User`s manual

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CHAPTER 12 TRANSPARENT CODES AND
ADDITIONAL CODES
Transparent codes and additional codes are used during data communication with an external device to send/receive
one-byte data for transmission control on the external device side as user data.
Transparent codes and additional codes are handled in data communication using the non procedure or bidirectional
protocol.
• Transparent code: One-byte data for transmission control.
• Additional code: During transmission, one-byte data added preceding the transparent code and additional
code data. During reception, one-byte data deleted (the immediately succeeding one-byte data is processed
for reception).
12.1 Handling the Transparent Code and Additional Code
Data
The following explains how the Q series C24 handles transparent codes and additional codes during data
communication using the non procedure or bidirectional protocol.
The range of additional code data that is added or deleted is explained in Page 299, Section 12.3 and Page 309,
Section 12.5.
(1) During data transmission
Additional code data is added immediately before the transparent code and additional code data set for
transmission.
(2) During data reception
When additional code data set for reception is detected, the additional code data is removed and the immediately
succeeding one-byte data is processed for reception.
Buffer memory
Transparent
code
Additional
code
Send
Transparent
code
Buffer memory
Arbitrary
code
Receive
Additional
code
Arbitrary
code