SNAX/APN Application Programming Manual

The CRT Interface
SNAX/APN Application Programming Manual—420111-001
2-10
Setting BREAK Key Ownership
(SETMODE Function 11)
This SETMODE procedure call is relevant only to applications sending data to and
receiving data from a terminal device.
Setting BREAK Key Ownership (SETMODE Function 11)
The file system enables a terminal user to signal a running application by pressing the
break key if the application performs its own break handling. If the application does not
perform its own break handling, pressing the break key while the application is running
returns the user to the command interpreter from which the application is started.
Because 3270 terminals do not have the BREAK key, this function is simulated by
another key. On SNA link-attached terminals, the ATTN key is used. On non-SNA
channel-attached terminals, the PA1 key is sometimes used; when the PA1 key is
pressed, ASCII code %H25 is sent to the application. Whether the application interprets
it as a BREAK command is application-dependent.
A process that is enabled for the BREAK function is called the owner of BREAK. Only
one process can own BREAK for a specific terminal at any time. A process does not
automatically become the owner of BREAK when it is started; it becomes the owner of
BREAK by using SETMODE function 11:
param1
0 Disables BREAK function (default).
> 0 Enables BREAK function.
< 0 Gives BREAK ownership back to previous owner.
param2
Terminal access mode after the BREAK key equivalent is pressed:
0 Normal mode (any application that has the terminal open can access the
terminal).
1 BREAK mode (only applications with BREAK access can access the
terminal).
For information on how to establish BREAK access, see Setting Terminal Access
Mode and File Access Type (SETMODE Function 12) on page 2-12.
last-params
allows you to view the most recent option setting. Because the option can also be
set using SCF or SPI, the returned value indicates the setting before this call takes
effect.
You can also fetch the current settings of the BREAK handling parameters; seeSetting
and Fetching BREAK Parameters (SETPARAM Function 3) on page 2-11. The
CALL SETMODE ( filenum , 11 , param1 , param2 ) , ,
[ last-params ] ) ;