RES-NAK Defaults

RES: (Reset)	EOT (0x04)
REQ: (Request)	ENQ (0x05)
STX: (Start of Text)	STX (0x02)
ETX: (End of Text)	ETX (0x03)
ACK: (Acknowledge)	ACK (0x06)
NAK: (Negative Acknowledge)	NAK (0x15)