B
DTRen-2008/SPA-5/LVA
Rev.:
a
Page 16
Bombardier Transportation (ZWUS) Polska Sp. z o.o.
24V DC voltage part
Low voltage part is responsible for the constant batteries’ charging and for the
power supply distribution for all the devices of ERR-2. Batteries (24V DC) are main
power supply of the whole LX equipment (modules on the racks and external
devices).
Voltage from transformers (about 29V AC) is to be rectified and stabilized. EMF-65
suppliers ZsA and ZsB are destined to charge the batteries. Information about
performance of ZsA is passed to the PLC A and information about performance of
ZsB is passed to the PLC B. EMK-2 module checks the value of the battery
voltage from which is powered. Output 5 of EMK-2 is used to pass the information
about the voltage level of the battery to PLC. Threshold value is about 21V. Output
7 of EMK-2 controls the coil of StA (StB) contactor (depending on the control
channel). StA (StB) switches-off the load when the battery voltage is too low.
4.3.3 Interface between SPA-5/LVA and interlocking system
Interlocking system is responsible for sending to SPA-5/LVA engagement and
disengagement commands during normal automatic operation. SPA-5/LVA
operation is based on the electronic interface with the interlocking system Ebilock.
Ebilock sends commands to LX and receives back confirmations and simplified
diagnostic messages.
Different variants of the connection between LX and Ebilock can be prepared
depending on the design requirements (distance between LX rack and interlocking
rack, number of LXs connected to the same station, etc.). Generally 3 types of
devices are necessary to realize interface between SPA-5/LVA and Ebilock:
electronic interface EDJ-5, Protocol Converter Unit PCU and modem (e.g. RAD
ASM-20).
PCU (Protocol Converter Unit)
PCU performs a bidirectional conversion of HDLC data streams into Ethernet data
streams used at the main level of the Ebilock communication. HDLC (High Level
Data Link Control) is a bit-oriented synchronous data link layer protocol developed
by the International Organization for Standardization used in transmission between
Ebilock and its object controllers.
EDJ-5 (transmission converter).
EDJ-5 is a bidirectional converter of HDLC data streams (maximally two streams)
required by Ebilock into one RS-232 data stream used by the object controller.
SPA-5/LVA works as an object controller.
Modem (e.g. RAD ASM-20)
Modems are required in case of long distances between elements of the
SPA-5/LVA – Ebilock interface. Modems are connected with four wire cable and
work in full duplex mode. Modem from one side has a digital interface (HDLC or
V.24/RS232) and on the other side diphase modulated signal (EUROCOM Std.
D1) to provide immunity from background noise, eliminate a normal line distortion
and enable efficient transmission and reception of serial data over a twisted pair
cable for assurance long distance transmission. Modems can be placed between
This
training
material
has
been
prepared
only
for
educational
purposes
and
it
isn't
technical
documentation.
