6F2S1916 (0.
5
)
GIF200
- 2 -
2
Settings and operations
Figure 2.1-1 shows the outline of the GIF200 unit. Two optical modules (E/O and O/E with ST
port) for the IEEE C37.94 and a CN1 (D-sub 25-pin or DB-25) socket for the ITU-T G.703 are
provided; the TB1 terminal is provided for the DC power input.
Overview
The O/E and E/O conversion is performed on both transmit and receive signals from the
GRL200 IED respectively. The optical signals are encoded in CMI type (50% duty factor) and
it makes the signals easy to be checked during commissioning. Code conversion is performed
for connection to the ITU-T G.703, which is a synchronous interface and provides a 64 kHz
timing signal, which the GIF200 uses for synchronization†.
†Note: When GIF200 unit has lost clock signals coming from MUX, GIF200 unit can send
signals to MUX using GIF200 internal clock signal. This self-running is only
applicable when GIF200 unit is produced in the ITU-T G.703/contra-directional.
GIF200 unit
GI fiber optic cable
(50/125 or 62.5/125μm)
DC24 to 220V
N
P
FG
DC5V
FG
FG
FG
G
P
TB1/Power
RX
TX
ST port
C37.94 signal
E/O
O/E
Code
conversion
TX
Ta
Tb
CLK†
Ra
Rb
RX
Code
conversion
25
24
21
20
23
22
CN1/G703
Twist cable
G.703 signals
From/to MUX
From/to GRL200 IED
Figure 2.1-1 Block diagram in the GIF200
Table 2.1-1 CLK comparison table in ITU-T G.703
CLK signal
Co-directional
Centralized clock
Contra-directional
Transmitter in
G.703
No CLK connection
required with MUX
CLK to be connected with MUX for generate the TX
‡Note:Either “Co-directional (Code=1)” or “Centralized clock/Contra-directional (Code=2)”
is specified by the selection in GIF200 ordering code.
Connection in C37.94 at ST connectors
As shown in Figure 2.1-1, the type of connector for fiber optic (GI type) cable in C37.94 from/to
the GRL200 IED is ST. Note handling with fiber optic cables not to be damaged by rough
