Paradise Datacom P300-VSAT Installation & Operating Handbook page 206

Text on Display
TX WARNINGS
(Top line of display)
Tx Warn: Reconfiguring Tx path
Tx Warn: Data marginal, clock inv ?
Tx Warn: Line code violations det'
Tx Warn: Transmit FIFO slip
Tx Warn: Backward alarm at Tx input
Tx Warn: TS16 MF Back' alarm at Tx input
Tx Warn: Tx input BER > User threshold
Tx Warn: Framer slipping data to sync
Tx Warn: Framer slipping sig' to sync
P300H
Description / Cause / Notes
Tx Traffic warnings: Deferred alarm relay only
The modem is reconfiguring the Tx path (after a user parameter change).
The phase of the input Clock and Data is checked to ensure the data is stable when it is actually
latched into the modem. This message means that the data is changing at this critical time, and it
WILL CAUSE DATA ERRORS. Check the A & B clock lines are not reversed. (Data A & B should
be stable on the rising edge of Clock B, the falling edge of Clock A)
G.703 interfaces have several different line codes. For 1544kbps they are typically AMI and B 8ZS,
and for 2048kbps they are AMI and HDB3. Normally the LATTER is the one which is used. The
interface must be configured to match the line code of the other equipment, otherwise line code
violations (ie terrestrial data errors) will occur. See Note 3
The FIFO which interfaces the Drop Mux to the Framer has slipped (full or empty). This should
never occur in operation (contact factory).
A Frame Backward Alarm is detected at the Tx Input. This indicates that equipment downstream of
the RECEIVE path has failed and is returning an alarm. This may be due to any receive
downstream equipment, but could be due to the modem Rx output failing. Check the modem Rx
path indicates OK, Check the Rx data output from the modem is connected to the downstream
equipment.
A Multiframe Backward Alarm is detected at the Tx Input, this indicates that equipment downstream
of the RECEIVE path has failed to find multiframe sync and is returning an alarm. The Modem only
detects this alarm when the Tx baseband is set to use the Drop mux in a G.732 mode and CAS
signalling has been selected (or 2048k IBS G.732 0% overhead mode with CAS is enabled). On
the Rx path, if the Insert Mux bearer is set to Generate, then check the Rx path is also utilising
CAS, otherwise it will generate a bearer without a TS16 Multiframe.
The Bit Error Rate at the Tx input (measured on the PCM Frame Alignment Words) is worse than
the user set threshold for a deferred alarm (Change, User-Opt, Thresholds, User BER). This
warning will be replaced with a Fault message at 1x10 . Check the line code setting
(AMI/B8ZS/HDB3) matches the input signal on any G.703 cards in use. See note 3
After a break in the Tx input data, the framer is `bit slipping` data in the Transmit FIFO to bring the
data taken out of the FIFO by the framer into step with the satellite frame timing. It bit slips (rather
than force the frame timing into step with the data) to prevent causing a frame sync loss in the
distant end equipment.
See above text, but this time with regard to CAS signalling data not the main data path.
P300 Series Installation and Operating Handbook
-3
Relays To Terr To Sat Other
D
D
D SB
D SB/SD
(Note 2)
D
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