P300H P300 Series Modem Installation and Operating Handbook Page 201
APPENDIX E: CUSTOMER SPECIFIC FEATURES
This appendix lists t he cus tomer specific options available on the P300 Series Modems:
Refer to the Change, User-Opt, Operation menu, section 6.10.8 on page 106 for explanations of how to
use these parameters:
RELAY MODE SETTING
0 Default (normal) rel ay operation.
1Cable & Wireless (Alarms Summ ari se)
This feature remaps the external alarm relays to summarise the Traffic & Unit faults. Normally
these are separated as Traffic faults relate to faults external to the equipment (Prompt Traffic) and
Unit fault s re late to faults within the equipment itself (Prompt Unit Fault). When this option is
selected the three fault relays map as follows:
Prompt Unit Fault: Any unit fault or Tx traffic fault (ie Tx summary alarm)
Prompt Traffic Fault: Any unit fault or Rx traffic fault (ie Rx summary alarm)
Deferred Fault: Function unchanged from normal
2Tx Carrier On/Off indication (Software >=V2.12)
This feature provides a form C relay contact to indicate the Tx carrier On/Off state. It may be used
to indicate which one of a 1:1 pair is on-line and which off-line. When active the “Deferred Alarm”
output becomes instead a Tx carrier On/Off indi cati on, mimicking the operation of the Standby LED
on the front panel. `Carrier On` corresponds to the no alarm condition, and `Carrier Off`
corresponds to the alarm condition. When used to indicate whi ch one of a 1:1 pair is on -line, should
both Tx carriers mute (eg an external inhibit applied to both modems in a 1:1 pair), then the
deferred relays of both units would indicate the off condition.
3P300 Clock mode selection (P300i/P310i mo dem/router only, Software >=3.41)
Normally the P300i/P310i data input is internally coupled directly to the output of the internal Linux
router. In this mode the Tx & Rx clocking modes for the modem are fixed (as the Ethernet port or
the router has no concept of clock direction). However under certain circumstances the internal
link from m odem to router is broken and routed through a new rear connector (eg to insert a
Crypto). In such modes it is again useful to have manual selection of the clocking modes for the
modem, and activating Relay Mode 3, re-instates the clock mode questions on t he modem front
panel dialogue.
4L-Band 1:1 Switching - DC & References. (P310 L-Band modem only, Software >=3.62)
In a 1:1 L-Band system, if the modems are configured to supply DC and/or the 10MHz reference
`up the coax` to a BUC or LNB, then when a 1:1 changeover occurs, the modem which becomes
the standby switches off the DC & Reference feeds and these are now supplied by t he new On-
Line modem (which switches them on). This is the NORMAL s t ate, without this relay mode active.
This assumes the L-Band feeds are split/combined through an L-Band splitter/combiner which
passes the DC and reference out of the common port from either split port.
When this relay mode is active, the modem s DO NOT SWITCH OFF the DC & Reference when
in standby, to accommodate 1:1 systems where each modem is coupled to one of a redundant pair
of BUC’s or LNB’s. This means that both BUC/LNB’ s cont i nue working whichever modem is on-line
(however the standby modem does of course inhibit the Tx carrier). Obviously if a splitter /
combiner as described above is used with this Relay Mode active, then the two slightly different
frequency 10MHz references will beat together, and cause the common BUC/LNB to fail.
5-15 Undefined at present