Data Transmission Protocols; Standard Transmission Protocol - HEIDENHAIN TNC 415 Technical Manual

3

Data transmission protocols

The TNC enables data and files to be transferred using different protocols (which can be selected via
the interface setup or the machine parameters).
These transmission protocols can be selected in six different operating modes, as follows:
– ME
– FE1, FE2
– EXT1, EXT2, EXT3
LSV/2
The following applies to data transmission protocols (except LSV/2) :
– If a file which is read in is already stored in the TNC, the message "ERASE/OVERREAD" is
displayed. In this case the TNC aborts transmission with the appropriate handshake and does not
continue transfer until after acknowledgement.
In the event of an attempt to erase write-protected files, the error message "PROTECTED PGM" is
displayed and the dialog "CONTINUE = ENT/END = NOENT ". In this case, either the next file can
be read in or the transfer can be aborted.
– If a file has been read out and the data transfer menu has been terminated with the END key,
the TNC outputs characters <ETX> and <EOT> (or ASCII characters according to setting in
MP5201.x and MP5210.x in operating modes EXT1, EXT2 and EXT3).
– If a transmission is terminated with the END-key, the error message "PROGRAM INCOMPLETE" is
issued.
3.1

Standard transmission protocol

3.1.1 General
This protocol is set as standard in operating mode ME and can also be optionally selected for
operating modes EXT1/EXT2/EXT3 via the machine parameters. In the following, the control
characters which are sent and received with this protocol are listed for the various transmission
alternatives. When outputting a file, the <NUL> character is sent exactly 50 times at the start of the
file. When reading in, however, the control unit ignores this character. Therefore it is of no
importance how often the peripheral unit sends the <NUL> character before the file.
If, however, ME mode is set instead of EXT1/EXT2/EXT3, attention must be paid to the following:
All the programs in a file which end with the end-of-text character <ETX> are stored in the magnetic
tape unit ME.
8-28 TNC 407/TNC 415/TNC 425
Standard transmission protocol to match HEIDENHAIN
magnetic tape unit (7 data bits, 1 start bit, 1 stop bit)
Transmission with Block Check Character and with fixed control
characters (7 data bits, 1 start bit, 1 stop bit)
Freely configurable operating modes: data format, transmission
protocol and control characters can be freely set via machine
parameters
Two-way transfer for TNC diagnostics and remote operation
conforms to DIN 66019. This protocol always runs in the
background of the TNC and is started externally by a PC.
2 TNC data interfaces 01.98