SNAX/APN Application Programming Manual

The ITI Interface
SNAX/APN Application Programming Manual—420111-001
3-6
Setting and Fetching BREAK Parameters
(SETPARAM Function 3)
Setting and Fetching BREAK Parameters (SETPARAM Function 3)
Like SETMODE function 11, you can use SETPARAM function 3 to set parameters for
BREAK handling. In addition, you can also use SETPARAM function 3 to fetch the
current settings of the BREAK parameters, and to set the value of a 32-bit BREAK-tag.
SETPARAM function 3 has the following syntax:
param-array and last-param-array are both 8-byte integer arrays containing:
array[0] the equivalent of param1 in SETMODE function 11.
array[1] the equivalent of param2 in SETMODE function 11.
array[2] the most significant word (high word) in the BREAK tag.
array[3] the least significant word (low word) in the BREAK tag.
array[2] and array[3] together form the 32-bit BREAK tag, which is saved by
the I/O process handling the 3270 terminal. The purpose of the tag is to support
applications that own BREAK on several subdevices at the same time. Appropriate use
of BREAK tags allows such applications to distinguish among BREAK messages
received from any of the subdevices.
When you press the BREAK key, a Break-on-device system message containing the
BREAK tag is sent to the owner of BREAK. (The message is sent to the $RECEIVE
file; the owner of BREAK checks the $RECEIVE file for a Break-on-device system
message.) The Break-on-device system message, sysmsg, is composed of an array of
words as follows:
sysmsg[0] -105, indicating that it is a Break-on-Device system message.
sysmsg[1] File number of the receiver’s open file to the device that
indicated break (or -1 if unavailable). The device must be
open.
sysmsg[2,3] The 32-bit BREAK tag value specified with SETPARAM
function 3 (if used).
CALL SETPARAM ( filenum , 3 [ , param-array , 8
[ , last-param-array , 8 ] ] ) ;