• P ress the Bid key. This transmits a (§) signal
to the other terminal on the line (Figures 5
and
6).
Upon receipt of the
(B)
signal, the re
ceiving terminal automatically switches to r e
ceive status provided the terminal was originally
in standby status. This change to receive status
causes the keyboard to remain locked and the ter
minal motor to be turned on. If this terminal is
operating in local mode or is not in standby status
when the (B) signal is received, an audible alarm
is automatically sounded at the terminal.
Once the initiating terminal acquires the line
through use of the Bid key, it automatically
switches to transm it status. In conjunction with
this, the Transmit light is turned on, the key
board is unlocked to permit the transmission of
text, and the terminal motor is turned on. This
terminal can now transmit a message (or mes
sages) of any length and retain control of the line
until it signals an End-of-Transm ission (EOT).
• P ress the EOT key. This transmits an EOT (5)
signal to the receiving terminal. Both terminals
(the transmitting, as well as receiving) switch
to a standby status. The Standby light at both
terminals is turned on, the keyboards are locked
(except for the Bid key and EOT key), and both
terminal motors are turned off.
Receive
The initial requirement for this terminal is that it
be in standby status. In order to have Status, the
terminal and data set must have power supplied, and
the terminal must be in communicate mode with
paper present in the typewriter.
• Receipt of the
(B)
signal switches this terminal
to receive status (Receive light on, keyboard
locked, and motor turned on). The terminal re
mains in this status until an EOT signal is re
ceived (see Figures 5 and 6). However, if this
terminal runs out of paper while receiving, or
drops status for any other reason, it switches to
a no status condition (all status lights off, key
board locked, and still in communicate mode).
Until this condition is corrected (by inserting
paper or deactivating the paper presence contact)
and the line connection is re-established, the
terminal is unable to receive any further trans
missions. Thus, a procedural requirement pro
viding for message retransm ission when this
occurs should be established for each system.
• Receipt of the EOT signal switches this terminal
to standby status (Standby light on, keyboard
remains locked except for the Bid and EOT keys,
and the terminal motor is turned off).
• If this terminal is in the local mode or is in
communicate mode but out of paper when the
(B)
signal is received, an alarm sounds at this ter
minal. The operator should now switch to the
communicate mode (by positioning the
Communicate/Local key to Com), or insert paper
(or deactivate the paper-presence contact).
Message reception is not possible until this is
accomplished.
Broadcast Operation
This operation (without any special features in
stalled) is essentially the same as a point-to-point
Terminal
Bid Key
EOT Key
©
Text
Ó
Bid Key
EOT Key
©
Tex,
Ó
NON-.SWITCHED
LINE
Terminal
Text
or Multiplexor
from
from
Multiplexor Multiplexor
Figure 5. Point-to-Point Operation (No Special Features)
1 2
