Tactical Controls Limited
Distance Trip Meter
Instruction Manual
4.
When count down reaches zero, release and remove key.
5.
Observes that the Highest speed attained shows current speed or zero, whichever
is higher.
6.
Release the buttons, the display should go blank.
Acceleration/deceleration test
To display the average acceleration or deceleration in m/s/s (meters per second per second),
press all three push buttons simultaneously. The display will show "dDDxxAA" where "d" is
the symbol for maximum Deceleration, "DD" is the maximum deceleration attained so far
during the test, "xx" could be "Ac" or "dE" depends on whether the train is in acceleration or
deceleration on average so far during the test, "AA" is the average acceleration or
deceleration. The acceleration or deceleration has a range from 0.0 m/s/s to 6 m/s/s.
To cancel the acceleration test, press all three push buttons again simultaneously. Any other
combinations of push buttons pressed are ignored when the DTM is in acceleration test mode.
There is also a time out period of 2 minutes, after which the acceleration test mode is
cancelled and the display goes blank.
Please note that unlike the 3 distance parameters and the highest speed, the maximum
deceleration attained during the test is not recorded. The acceleration/deceleration test always
starts with the maximum deceleration set to zero.
Please also note that the average acceleration/deceleration shown are calculated by subtracting
the initial speed at the start of the test from the current speed and divided the result by the time
elapsed from the start of the test. Hence the changes of the average acceleration/deceleration
will become less and less as the test progresses.
Data retention
The DTM stores the 3 distance parameters and the highest speed attained in non-volatile
memory. In the event of power failure, these data are protected and recalled from the non-
volatile memory when the power is returned.
The DTM is designed to ensure that the data retention capability of the unit has good RFI
immunity. The use of a single-chip microcontroller with special built-in EEPROM offer high
reliability for parameter storage. Also the unit's metal enclosure is designed to provide good
RFI shield.
Power supply
The DTM is powered by the Train's control supply which is nominally -50Vdc with the
positive pole earthed. The design can accommodate a ripple of up to 5V peak to peak, at a
nominal frequency of 850Hz and associated harmonics. DTM's supply input is designed to
withstand the RIA12 Surge and Transient tests.
Installation
IM
Page 6
21 March 2003
Issue 2.0
