All communication must use RTS/CTS handshaking as described
in the Simple Serial Interface Programmer’s Guide, p/n 72E-40451-xx.
If bypassing hardware handshaking, the host must send the WAKEUP
command before all other communication or the first byte of a message
can be lost during the scanner wakeup sequence. Zebra recommends
not bypassing RTS/CTS hardware handshaking.