Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 11 Page 143 of 265
15.3.27 Transmission Confirm (TC)
The ‘TC’ input is not a transmitted control bit but an output from the OTU to the
controller. Its presence indicates that valid transmission is being received from the
central computer. No control bits are actioned unless ‘TC’ is active. Also see section
15.5.
15.4 Miscellaneous Reply Bits
15.4.1 Controller Fault (CF)
A ‘CF’ reply bit may be returned to indicate that there is an entry in the controller
fault log. If ‘DF’ and ‘LF’ reply bits are also configured, the ‘CF’ reply bit can be
configured to ignore DFM faults and lamp faults.
15.4.2 Detector Fault (DF)
A ‘DF’ reply bit may be returned to indicate that the Detector Fault Monitor has
detected a faulty detector (see section 29.6).
15.4.3 Lamp Fault (LF)
An ‘LF’ reply bit may be returned to indicate that the controller has confirmed one or
more lamp faults (also see section 38).
15.4.4 Manual Control Mode (MC) and Remote Reconnect (RR)
Either an ‘MC’ or ‘RR’ reply bit may be returned to indicate any of the following
conditions:
a) Manual mode operating.
b) Manual mode selected.
c) ‘Normal’ mode select button not selected, i.e. Manual, FT or VA selected.
d) ‘RR’ button pressed on the Manual Panel (if configured).
When ‘MC’ or ‘RR’ is active, the central office the computer releases control. When
‘MC’ or ‘RR’ is no longer active, the computer will regain control without having to be
reset by the operator, unlike ‘G1/G2’ (see section 15.3.2).
Normally ‘MC’ and ‘RR’ are used to request the computer to release control or to
inform it that the controller has adopted a higher priority mode by selection, i.e.
Manual, Fixed Time or Vehicle Actuated.
If Manual mode is a lower priority than UTC mode, ‘RR’ bit is activated when manual
mode is selected and is used to request the computer to release control so that the
controller may be operated manually. When NORMAL is selected on the mode
buttons, ‘RR’ will stop being sent and the computer will automatically regain control.