Fibersystem 21-219 Technical Manual

Fiberoptic IEEE C37.94 - G.703 E1 mux

21-219

Technical manual

Technical Manual 90_20_0113R0

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About this manual

About the contents of this manual

The information in this document may be changed at any time without notice.

T able of Contents

About the contents of this manual 2
Table of Contents 2
Version and revision history. 3
Revision history for product: 3
Revision history for this document. 3
Functional 4
IEEE C37.94 4
G.703 E1 2048kbit/s 5
Applications 6
Features 8
Fiberoptic and data transfer protocol 8
G.703 – E1 8
Power Supply. 8
Environmental conditions 8
CE compliance 8
Mechanical 8
EMC compliance 8
Insulation 9
Physical size and Weight 9
Unpacking. 10

Product 21-219 consists of: 10
Serial number. 11
Front Panel. 11
Back Panel. 11
BNC 75 Ohm G.703 E1 Port 12
Fiber Optic IEEE C37.94 Ports. 13
Functional earth/ground, FE. 13
Normal use 14
Config rotary switch 14
External clock 15
Internal clock – “Master mode” 15
Power on. 16
LED-status. 16
CE - mark 18

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V ersion and revision history .

Revision history for product:

Revision R0.

Product released for serial production. 2006-05-26.

Revision history for this document.

Revision AK0.

2006-05-30, AnNy, document created.

Revision R0.

2006-06-05, AnNy, document released.

Document properties.

Last saved: 6/5/2006 3:42:00 PM
Filename: Technical Manual 90_20_0113R0

Author.

Created by Anders Nyström.
Last saved by Anders Nyström.

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)

0hgfedcb 0 0 0 1a 111

( 16 bits )

Header (sync)

1/ss/rr/qq/p 0 1 0 1p 010

( 48 bits )

Overhead

01

……...

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.

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G.703 E1 2048kbit/s

The G.703, E1, 2048kbit/s unbalanced, (75 Ohm BNC), ports are intended to
connect to, for example, a leased telecom line.

21-219

There are two C37.94 fiber optic ports that are multiplexed into one E1-protocol.
“Channel 0” is inserted/extracted in timeslot 1 – 13 in the E1-protocol.
“Channel 1” is inserted/extracted in timeslot 17 – 29 in the E1-protocol.
E1 timeslot 0 contains framing/synchronization information. Timeslots 14, 15, 16, 30
and 31 are ignored at receive and set to 0 at transmit.

In the IEEE C37.94 protocol each data bit is followed by its complement. Only
“true”, (non complement), data bits are transferred to E1-protocol.

The N is fetched from the IEEE C97.94 protocol indicating the number of timeslots
used in the protocol.
The 21-219 transfer the N-value but don’t use it for any other purpose.
All data bits in all 12 timeslots are transferred, regardless of the value of N.

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Applications

Singel IEEE C37.94 link via Telecom network.

Dual IEEE C37.94 link via Telecom network.

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