Instructions

ASCII Protocol 6 (26)
3 ASCII Protocol
The ASCII protocol is used to pack data (CAN messages) and commands for the transfer over
Ethernet TCP/IP network.
The ASCII-Protocol in Version 2.0 supports 6 different message types:
• Messages (both directions)
• CAN Commands (from client to server)
• Device Commands (from client to server)
• Events (from server to client)
• Responses (from server to client)
• Ping Request
Commands have to be confirmed. Before a new command can be transmitted an answer has to
be received.
3.1 Basic Message Format
Basic Rules of ASCII Protocol:
• Messages are coded with ASCII characters exclusively.
• Valid characters:
– letters from a to z (no national characters)
– no distinction between upper and lower case
– numbers from 0 to 9
• Messages start with a valid ASCII character and are terminated dependent on the settings in
the CAN-Gateway Configurator with
\r\n, \r, or \n (End-Of-Line).
• Directly after End-Of-Line the next message can follow.
• Messages containing invalid characters are discarded.
• Message contents (e.g. CAN identifier, CAN data) are noted in HEX notation. Other formats
are not supported. HEX specifier (0x...) is omitted.
• ASCII protocol message consists of groups of ASCII characters, each group separated by a
space character (0x20).
• More than one consecutive space characters (0x20) are reduced to a single space character.
• No space characters before and after a CAN message
• The groups of ASCII characters describe different types of messages or commands contained
in the ASCII-Protocol message.
• The single characters of an ASCII-Protocol message are transmitted over the TCP connection
in readable order; beginning with the “message type” group of ASCII characters and ending
with the termination \n.
CAN@net NT 200/420 Software Design Guide
4.02.0332.20000 1.5 en-US