Page 514 - IRSEM_Main Book

(c) Interface between external data logging equipment and Electronic
Interlocking system shall conform to approved specification.

(d) Electronic Interlocking System shall be capable of being controlled and
monitored from a either centralized location or distributed locations as per
requirement at site.

(e) It shall be possible to network the Electronic Interlocking Systems for
diagnostic function to a centralized location.

(f) Electronic Interlocking system may be capable of being networked with
other systems for the purpose of centralized control and monitoring.

21.4.4 Interlocking & Circuit Requirements

(a) Interlocking application logic (site specific data) requirements for the E.I
system shall be as per interlocking principles stipulated for Relay
Interlocking and Standard Circuits for Electronic Interlocking.

(b) It shall be possible to modify application logic for yard remodeling or
change in interlocking using approved type of user interface.

(Note: For Standardised Typical Circuits of Electronic Interlocking, may refer to
http://10.100.2.19/signal/policy/uniform_circuit_diagram/Report%20SS%20155
%202019%20(std%20ckts%20of%20EI)%20Booklet%20print.pdf)

21.4.5 Powering up of Electronic Interlocking

(a) Electronic Interlocking system shall drive all the relevant signals to the
most restrictive aspects whenever internal failure of any nature arises or
when Electronic Interlocking system is powered up or during shutdown.

(b) After powering up of Electronic Interlocking the system shall block all
signals and other operations. After verification of safety functions by
Electronic Interlocking system, this blocking shall be released after a delay
of at least 120 seconds.

21.4.6 Configuration of Electronic Interlocking

a) Electronic Interlocking system shall have hot-standby arrangement and
changeover from one system to other systems shall not interrupt status of
signalling.

b) Electronic Interlocking system shall be of either Centralised or Distributed
type as per approved specification and as per policy directives.

c) In case of Distributed configurations, redundancy with route diversity in
OFC communication media and power supply system shall be provided for
linking the subsystems.

d) Electronic Interlocking system in any configuration shall have time
synchronisation.

Chapter 21: Relay & Electronic Interlocking Page 457 of 535