terminal not ready can mean either the transfer settings are not correct or the cable is not correct or your handshaking method doesn't match the cable type.
you don't need to mess with cnc parameters.
look in the operation manual where it shows the parameters at the back. check the parameters in the
machine and write those down for baud, data bits, stop bits and parity.
set your PC software to the same settings then use PIP to read/punch a simple program.
if the transfer is working but it comes out as junk it means the data bits/stop bits are not correct.
really all 4 things must match on both PC and CNC (baud/parity/data bits/stop bits) and your handshaking
method must match the type of cable you are using (i.e. null modem cable with software handshaking or hard-wired
full handshaking).
If you can't get a known good cable working buy a simple RS232 tester on ebay (the type with LEDs showing RX/TX/DTR/DSR etc)
and test the ports on the machine.
I suggest you read some theory on rs232 wiring and functionality.....
RS-232 - Connecting Devices