PC to CPU:
'STX' 'ADR' 'T' 'CHK' 'ETX'
'T'
ASCII-Code 0x54 OR 0x80 = 0xD4
CPU to PC
'STX' 'ADR' 'T' date time 'CHK' 'ETX' (set value)
'T'
ASCII-Code 0x54 OR 0x80 = 0xD4