Communication Configuration Description - IBM 5294 Setup Procedure

Communication Configuration Description
The descriptions for communication configuration
differ for both SDLC and X.25.
SOLe - Field 3
The communication bits (switches) may be displayed
on line 22 of the display screen of any attached
display station. A definition for each bit follows:
0000000000
I I
Bit 1 Bit 10
Nonswitched or Switched (Bit 1)
This bit indicates if a switched or nonswitched com-
munication line is being used. When a switched line
is used (1, on), the DTR (data terminal ready) line will
drop in order to disconnect a call and is not turned on
again until the DSR (data set ready) line is turned off.
Half-Duplex or Full-Duplex (Bit 2)
This bit sets the work station controller for the type of
communication facility (line) used. When set for full-
duplex (1, on), a continuous CTS (clear to send)
signal is permitted, and the RTS (request to send)
signal is always on, if bit 3 is set to point-to-point.
Multipoint or Point-to-Point (Bit 3)
This bit is set to indicate that the work station con-
troller is connected to a multipoint or to a point-to-
point communication line to the host system. The
setting is off (0) for multipoint or on (1) for point-to-
point.
NRZI or NRZ (Bit 4)
This bit selects either NRZI (non-return to zero
inverted) or NRZ (non-return to zero) SDLC trans-
mission coding options. These options are used to
keep the loss of synchronization between the
modems to a minimum. All stations communicating
with each other on a network must use the same
coding option.
The initial setting of this bit is recommended to be
NRZI (0, off) for the EIA interface with analog
modems/DCEs and NRZ (1, on) for DDSA, XLCA, and
EIA interfaces, when EIA is used with digital DCEs.
DTR or CDSTL (Bit 5)
This bit controls the protocol used between the work
station controller and the modem to prepare or
answer a call.
o
=
off, DTR (data terminal ready). Most
modems/DCEs permit the DTR line to be on if the
DSR (data set ready) line is off.
1
=
on, CDSTL (connect data set to line). The
modem/DCE needs the CDSTL turned on when:
• The work station controller takes control of the
line to make a call, or
• The work station controller responds to the RI
(ring indicator) signal or DSR (data set ready)
signal being on and answers a call.
Leading Pad Required (Bit 6)
This bit is set on to cause the work station controller
to transmit a pad character before the leading flag of
each frame of a sequence of one or more frames.
The pad character is hexadecimal 00 and should be
used with the NRZI mode for modems/DCEs that
require a leading pad for synchronization.
IBM LPDA Modem Attached (Bit 7)
This bit is set on to indicate that an IBM LPDA
modem (or a modem having the same functions) is
attached. LPDA modems are: 386X and 383X.
Local Loopback (Bit 8)
This bit is set on
toi~d1cate
that the attached DCE
will enter localloopback mode when the Test Control
1 line is active.
Remote Loopback (Bit 9)
This bit is set on to indicate that the attached DCE
can cause the remote (host system) DCE to enter
remote loop back mode when the Test Control 2 line
is active.
Test Indicate (Bit 10)
This bit is set on to indicate that the attached DCE
will turn on the Test Indicate line when the DCE is in
the test mode.
Appendix A. IBM 5294 Setup Form 57