TC12 Installation, Commissioning & Maintenance Handbook
b) 2 wire system but with 4 wire selected in error:
No reply message will be received. Only the yellow LED for the modem will come
on.
(4) SW5 -
on LED will
2.4.4 Transformer PCB
the switch is set On when there is an OTU on the line then no Control message
will be sent to the OTU.
ffect
.
2.4.5 Effect of Incorrect Switch Settings on the Digital Output PCBs
PCB addresses are duplicated on one or more boards, the outputs on each
2.4.6.1 UTC TCC Co mmunication Problems
tion of PC Ethernet card or cables or
lure.
Ethernet cable/cable not attached.
A 50 Ohm termination has been missed off one of the
t a PC.
rd is set to invalid number
i.e. 0 or F. other
Instation; only one Instation will operate correctly.
IMD Interrupt Vector switch DS2 incorrectly set.
No UTC TCC
communication with
Instation, SIP VAX LED off
PC not powered up - Check PC power LED on PSU
PCB.
Transformer Select Switch
a) On board transformers required but off board set in error.
No C trol signal on the line and therefore no received signal. The yellow
be on and the green LED off.
b) Off board transformers required but on board set in error.
The power output of the control message on the line will be reduced.
Effect of Incorrect Switch Settings on the
S1, S2, S3 and S4:
If
If the switch is left switched off when there is no OTU on that line, this may a
the integrity of the control signal to other OTUs connected to the same modem
S1 - PCB Address
If
board will be set identically.
2.4.6 Fault Finding at the Instation
Symptom Possible Reason
No UTC TCC Incorrect installa
communications with
Instation, SIP VAX LED on. faulty Ethernet card. On the 3Com Ethernet card,
failure to disable the memory can cause this fai
No
Ethernet T-pieces, either at the UTC TCC or a
PC address on PSU boa
PC address on PSU PCB is set duplicated in an
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