Optical bus extender 1553
Optical bus extender
The OBE 1553 system allows the bi-directional connection between a Remote Terminal Unit and a
MIL-1553B bus by means of an optical fiber link.
TESEO OBE1553 constitutes a fiber optic extension of the 1553B avionic bus. By means of an OBE1553 a
bidirectional connection can be made between a Remote Terminal Unit and a MIL-STD-1553B bus with the
advantage of the electrical isolation and noise immunity provided by the fiber cable. A typical application is
the connection of an avionic equipment to a distant bus.
The system is protocol transparent because the transmission is analog and the received signal is not
regenerated: at each receiving side of the link the signal wave shape is unchanged like also its S/N ratio.
A bus extender is formed of two transceivers, the OBE1553BC on the side of the bus, and the OBE1553RT
on the side of the Remote Terminal Unit.
The transceivers look the same, but are not identical because some electrical differences exist to allow
them to operate in the right way. Each transceiver is a plug-in module for insertion in an unshielded chassis
IMAGE-MF (3 slots) or IMAGE-MF1 (7 slots) containing power supply, ON/OFF switch and associated
indicator. Each transceiver occupies one slot. A redundant bus configuration occupies two slots in each of
the two mainframes. The bifiber cable (200 um, ST connectors) introduces a delay of 10 nsec per meter,
delay to be added to the 500 nsec caused by the transceivers.
Each transceiver makes available on a front panel connector the received signal for monitoring purposes.
For all the specified parameters and their meanings,
reference shall be made to document MIL-STD-1553B.
OBE1553BC and OBE1553RT common characteristics:
Frequency band
10 kHz to 3 MHz
Common mode
20 Vpp, DC to 2 MHz
≤200 mVpp
Zero crossing deviation
≤25 nsec
Output symmetry
±250 mV peak, line to line
Total delay
<2 μsec (110 m optical cable
Monitor output signal ratio 1/100
Optical connector
ST type
Bus connector
three-axial type
3 Slots Mainframe
Monitor connector
BNC type
Opto-electronic interface, Bus Controller side
Operating temperature
0 to +50 °C
Opto-electronic interface, Remote Terminal side
Storage temperature
-20 to +70 °C
bi-fibre optical cable (mmm is the length in metres)
Power supply
230 Vac –50 Hz
7 Slots Mainframe (replaces IMAGE-MF)
Optical feed-through
OBE1553BC specific characteristics:
Input impedance
1 kOhm min, from 75 kHz to 1 MHz
Input voltage
0.86 to 14 Vpp
Output voltage
18 to 27 Vpp (77 Ohm load)
Output noise
≤14 mVrmsnsec
7 Slots Mainframe (replaces IMAGE-MF)
Optical feed-through
OBE1553RT specific characteristics:
Input impedance
77 Ohm ±2% (after the transformer)
Input voltage
18 to 27 Vpp
Output voltage
0.86 to 14Vpp
TESEO SpA - Corso Alexander Fleming, 27 - 10040 DRUENTO (TO) - Italy
Tel. +39.011.9941911 - Fax +39.011.9941900 - e-mail: info@teseo.clemessy.com
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF