
INTRODUCTION
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1-1
SIG-00-07-11 SEPTEMBER 2012 (REVISED OCTOBER 2019)
Version No.: B.2
SECTION 1
INTRODUCTION
1.0
INTRODUCTION
1.1
GENERAL
This document describes the installation, configuration
and operation of the Siemens Vital Interface Unit (VIU),
part number A80515.
The VIU is a general purpose programmable logic
controller that can monitor the state of its inputs, perform
logic functions and generate vital communications
messages to report its status or the status of devices
connected to its inputs.
Each VIU unit has the ability to monitor up to twenty (20)
vital inputs. If additional vital I/O is required, multiple VIU
Units can be cascaded. Each VIU provides event
recording capability.
The VIU supports the standard Positive Train Control
(PTC) protocols and Wayside Interface Unit functionality
as defined by the Interoperable Train Control (ITC)
Committee. The VIU utilizes the Interoperable Train
Control Messaging (ITCM) and the vital Advanced Train
Control System (ATCS) communication systems to generate Wayside Status Messages that are
passed to the office and to trains.
WARNING
THE VIU IS CAPABLE OF BROADCASTING VITAL EMP
STATUS MESSAGES. THE USE OF THE VIU IN A LARGER
SYSTEM WITH OTHER COMPONENTS SHOULD BE
CONSIDERED CAREFULLY SO AS NOT TO INADVERTENTLY
COMPROMISE THE VITALITY OF THE EMP PROTOCOL.
The ATCS protocol also supports remote configuration and control of selected VIU operational
parameters.
1.2
APPLICATIONS
Application specific functions performed by the VIU are controlled by a Module Configuration
File (MCF). The MCF is programmed using the Siemens Geographic Configuration Suite (GCS).
The MCF currently supplied with the VIU supports two applications: the Wayside Interface
Application and the Office Monitoring Application. These applications are described briefly in the
following paragraphs. Expanded descriptions are provided as indicated in later sections of this
document.