Half/Full
Ot4>lex Modes
Full Duplex operation
is
used with Full Duplex type modems (Bell
103);
Half Duplex mode with Half
Duplex modems (Bell 202). These modes
are
selected
by
a rear
pG1el
switch.
Full Duplex Operation
When
the TELERAY
is
in
Character
mode
G1d
Full Duplex mode, keyed data
are
transmitted;
the
data
will
not go to
the
TELERAY display unless the remote computer echoes
it.
The Serial I/O Request to Send
signal
is
held
ON
in
these modes.
In
the Block
G1d
Full Duplex modes, keyed data goes
to
the
TELERAY
display
G1d
does
~
go to the Serial I/O port. Keyed data
is
transmitted
only
by
the
transmit functions.
Half Duplex Operation
If
the TELERAY
is
in
Character mode ood Half Duplex mode, a local copy
is
imaged
on
the screen as
items
are
keyed and transmitted. The Serial I/O Request to Send signal
is
asserted upon initiation of
keyboard data entry and negated following transmission
of
Line Feed or New Line code.
In
the
Half Duplex
CI'ld
Block modes, the Request to Send signal
is
asserted only during a
blocl<
trans-
mission. Keyed
data
goes only
to
the
TELERAY display and can
be
transmitted only by the transmit
function.
Local/Remote Modes
In
Local mode
the
TELERAY keyboard and programmable functions
are
executed within the TELERA
Y.
No
data
is
transmitted and the Request to Send and
Data
Terminal Ready signals
are
negated. The Print
function will
operate
in
Local mode.
In
Remote
mode these signals
are
determined
by
Full/Half Duplex
mode
CI'ld
keyed data
is
transmitted as determined
by
the
Full/Half Duplex and Character/Block modes.
COMMUNICA
nONS
CHARACTER
MODES
One/Two
Stop
Bit Modes
These rear panel switch selected modes determine if one or
two·
stop bit(s) will be appended
to
each trans-
mitted
character.
Pcrity
EnoblelDisable Modes
The parity EnabieiDisabie switch enables and disables both the parity generation and
the
parity checking.
If
parity
is
disabled a parity bit will not
be
generated
G1d
the.communications
character,
which
is
trans-
mitted,
will be one bit shorter than
the
character
transmitted when parity
is
enabled.
Seven/Eight Bit Modes
The 7 bits or 8 bits switch controls the length of
the
communications
character
excl~sive
of
the
parity or
stop bit positions.
When
set
to 8 bits the TELERAY will automatically put a I
in
the
8th
bit position
on transmission and will ignore
the
8th
bit on reception.
Conmonly
Used Convnunicotims
Character
Mode Settings
Parity
Odd Set
to
Parity ENABLE, 7 Bits, I or 2 Stop Bits
Parity
Even Set
to
Parity ENABLE, 7 Bits, I or 2 Stop Bits
Parity
High Set
to
Parity DISABLE, 8 Bits, I or 2 Stop Bits
No Parity Set
to
Parity DISABLE, 7 Bits, I or 2 Stop Bits
NOTE: The combination of Parity Enable ood eight bit modes should generally be avoided.
BaudRotes
The Serial I/O baud
rate
can be changed from
tfole
rate
selected
on
the
rear panel baud
rate
switches
to
any other of
the
fifteen available
rates
by
an
ESC
C followed
by
the
appropriate
character
shown
in
Table
2. Once changed, the baud
rate
remains fixed untir it
is
changed again, until a
Reset
to
Initial
State
sequence (ESC
g)
has been initiated, or until power
is
turned off.
In
the
latter
two cases,
the
rate
reverts
to
the
rate
set
by
the
rear
pG1el
switches. The peripheral baud
rate
can be changed to any of
the
other
fifteen available
rates
by an
ESC
\ followed
by
the appropriate
character
shown
in
Table 2. Once
changed, the
rate
remains fixed until it
is
changed again, or until power
is
turned off,
in
which case
the
rate
reverts
to
the
rate
set
by
the
rear
panel switches.
4
