Configuration Of Interfaces; Control Characters - HEIDENHAIN TNC 426 PB/M Technical Manual

8.3 Configuration of Interfaces

8.3.1 Control Characters

8 – 14
Overview of control characters specific to HEIDENHAIN
Character Designation
SOH Start of Header
STX Start of Text
ETB End of Text Block
DC1 XON
DC3 XOFF
ETX End of Text
EOT End of Transmission
ACK Acknowledgment
NAK Negative
Acknowledgment
Description
Identifies the beginning of the data
transfer header. The character string
contains the program number and
information about the type of
program and the transfer mode.
Identifies the beginning of a program
block.
Terminates a data transfer block.
The character that follows (BCC) is
used for data checking.
Starts the transfer of data.
Stops the transfer of data.
Transmitted at the end of a program.
Terminates the data transfer and
establishes the idle state. This
character is transmitted by the TNC
at the end of a program input and to
the external device in the event of an
error.
Transmitted by the receiver when a
data block has transferred without
error.
Transmitted by the receiver when a
data block has transferred with an
error. The transmitter must re-
transmit the data block.
HEIDENHAIN Technical Manual TNC 426, TNC 430