical interface specification so you can run any kind of bit pattern over it which forms a communication layer.
However, if there is a UART signal over any of these kind of links you should be able to decode it using the UART decoder. It is a matter of setting the right threshold and polarity (and the regular UART parameters ofcourse).
What is the difference between UART and RS232? You can set a threshold for either mode.
I know what you mean about interface versus protocol etc and I have run e.g. Manchester using RS485 chips, but normally RS422/485 is just a differential version of RS232. The data encoding is the same i.e. NRZ, with a start bit, x data bits, 1 stop bit... To decode this in the correct differential way the scope would need a facility for subtracting two channels, otherwise the decoding is just like RS232.
One thing we could not find today was decoding data on RS422/485 i.e. the difference between two signals. There is one option called RS232, and one called UART which I assume is the TTL level at a microcontroller i.e. inverted version of RS232.
According to
this datasheet, the UART is a bit more configurable.
Many thanks, rsjsouza. There is way more functionality in this than I had realised, or saw in the config pages.
Does the WS3034 have the capability to look at e.g. RS422 the correct way i.e. decode the two signals differentially?
Can you use a maths function to find the difference between the two signals, then run the decode on that result?
Can you use a maths function to find the difference between the two signals, then run the decode on that result?
I would guess it's possible to use "MATH" as a source on a LeCroy. I was surprised by the ancient 9400 and how it allows you to stack operations using "MATH" as a source.
That said, in order to debug RS422/RS485 I think that a differential probe is almost mandatory. Especially with long cable runs. Common mode voltages can be a problem otherwise.
I use a Hameg HZ109 myself. You don't need a lot of bandwitdh.