Siemens TC12 Installation, Commissioning And Maintenance Handbook page 159

IOR
MTS
SCM/SRM
CNL1/CNL2
CMSL / RMSL
RSE
RTE
INDICATORS
IDLE
TX and CD
RX Errors
4.5.3.2 Faults and their Indications
Below is a list of common faults and the possible indications with regard to the
faults likely to be logged.
WHILST CHECKING AT INSTATION:
666/HE/43100/000
TC12 Installation, Commissioning & Maintenance Handbook
Address of OTU in message received whilst expecting reply from
OTU under test, was not address of OTU under test.
MT bit set in reply message received from OTU under test.
Short Control / Reply Message, i.e. insufficient bytes received.
Port1 / Port2 Carrier not low when expected.
The Instation Test Set uses two comms ports to communicate
with the system, it uses comms port 1 for all CONTROL
communications,
communications.
The ITS uses timings such that it starts checking for the start of a
particular message during what should be the inter message gap
prior to that message. Thus if when it starts checking for the
message the carrier is still present and after a further short delay
(see note below) it is still present, then it is adjudged to have
missed the inter-message gap and indicates this error.
NB 5 ms are allowed from start of checking before this error is
flagged, in case it is simply a slight timing error which will then be
flagged by the message started late error.
Control / Reply message started late. After the point at which the
message should have started, the ITS opens a window (as does
the Instation) during which it expects to receive the first byte of
the message. If it does not receive the first byte the message is
indicated as having started late.
Spare bit in reply message was in wrong state. Should always be
0
Type bits in reply message were in wrong state. They should
always be zero for reply.
Indicator which will come up against each port if no data has been
received for at least two consecutive seconds. Appears at left hand
side of screen. (NB This is hidden by fault log when fault log is being
displayed).
These two displays give an indication that communications are
occurring.
This field generally indicates the last fault to be registered in the fault
log. However one fault "Not Yet Synchronised" (which is displayed if
data is being received but none of the data appears to be control data
i.e. none of first characters in messages received are sync byte), may
be displayed but there is no log for these.
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and comms port 2 for all REPLY
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