Introduction; Application - Toshiba G1IF1 Instruction Manual

1. Introduction

The Optical interface unit G1IF1 facilitates connection of the fibre optic protection signalling
channel of the GRL100 line differential relay to remote multiplexing equipment associated with
a switched telecommunications network. This manual should be used in conjunction with the
manual for the GRL100 relay.

2. Application

The Optical interface unit G1IF1 provides a connection between a fibre optic communications
channel and a switched telecommunications network. It is applied in the protection signalling
channel of the GRL100 line differential relay, allowing two GRL100 relays to communicate over
a telecommunications channel.
The G1IF1 provides an interface for connection of the fibre optic protection signalling port of the
GRL100 relay to remote multiplexing equipment having a standard CCITT G703 or X.21 type
interface to the electrical connections of a telecommunications system. Figure 2.1 illustrates the
application of the G1IF1 unit.
In most situations the telecommunications equipment is remote from the protection equipment in
the substation. The G1IF1 unit is normally located close to the multiplexer and may be up to 2km
away from the GRL100 relay. The fibre optic cable must be either 50/125m (for distances up to
1km) or 62.5/125m (for distances up to 2km) and should be terminated with standard ST type
connectors.
The G1IF1 is connected to the switched telecommunications network via a multiplexer. The
interface is defined according to the CCITT G703 or X.21 standard. The connections should be
made using shielded, twisted pair cable.
Model Telecommunication
X.21
G1IF1-01
CCITT-G703-1.2.1
G1IF1-02
G1IF1-03 CCITT-G703-1.2.2 or -1.2.3
G1IF1-04 X.21
(*): If the outer case is required, it is ordered separately as option. See Appendix C.
GRL100
Line
Diff.
Relay
Fibre
Optic
Cable
Figure 2.1 Application of G1IF1 Unit
Table 1 G1IF1 Models
G1IF1
CCITT G703
or X.21
Interface
 4 
6 F 2 S 0 7 5 5
Outer case
With outer case
Option(*)
Option(*)
Option(*)
Switched
Telecomms
Muliplexer