Download American Audio VELOCITY - REV 4-05 Operating instructions

METRO RAIL DESIGN CRITERIA
SECTION 9 / SYSTEMS
Each recorder shall be capable of recording up to 1 week of events. Each recording device
shall provide access to the data through a standard USB interface port.
9.4.4.12
Environmental Requirements
All equipment shall meet the environmental provisions of the AREMA ATCS environmental
specifications and environmental requirements specified in these Contract Documents.
9.4.4.13
Power Supply
All housings shall be equipped with an external socket for the connection of a mobile
generator. Signaling power supplies shall not be used for any purpose other than to power
signaling equipment. In case of failure of the primary power source, backup power supply
shall be provided to ensure safe train operation as follows:
Grade crossings
Vital equipment
Non-vital equipment
Switch machines
9.4.4.14
8 hours minimum
4 hours minimum
4 hours minimum
4 hours minimum at terminal and junction
interlocking
Lightning Protection
Lightning protection shall be provided for all equipment, which could be damaged by
electrical transients.
9.4.4.15
Design Integrity
The system shall be designed and operated in a safe manner. Failure of the system shall
not compromise the safety of train operation, road traffic or pedestrians.
Any circuit directly affecting the safety of train movement shall be considered “vital”. Circuits
performing functions of control, indication, communication, and other tasks, which do not
directly affect the safety of train movement, shall be considered “non-vital”.
All vital components shall be highly reliable, of proven design and have predictable failure
modes, such that no single failure shall create a less restrictive state.
The signal system logic and its components shall be designed to meet the following:
a) All vital components shall be designed so that restrictive (rather than permissive)
actions occur when a component fails.
b) All vital control logic shall be designed such that, if interrupted or de-energized, it
shall cause the controlled function to assume its most restrictive condition.
c) All relays or solid-state equivalents being energized by a vital circuit shall be
vital units. All contacts used within any vital circuit shall be contacts of vital
relays.
d) All errors of hardware and software that may compromise vital data, whether
DE304.09
Metro Baseline
9-73
Revision 4 : 05/09/12
Re-Baseline: 04/29/10