I have a similar problem like yours:
I work with the hydra databucket 2635A and I have to use the file_tx instruction for getting the data(files) from the memory card. I was able to use the log_bin instruction. I got the correct data, but if I use file_tx I just receive some \18...\b.
What I cannot get is, that both instructions are xmodem-transfers, but the file_tx does not provide data.
How did you solve this problem?
I could not download the last link with the VISA-vis.