The Benchmark Optical Fibre Trainer - OFT - is
the base-line for every fibre optic laboratory. It
demonstrates state-of-the-art concepts in fibre optic communications.
It provides for easy experimentation and effectively
bridges the gap between a leading-edge technology and currently available
technical training tools. As the concepts demonstrated are no different
from those encountered in real-life systems, it can provide significant
insights, of direct relevance, to the student and practicing engineers
alike. In addition, it can serve as a ready-made communications platform
for photo typing and in applications calling for fibre optic capabilities.
Features
- Eleven usable 64 kbps channels
- User definable frame marker (two alternating 8-bit markers - can be set to CCITT compatible)
- On-board two digitised voice channels, one 8-bit data channel and several
user-expansion channels
- Demonstrates fully operational integrated voice/data fibre-optic communication
link
- RS - 232C communications module optional - demonstrates computer communications
over fibre
- Time Division Multiplexing of voice, data & user-defined data streams
- Modular design enables configuration with user-defined modules
- Wide scope for experimentation through use of external circuitry interfaced to kit
- Comprehensive manual describes wide range of experiments - can form basis of courses
- Ready -to -use kit comes complete with accessories
Description
- 850nm and 650nm fibre links
- Demonstrates established digital communication techniques such as:
- - Time Division Multiplexing, Transmitter & Receiver operation
- - PCM voice coding (at 64 Kbits/sec)
- - Manchester coding/decoding for timing recovery, etc.
- Channels switchable at transmitter & receiver using time-switching principles
- Easy interface to external circuitry - all required inputs and outputs provided and extensively documented
- Power available to external circuitry as well
- Comprehensive laboratory manual
- - clearly explains the theory of fibre optic analog and digital communications through in-depth experiments
- Accessories
- - all accessories required to conduct basic experiments and to interface to external circuitry are provided in the kit
- Options
- - RS-232C communication interface module available as option
to enable computers to be connected over fibre - demonstrates integrated voice/data/RS-232
communication link
Experiments
Basic Experiments
Can be done using just the standard kit
- Fibre optic experiments
- - Fibre optic analog links
- - Digital links
- - Losses in optical fibre
- - Effect of EMI interference
- - Numerical aperture measurement
- Multiplexing and digital communication experiments
- - Time division multiplexing
- - Framing in time division multiplexing
- - Manchester coding/decoding - timing recovery
- - Voice coding - A-Law
- - Pulse broadening in fibre optic communications
Advanced Experiments
Concepts explained in manual, requires circuit development by user
- Interfacing 8kbps synchronous channels
- Interfacing 64 kbps synchronous channels
- Interfacing 256 kbps synchronous channels
- Interfacing synchronous channels at less than 8 kbps
- Asynchronous channel interfacing using over sampling
- Asynchronous channel interfacing using stuffing
Advanced Applications
Concepts explained in manual, requires circuit development by user.
- 1/4 voice channel
- Manchester coder/decoder with PLL clock recovery
- 4B/5B (or5B/6B) coder/decoder with clock recovery
- Frame marker coder/decoder
- RS-232 communication link
- Slow-scan video link
Specifications
 |
Electrical |
|
|
|
|
Number of channels |
|
12 (64 Kbits/sec) channels, including one slot for 16 bit
marker |
|
| |
Frame marker |
|
Two 8 bit markers in alternate frames, user settable, can
also be set to CCITT standard |
|
| |
Coding/decoding |
|
Manchester coding/decoding |
|
| |
Data Rate |
|
768 Kbits/sec, 1.536 Mbits/sec after Manchester coding |
|
| |
Voice PCM channels |
|
Two. (Two telephone handsets provided) |
|
| |
Voice coding |
|
A-Law |
|
| |
Analog input voltage |
|
1V(pp) |
|
| |
Analog input bandwidth |
|
100 KHz |
|
| |
|
|
|
|
| |
Optical |
|
|
|
| |
Wavelengths |
|
650nm and 850nm |
|
| |
FWHM spectral width |
|
100nm |
|
| |
Fibre |
|
1000 micron plastic fibre (1m, 3m and 20m lengths
included) |
|
| |
Max link length |
|
30m for 650nm optical digital link |
|
| |
|
|
5m for 850nm link |
|
| |
Max data rate |
|
2 Mbits/sec (NRZ) |
|
|
|
|
|
|
Top of Page
Ordering Information
|
Description |
|
Part # |
|
|
Optical Fibre and Digital Communication
Trainer |
|
OFT |
|
| |
RS-232C Interface Module for OFT |
|
OFT RS-232C |
|
| |
20m (650nm) link option for OFT |
|
OFT-LINK-20 |
|
|
|
|
|
|
