RRX, MK3 and MK4 now use the async protocol.
RRX, MK3 and MK4 now use the async protocol.

Tested on RRX for 8 hours without any issues.

stb-tester/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester