P300H
P300 Series Modem Installation and Operating Handbook
Page 57
6.6 CHANGE, TX MENU
The Change, Tx menu is shown below. Note that options 2-5 are only displayed when the
ÍÛÎÊ×ÝÛ
option is set to something other than `Off`, and so initially,
the screen may
only
show the
ÍÛÎÊ×ÝÛ
option.
Tx: 1:Service 2:Baseband
3:Clocking 4:Modulator 5:ESC/Aux/BA
Change, Tx Menu
Taking each of these possible selections in turn:
6.6.1
Change, Tx/Rx, SERVICE Menu
Tx Service: [IDR] 1=Off 2=Closed Network
3=IBS/SMS 4=IDR 5:Custom
Change, Tx/Rx, Service Menu
The options are:
ÑÚÚ
This disables the path completely for Tx or Rx only operation. All alarms for that
path are muted, and traffic faults ignored. For the Tx path the Tx carrier is also
muted.
ÝÔÑÍÛÜ ÒÛÌ
The Tx/Rx path operates in a `Closed Network` mode. If the Async ESC
featureis available (standard P300-IBS and above) then a subsequent screen
(described in the next section) asks if it is normal
Ý´±-»¼ Ò»¬©±®µ
, or whether
Ý´±-»¼ Ò»¬ д«- ÛÍÝ
is required. Normal
Ý´±-»¼ Ò»¬©±®µ
adds no overhead
to the data and is compatible with other closed network equipment such as the
Paradise P200, and closed network equipment from other vendors.
Ý´±-»¼ Ò»¬ д«- ÛÍÝ
adds the lowest possible overhead to the satellite data to
provide whatever ESC rate is selected. When this mode is selected there is
also the option to provide a Backward Alarm facility. Closed Net Plus ESC also
has the advantage that at rates above 32kbps a synchronous scrambler is
used (in place of the error multiplying V.35 scrambler used on normal closed
network links) and, if used with Drop/Insert, the `Timeslot Identity is
maintained`. If you want the backward alarm, synchronous scrambler, or
Timeslot ID Maintenance advantages of Closed Net Plus ESC, but don t want
an ESC channel, simply select the ESC to the lowest Baud rate available (50
Baud), and the rest of the features will be provided within less than 0.5%
overhead.
×ÞÍñÍÓÍ
The Tx/Rx path operates in IBS/SMS `Open Network` mode, where a 1/15th
framing overhead is added to the data. In this mode the Modem is compatible
with other `Open network` equipment such as the P230, P230D/I, OEM
modems used with a P1300 framing unit, or other `Open Network` equipment
from other vendors. Refer to the section "IBS/SMS Service Features" in
Appendix F on page 212 for a full description of IBS/SMS features.
×ÜÎ
The Tx path operates in IDR mode, where a 96kbps framing overhead is added