BASIC APPLICATION GUIDELINES & PROGRAMMING
_________________________________________________________________________________________________________
5-17
SIG-00-22-02 JUNE 2022 (Revised September 2022)
Version: B.1
WARNING
THE OOS INPUTS MUST NOT BE LEFT ENERGIZED, THEY SHOULD
BE SET BACK TO THE DE-ENERGIZED STATE.
5.2.6.2 Returning an OOS Function to Service
To return an OOS module or component to service, either select the ‘Put PSO x (RX1, RX2, or
ISL) Back in Service’ option or de-energize the input.
WARNING
THE OOS INPUTS MUST NOT BE LEFT ENERGIZED, THEY SHOULD
BE SET BACK TO THE DE-ENERGIZED STATE.
5.2.7 Wrap Circuits
NOTE
To facilitate in-service testing of WRAP logic, designers should consider
using an input to de-energize the AND “N” Wrap that is being wrapped.
This programming option allows a PSO module’s function to be bypassed by the use of a “wrap
circuit”. The wrap circuit provides the train detection for a track circuit, or combination of track
circuits, which generally extend to or beyond the limits of a GCE approach. Front contacts of
these track relays energize a physical wrap input when the wrap circuits are not occupied.
5.2.8 Wrapped PSO module Operation
PSO modules, while wrapped, do not activate the crossing. A PSO module becomes wrapped
as soon as its physical wrap input is energized by track circuit relay contacts. A PSO module
becomes unwrapped by de-energizing the wrap input when a train is present in any part of the
PSO module approach. Each PSO module can be individually wrapped by the user. Wrap track
circuits may be signal track circuits or modulated audio overlay circuits such as PSO. Each PSO
module wrap has a programmable loss of shunt timer provided. Wrap Pickup Delay time default
is 5 seconds (recommended minimum time).
WARNING
INCORRECT DESIGN AND/OR CONFIGURATION OF WRAP
CIRCUITS MAY RESULT IN LATE OR NO ACTIVATION OF THE
CROSSING WARNING DEVICES.
