D-Channel X.25

Table 12-5: Default X.3 Parameters (Continued)

18

Line display

18

Ctrl R (12H of ASCII Character

 

 

 

Table) is the line display

 

 

 

character

 

 

 

 

19

Editing PAD

2

Editing PAD service signals is

 

service signals

 

generated for display terminals

 

 

 

 

20

Echo mask

64

No echo of edit characters

 

 

 

 

21

Parity treatment

0

No parity check or generation

 

 

 

 

22

Page wait

0

Disabled

 

 

 

 

To save the current X.3 parameter configuration to nonvolatile memory, escape to command mode and enter AT&W

(see Escaping to AT Command Mode in Establishing an X.25 Session). Entering AT&W saves the port and current session configuration as well as the X.3 parameters. The factory X.3 configuration can be restored by entering AT&F. This command also restores port and current session configuration.

CCITT specifies two standard profiles for the X.3 parameter set. The transparent profile is recommended for applications such as file transfers. The transparent profile essentially disables most of the PAD features so that the file can be transferred completely unaltered (no padding, line feed insertion, flow control characters, or service signal messages when transmitted to the DTE). The simple profile is an alternative configuration to the TA’ s default configuration for simple interactive terminal applications. Table 12-6 lists the X.3 parameters and the values supported by the TA.

Table 12-6:CCITT X.3 Parameter Profiles

Parameter

Description

Transparent

Simple

 

 

Profile

Profile

 

 

 

 

1

PAD recall using a character

0

1

 

 

 

 

2

Echo

0

1

 

 

 

 

3

Data forwarding character selection

0

126

 

 

 

 

4

Idle timer delay selection

1

0

 

 

 

 

5

Ancillary device control

0

1

 

 

 

 

6

Control of PAD service and command

0

1

 

signals

 

 

 

 

 

 

7

Action of PAD on break from DTE

0

0

 

 

 

 

8

Discard output

0

0

 

 

 

 

9

Padding after carriage return

0

0

 

 

 

 

12-18

UTA220/UTA220k

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Northern UTA220/UTA220k manual 6CCITT X.3 Parameter Profiles Description Transparent Simple