Auto Line Feed Mode
USER-DEFINABLE KEYS
Whenever the user keys menu is displayed on the screen the terminal is implicitly in format mode. The menu con-tains a set of unprotected fields that you access using the _ and _ keys.
For each user key the menu contains four unprotected fields:
ATTRIBUTE FIELD. This one-character field al-ways contains an uppercase L, T, or H signifying
Keyboard Control
fO ~~ f~ETURt~
fl
Ii
LRBELI
f2
Ii
LRBEL"
f']
Ii
LRBELI
f4
Ii
LRBEL,
ft:" . .J
Ii
LRBELIi
fE;
Ii
LRBELI-f?
Ii
LRBEL,
f C)
'-'
Ii
LRBEL 1=ErHER
Figure 4-2. User Keys Definition Menu
c. Treated in the same manner as the alphanumeric keys (M). If the terminal is in local mode then the content of the key is executed locally. If the termi-nal is in remote mode and local echo is disabled
(OFF) then the content of the key is transmitted to the host computer. If the terminal is in remote mode and local echo is enabled (OM) then the con-tent of the key is both transmitted to the host computer and executed locally.
The alphanumeric keys are disabled when the cursor is positioned in this field. You change the content of this field by pressing the "MEXT CHO I CE" and "PRE-VIOUS CHOICE" keys ( . . a n d " , respectively).
LABEL FIELDS. The pair of eight-character fields to the right of the word "LABEL" allows you to supply the user key's label. When the terminal is in user keys mode the key labels are displayed from left to right in ascending order across the bottom of the screen (each displayed key label occupies two lines). The first
LABEL field in the user keys menu supplies the upper portion of the particular key label while the second supplies the lower portion. When defining a key label you may use alternate character sets and any of the available video enhancements if you so desire.
KEY DEFINITION FIELD. The entire line im-mediately below the attribute and label fields is available for specifying the character string that is to be displayed, executed, and/or transmitted whenever
the particular key is either physically pressed or programmatically triggered. When entering char-acters into this field you may use display functions mode, alternate character sets, and any of the avail-able video enhancements if you so desire.
When entering the label and key definition you may ac-cess the alternate character sets by way of the "mod i fy char set" function key ( . . ), the display enhancements by way of the "enhance Video" function key
<"},
anddisplay functions mode by way of the "DI SPLAY FUMCTMS"
function key ( , , ) . Note that this implementation of display functions mode is separate from that which is enabled/disabled via the mode selection keys.
Note that when the user keys menu is displayed on the screen the _ key definition is temporarily disabled so that you can Use that key for including~ codes (with dis-play functions mode enabled) in key definitions. If auto line feed mode is also enabled, the _ key will generate a
~LF.
When the user keys menu is displayed on the screen you may use the
III, IB,
andII
keys for editing the con-tent of the label and key definition fields.When you are finished defining all the desired keys, press the . ,
II,
orI!II
key (in all three cases the user keys menu disappears from the screen). Whenever you press1m
the defined user key labels are displayed across the bottom of the screen and the . . - . . user keys, as defined by you, are enabled.Keyboard Control
Defining Keys Programmatically
From a program executing in a host computer you can de-fine one or more keys using the following escape sequence format:
~&f <attribute>(key>(label length>
<~tring length>(label>(string>
The <attribute>, <key>, <label length>, and <string 1 e ng t h > parameters may appearin any sequence but must preceed the label and key definition strings_ You must use an uppercase identifier (A, K, D, or L) for the final param-eter and a lowercase identifier (a, k, d, or l) for all preceding parameters. Following the parameters the first 0-160 characters, as designated by <label length>, con-stitute the key's label and the next 0-160 characters, as designated by < 5 t r 1 ng 1 engt h), constitute the key's defi-nition string. Any display enhancement escape sequences within the key label or definition strings are automati-cally translated into implicit escape sequences by the ter-minaL The total number of displayable characters (alphanumeric data, ASCII control codes such as iii and LF, and explicit escape sequence characters) in the label string must not exceed 16 and in the definition string must not exceed 80_ Also the sum of the <label length>
and <string length> parameters must not exceed 160.
Example: Assign LOG-ON as the label and HELLO USER. ACCOUNT as the definition for the . . user key. The key is to have the attribute "N".
~&f5k6d19LLOG-ONHELLO USER.ACCOUNTIiI particular user key will have no effect unless the terminal 4-8
is in remote mode. A transmit only user key may (when subsequently pressed) invoke a block transfer handshake and append the appropriate terminator to the string.
Controlling the User Keys Menu Programmatically
From a program executing in a host computer you can display the user keys menu on the screen and remove it from the screen using the following escape sequences:
DISPLAY MENU: ~j
REMOVE MENU: ~k
ContrOlling the Function Key Labels Programmatically
From a program executing in a host computer you can control the function key labels display as follows by using escape sequences:
• You can remove the key labels from the screen entirely (this is the equivalent of simultaneously pressing the _ and
I I
keys).• You can enable the mode selection keys (this is the equivalent of pressing the
a
key).• You can enable the user keys (this is the equivalent of pressing the • key).
• You can "lock" the current set of labels on the screen (i.e., disable the
II, a,
and • keys).• You can reenable the
II, a,
and • keys.• You can remove the key labels from the screen entirely and replace them with a message of your own.
• You can remove your own message from the screen and restore the current key labels.
The escape sequences are as follows:
~&jA
Disable the function keys entirely and remove all key labels from the screen.
Enable the mode selection keys.
Enable the user keys. string <message> (which consists of < xx) characters).
-Triggering the User Keys Programmatically From a program executing in a host computer you can trigger the execution of the _ key or a user key by using the following escape sequence:
1i:&1' <0-8) E
where <0-8) identifies the key to be triggered, as follows:
a • 1 •