INTRODUCTION
1-1
Document No.: SIG-00-11-10 Version: A.1
SECTION 1
INTRODUCTION
1
INTRODUCTION
1.1
General
The WIU (Wayside Interface Unit) current sensor is a component of the VIU and
iVIU product lines. The WIU current sensor monitors signal lamp current to report if
the lamp is off, on, or flashing. In PTC applications the current sensor monitors the
energized state of the wayside signal lamps, and the signal aspect information is
transmitted by the WIU to the locomotive.
1.1.1
Current Sensor Board
The current sensor board is designed to monitor up to three lamps. The main board
contains all the circuit components needed to create the digital outputs that
represent the state of the lamps, including the sensors themselves. A Current
Sensor Adapter board may be used to interface the lamp circuit to the current
sensor board. Figure 1-1 displays the current sensor module.
Figure 1-1 Current Sensor Module