Modes Of Transmission; Character (Conventional) Transmission - Beehive International B150 Series Operator's Manual

abled. Use of the Block mode feature differs from
message preparation Off-Line by the fact that the
terminal receiver is enabled in Block mode.
3.7 MODES OF TRANSMISSION
NOTE: The senes terminals transmit data
only in lower ciliaracters, unless the alpha
lock key is ON during transmission.
3L7.1 Character (conversational) Transmission
During character transmission, the terminal must
be on line. Received alphanumerics are stored in
memory and displayed. Received Control codes
or Escape codes cause the unit to perform the
appropriate function and are not stored in memory
or displayed. In Full Duplex operation, Control
codes and Escape Sequence codes are transmitted
but are not acted upon unless echoplexed back to
the terminal. In Half Duplex mode. Control codes
and Escape Sequence codes are transmitted and
acted upon. In FORMAT MODE, the cursor cannot
enter the protected fields established by the de
limiter codes, therefore, only the data in the un
protected fields are transmitted. In Character
mode, all data are transmitted.
3.72 Block Transmission (Line or Page)
Block Transmission is used to allow the operator to
prepare data and then transmit the data as a unit.
The transfer can be initiated either from the key
board or the I/O. A Block Transfer is initiated from
the keyboard by depressing the SEND key (un-
shifted for Page mode or shifted for Line mode). A
Page Mode Transmission may be initiated from
the I/O by sending an ESC-1. Line Mode Trans
mission is accomplished by sending an ESC-i. When
the Page Mode Transmission is actuated, the cursor
returns to Home, the Request-to-Send line is actu
ated, and the terminal waits for approximately 30
milliseconds and a Clear-to-Send to come true.
The terminal the^ issues an STX as the start of mes
sage delimiter rnrJ begins transmission. Transmis
sion begins at the Home position and the cursor
advances one position to the right after each char
acter is transmitted. If not in the FORMAT MODE,
a two-character sequence (Carriage Return and Line
Feed) is issued whenever the end of a line is encoun
tered. All NULL codes residing in memory are not
transmitted. When the cursor reaches its original
position End the charscter is transmitted, the termi
3-5
nal issues an ETX code to indicate the end of the
message. The terminal then waits approximately
30 msec, drops the Request-to-Send line and en
ables the keyboard. If in FORMATMODE, only the
unprotected data fields are transmitted and an
ASCII Horizontal Tab (HT) code is transmitted at
the end of each unprotected field. Also, in FOR
MATMODE, the CIVLF sequence at the end of each
line is suppressed.
In the Line Send Transmission Mode, the operation
is essentially the same as described above. However,
the cursor is returned to the first position of the
current line instead of the Home position before
the transmission is started.
3.73 Auxiliary Character Transmission
Conversational Mode (character-by-character)
transmission can be accomplished out the AUX
PORT by depressing the alternate action AUX
EN/\BLE key on the keyboard. Then, if the termi
nal is in one of the conversational modes (HDX or
FDX), any alphanumeric keys depressed on the key
board will cause transmission of the associated code
out the AUX PORT instead of the Main I/O Port.
A block transmission for the Main Port will over
ride this AUX ENABLE switch for the duration of
the message.
3.7.4 Auxiliary Port Block Transmission
This transfer can be initiated from the keyboard or
the I/O Port. A page-type transmission out the
AUX PORT is actuated by depressing the AUX Send
key on the keyboard or by sending an ESOO (zero)
sequence into the I/O Port. Delimiters may be sent
in four positions during this page transmission:
Start of Message, End of an Unprotected Field,
End of Line, and End of Message.
3.8 BAUD RATE SELECTION
Transmission rates for the main I/O Port are rotary
switch selectable at the rear of the terminal. This
rotary switch has sixteen positions which select the
normal fifteen baud rates and an externally supplied
baud clock. The rates internally available range
from 75 to 19200 baud.
3.9 FORMAT MODE (Optional Feature)
The FORMAT MODE is selectable from the Key
board or from a remote data source initiated by
an Escape Sequence (ESC W). In the FORMAT
MODE, the terminal display has Protected Fields