UTMC OTU/MOVA Handbook
667/HB/31601/000
Page 106
Issue 5
7.7.5 MO: MOVA Override Control Bit
Condition '1' will enable MOVA to send force bits to the traffic controller in place of the
UTC control bits.
Condition '0' will select normal UTC operation i.e. all the UTC control bits will be sent to
the traffic controller.
If MOVA is not available then UTC will remain in control.
7.7.6 MR: MOVA Override Reply Bit
Condition ‘1’ confirms that the MO bit is being actioned by the outstation.
Condition '1' can also mean that MOVA has been told to override UTC
control by a local source.
NB: There may be local conditions which mean that although MO is active
and MR has been returned, MOVA is not actually controlling the
controller e.g. MOVA many not have been configured, MOVA is in
its warm-up cycles or MOVA is off-line.
The ML bit will confirm that MOVA is in the on or off-line condition.
7.7.7 ML: MOVA Online Reply Bit
Condition ‘1’ means that MOVA is on-line and controlling the traffic controller.
If MOVA is not available, this value is set to '0'.
7.7.8 MF: MOVA Fault Reply Bit
Condition ‘1’ means that MOVA has detected a fault, this is equivalent to the MOVA
Phone-Home condition.
The MOVA unit will report this fault when the MOVA error count has exceeded the fault
threshold, which is 20 by default.
7.7.9 Switching From UTC to MOVA
While UTC is controlling the junction, the UTC TC bit is active and the F-bits are driven
by UTC. Then when UTC sets the MO bit, this enables MOVA to take control, provided
that the controller is setting MOVACRB active. The sequence is:-
MO activated from UTC
MOVA activates MR reply bit to UTC
MOVACRB returned as active (provided that the controller is ready to accept
MOVA control i.e. lamps on and no higher priority mode active)
MOVA waits for next stage change
MOVA activates MOVATO and appropriate F-bit to the controller
