Update 1: I tried anew with my scope and here are a few details that I found. I connected the probe to pin 4 and the ground clip to pin 5 (I thought that since the POD2 was floating w.r.t. the scope this should not be a problem and indeed it wasn't).

I found the signals attached here. This is one burst of what I think are four bytes. If that's correct, the left part shows bytes 1-3 and the right part shows bytes 2-4. The edges are 16 us apart. The short duty cycle lasts 1 us, the long one 3 us.