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I
TERMINAL CONTROL FUNCTIONS
I~
INTRODUCTION
NOTE
The 2641A terminal does not have an
(3
key. Therefore, you must press
©
8
ru::o
(in ASCII mode to produce the
code equivalent to the Escape key.
The ESC & k is followed by one or more groups of state and
key parameters. The state is a 0 or 1 to indicate that the
key is to be up or down respectively. The key is a single
letter a, b, or c. The groups can be in any order (
c:;;J
c=J
LOCK
can come before
~:
). The last key letter in the sequence
must be capitalized to indicate the end of the sequence.
Example: Set
c;=JLTF
O
up and
c:;;J
down.
LOCK
•
Programmable Soft Keys (F1-F8)
•
Keyboard Interface Switch Settings (A-Z)
This section describes how to programmatically change
most of the terminal's control settings and perform vari-
ous other control functions. The settings consist of the
following:
•
Latching Keys
c;;J,
~
, c:;;J
LF
MODE
LOCK
ESC
&
k 0
a
1 C
An invalid character (any character other than 0,1, a, b, or
c) will cause the entire sequence to be ignored. An
improper setting, (0 b when the terminal is operating in a
multipoint configuration) will cause only the invalid
setting to be ignored. The rest of the sequence will be
accepted. If the terminal is initialized while configured for
multipoint operation, the
~
key will be read as down
regardless of the switch's physical setting.
When the terminal is powered on or reset, the states ofthe
various keyboard and internal switches are stored in
memory. Most of these stored settings can be changed
programmatically without physically changing the switch
setting. (Note that if the terminal is reset the terminal
will return to the physical settings.)
KEYBOARD INTERFACE SWITCHES
The switches on the Keyboard Interface allow you to alter
terminal operation for specific applications. Table 2-1 con-
tains a summary of the switches and their function. A
more complete description of the switches is given in
Section VII, pages 7-18 through 7-24.
ESC & k <state> <key> ...
LATCHING KEYS
.Three of the mechanically latching keys,
c::;;;J ,
~
,
c=J
IF
MODE
and
CAPS
can have their electronic state changed pro-
LOCK
grammatically. The escape code sequence is as follows:
You can select a specific operating configuration from
within the application program. This eliminates the prob-
lem of requiring the terminal operator to make the set-
tings before continuing with the application program. It
also allows individual programs or even subroutines to
change terminal configuration for a specific function and
then return the terminal to the original state before pas-
sing control back to the main program.
{
0 (clOSed)}
<state> is
or
1 (open)
<switch> is {A through
z}
less I and 0
The switch settings are made using the following
sequence:
ESC & s < state> <switch>
where:
In certain operating configurations (i.e. multipoint), some
switch settings cannot be changed. If attempted, the new
setting for the switch will be ignored.
Example: Set switches A, B, and D open and switch C
closed.
An invalid character in the sequence will cause the entire
sequence to be ignored. The sequence must be terminated
with an upper case switch character. A full reset will
cause the terminal to return to the physical settings of the
switches. Switches Sand T cannot be changed if the ter-
minal is configured for Main Channel protocol.
ESC &
5
1
a
1 b 1 dOe
a (AUTO LF)
I
or
< key> is b (BLOCK MODE)
or
c (CAPS LOCK)
{
o
(up)
}
< state> is
or
1 (down)
where:
3-1
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