ZBA Inc
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1.5.8. Packet Example:
If a record data is "ABCD" with STX/ETX, SEQ and CKS enable, assume SEQ is
‘0’ (030H) the send out data is format as:
02H + 030H + "ABCD "+ 03AH + 03H
030H + 041H (A) + 042H (B) + 043H (C) + 044H (D) = 013AH
Checksum = 013AH – 080H=
0BAH
Å
Still greater than 07FH so repeat
Checksum = 0BAH – 080H=
03AH
The Checksum is calculated by adding all data bytes in the packet except
STX and ETX. If the result is over 07FH (ASCII extend) subtract the result by
080H, if the result is less than 020H (ASCII control code) add 020H to the
result. This will make sure that the checksum will be in the range of visually
recognizable ASCII characters.
1.5.
8
ACK/NAK Control
1.5.9. Connection Lost:
If during the communication period there is an extended time where there is no
response, the PDC assumes that the connection is lost as would be the case for
a TIMEOUT. The PDC will display “Connection Lost”.
Ti view the full instructions for Bluetooth® operation, please refer to
Device Setup, Communication.
