TUNNELESCAPE

Breaks out of an established tunnel

Platform:

OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720, PwrPak7, CPT7, CPT7700, SMART7, SMART2

The tunnel escape sequence feature allows you to break out of a tunnel between two ports by sending a predefined sequence of bytes through the tunnel in-line with the data stream.

Use the TUNNELESCAPE command to specify the tunnel escape sequence. The escape sequence is applied independently to all active tunnels. Use the SAVECONFIG command to save the escape sequence in case of a power cycle.

This command is used to define an escape sequence that, when detected in a byte stream between any two COM (or AUX) ports, resets the interface mode to NOVATEL NOVATEL on those ports. The baud rate and other port parameters remain unaffected.

The TUNNELESCAPE command accepts three parameters. The first is the switch parameter with ENABLE or DISABLE options. The second is the length parameter. It is a number from 1 to 8 and must be present if the switch parameter is set to ENABLE. The third parameter, esc seq, consists of a series of pairs of digits representing hexadecimal numbers, where the number of pairs are equal to the value entered for the second parameter. The series of hexadecimal pairs of digits represent the escape sequence. The receiver detects a sequence in a tunnel exactly as it was entered.

For example, the command TUNNELESCAPE ENABLE 4 61626364 searches for the bytes representing “abcd” in a tunnel stream. TUNNELESCAPE ENABLE 3 AA4412 searches for the NovAtel binary log sync bytes.

You must first set up a tunnel. For example, create a tunnel between COM1 and COM2 by entering INTERFACEMODE COM1 TCOM2 NONE OFF. The commands can be entered in any order.

All bytes, leading up to and including the escape sequence, pass through the tunnel before it is reset. Therefore, the escape sequence is the last sequence of bytes that passes through the tunnel. Configure the receiver to detect and interpret the escape sequence. For example, use this information to reset equipment or perform a shutdown process.
The receiver detects the escape sequence in all active tunnels in any direction.
Create tunnels using the INTERFACEMODE command.

Message ID: 962

Abbreviated ASCII Syntax:

TUNNELESCAPE switch length escseq

Factory Default:

TUNNELESCAPE disable 0

ASCII Example:

TUNNELESCAPE enable 1 aa

Field	Field Type	ASCII Value	Binary Value	Description	Format	Binary Bytes	Binary Offset
1	Command header	-	-	TUNNELESCAPE header This field contains the command name for abbreviated ASCII or the message header for ASCII or Binary.	H	0	-
2	switch	DISABLE	0	Enable or disable the tunnel escape mode	Enum	4	H
2	switch	ENABLE	1	Enable or disable the tunnel escape mode	Enum	4	H
3	length	1 to 8		Specifies the number of hex bytes to follow	Ulong	4	H+4
4	escseq			Escape sequence where Hex pairs are entered without spaces, for example, AA4412	Uchar[8]	8	H+8

If using the SAVECONFIG command in NovAtel Connect, ensure all windows other than the Console window are closed. If open, NovAtel Connect also saves log commands used for its various windows. This results in unnecessary data being logged.