It’s by design that the READY signal doesn’t appear during remote control.
To get the READY signal in remote control:

1. Set TRIG:TEST:SOUR BUS.
2. Use INIT:TEST to enter the WTG (Waiting For Trigger) state. The READY
   signal will appear at this point.
3. Use TRIG:TEST to start the test.

Please read the communication interface manual for more details.