Tait T2000-A75, Operation Manual, Page: 9 / 38

November 2001 M2256-000-00-051 9
2 Changing Modes
In order to change from Command mode to Transparent mode, the PC must send a TRANS-
PARENT command to the A75. Once acknowledged, any further communication is linked di-
rectly to the A75 modem in Transparent mode.
When the TRANSPARENT command is sent to the A75, the escape sequence character that is
used to return to Command mode is also sent.
The escape sequence consists of a 2 second idle time, followed by three escape characters (with-
in 2 seconds), followed by a further 2 second idle time.
If the T201X defaults to Transparent mode at power-up, the escape character is set to the default
value of ‘+’.
Example
1. t is the message [IDENT] for a TRANSPARENT command telling the A75 to go into Trans-
parent mode
2. The [SIZE] parameter in this example is 01 as there is one character of data to follow in the
[PARAMETERS] field.
3. z is the escape character in the [PARAMETERS] field. When 2 second idle + zzz +
2 second idle is detected in Transparent mode, the A75 is forced back to Command mode.
4. The [CHECKSUM] in this example is B1. Refer to the Calculating the [CHECKSUM] sec-
tion for details.
(2s idle) + zzz + (2s idle)
Transparent
mode
Command
mode
t z
[SIZE] [CHECKSUM]
PC(1)
A70(1)
A70(2)
or Tait Orca
RS232 over air
PC(2)
RS232
‘.’
‘.’