Echo to /dev/ttyUSB0 produces no results

I'm trying to make a POS thermal printer work with linux. As far as I understand it, I can send data to print directly to the printer throgh a port - it's an RS232 with USB adapter. It gets connected fine, detected as a pl2303 converter and shown to be /dev/ttyUSB0 . Main problem is - contrary to most information I was able to find online, cat ing the file and then echo ing to it (tried many combinations of data and commands) has no results, including nothing being printed. The terminal with cat is just waiting and not showing anyhting - no gibberish, nothing. Echo returns no errors either. Be

Question by Amelia J. on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.