Table Of Control Characters - HEIDENHAIN TNC 415 Technical Manual

Table of control characters:

Character
SOH
STX
ETB
DC1
DC3
ETX
EOT
ACK
NAK
8-38 TNC 407/TNC 415/TNC 425
Name
Start of Header
Start of Text
End of Text Block
Start data transfer (XON)
Stop data transfer (XOFF)
End of Text
End of Transmission
Positive checkback
(Acknowledge)
Negative checkback (Not
Acknowledge)
2 TNC data interfaces
Description
SOH identifies the beginning of the
data transfer header. This is a
character string that contains the
program number and information
about the type of program and the
transfer mode.
STX identifies the beginning of a
program block.
ETB terminates a data transfer block.
The character that follows ETB (BCC)
is used for data checking.
DC1 starts the transfer of data.
DC3 stops the transfer of data.
ETX is transmitted at the end of a
program.
EOT terminates the data transfer and
establishes the idle state. The
character is transmitted by the TNC
at the end of a program input and to
the external device in the event of an
error.
ACK is transmitted by the receiver
when a data block has transferred
without error.
NAK is transmitted by the receiver
when a data block has transferred
with an error. The transmitter must
re-transmit the block.
01.98