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ESC character. See data link escape character.
Extended Attribute Buffer (EAB). A buffer for storing
extended field attributes and character attributes.
extended color. (1) A capability that allows color
tenilinals to display or print fields or characters in
colors using extended field and character attributes.
(2) An attribute type in the extended field attribute and
character attribute.
extended field attribute. Additional field definition to
the field attribute that controls defining additional
properties such as color, highlighting, character set, and
field validation. The extended field attribute is altered
by information passed in the Start Field Extended and
Modify Field orders.
extended highlighting. (1) A function that provides
blink, reverse video, and underscore for emphasizing
fields or characters on devices supporting extended field
attributes and character attributes. (2) An attribute
type in the extended field attribute and character
attribute. (3) An attribute passed between session
partners in the Start Field Extended, Modify Field, and
Set Attribute orders.
field. See display field.
field attribute. A control character stored in the
character buffer in the first character position of a field.
For those devices supporting the 3270 data stream, a
field attribute defines protected/unprotected,
alphanumeric/numeric, detectable/nondetectable,
display/nondisplay, intensity, and modified data tag
(MDT).
field inherit. A bit setting the character attribute which
defaults the character properties to the extended field
attributes or device default if the buffer is unformatted.
formatted display. A screen display in which a display
field, or fields, has been defined as a result of storing at
least one attribute character in the display buffer.
full duplex. See duplex.
general polling. (1) An input technique for remote 3270
devices in which special invitation characters are sent to
a device control unit instructing that control unit to
begin transmission from all devices ready to enter data.
(2) See also polling and specific polling.
*half duplex. (1) In data communication, pertaining to
an alternate, one way at a time, independent
transmission. (2) Contrast with duplex.
host. (TC97) A processor that controls all or part of a
user application network.
inactivity timer. This timer may be configured on
switched connection or EIA 422A connections.
It
is
X-8
3708 Planning and Installation
used to force disconnection of a device after the
specified length of time has passed with no input from a
downstream device. This timer is often used to prevent
excessive telephone charges when a user forgets to
disconnect.
Insert Cursor (IC) order. An order that displays the
cursor at the current buffer address.
intensified display. An attribute of a display field;
causes data in that field to be displayed at a brighter
level than other data displayed on the screen.
keyboard mapping. For an ASCII device attached to
the 3708 in protocol conversion mode, a table that
defines which ASCII keyboard sequences are equivalent
to 3270 functions.
leased line. See nonswitched line.
line control characters. Characters that regulate the
transmission of data over a line; for example, delimiting
messages, checking for transmission errors, and
indicating whether a station has data to send or is ready
to receive data.
Line Quiet Time. Specifies the number of DEL
characters (X
I
7F '), the 3708 should transmit before
transmitting host data after line turnaround. This
ensures that the line has quiesced before host data is
transmitted.
local. Pertaining to the direct attachment of devices by
channels to a host CPU. Contrast with remote.
logical unit (LU). In SNA, a port through which an
end user accesses the SNA network in order to
communicate with another end user and through which
the end user accesses the functions provided by system
services control points (SSCPs).
MDT. See modified data tag.
modem eliminator. For leased lines only, a device that
replaces a pair of modems and communication lines
between two local terminals. Some modem eliminators
provide clocking for synchronous attachment and some
redrive signals. A modem eliminator is a active device
used to connect two DTEs together for communication
purposes. A modem eliminator typically provides
cross-over of required signals as well as redrive
capability of the signals. In many cases, RTS and CTS
delays can be provided by modem eliminators as with
modems. A modem eliminator replaces a pair of
modems and a phone line. Modem eliminators can be
configured to provide clocking also.
modified data tag (MDT). A bit in the attribute
character of a display field, which, when set, causes that
field to be transferred to the channel during a
read-modified operation. The modified data tag may be
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