General description
Functional
The 21-219, Fiberoptic IEEE C37.94 - G.703 E1 converter is intended to extend
distance and galvanic isolate the teleprotection equipment for substations connection
to telecom network.
IEEE C37.94
The standard “IEEE C37.94-2002, IEEE Standard for N times 64 Kilobit per
Second Optical Fiber Interfaces between Teleprotection and Multiplexer Equipment”
describes a fiberoptic intra-substation communication links between teleprotection
equipment and multiplexers.
125µs
250µs
375µs
500µs
(256 bit frame)
0
h
g
f
e
d
c
b
0 0 0 1
a
1
1
1
( 16 bits )
Header (sync)
1
/s
s
/r
r
/q
q
/p
0 1 0 1
p
0
1
0
( 48 bits )
Overhead
0
1
……...
D1
( 192 bits )
Channel Data (payload)
……...
/D1
D2
/D2
D3
/D3
D4
/D4
D96 /D96
The bit c in “Header” is used for “Yellow Alarm”. (Every other frame).
Bits p,q,r and s in “Overhead” form a HEX-value indicating the number of timeslots
used for data.
0.0.0.1 for N=1
0.0.1.0 for N=2
….
1.1.0.0 for N=12 , (0CH).
12 timeslots, (1 timeslot has 8bits
Î
12x8bits=96bits. With complement bits
Î
2x96=192 bits). Data bits in not used timeslots are set to 1.
4
