Electro-optical data bus

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference should now be made to FIG.
1 of the drawings which is a schematic block diagram which shows a presently preferred embodiment of a hybrid multiplex data bus system constructed in accordance with the present invention.
In the drawing, the electrical bus portion of the system is enclosed within a first dashed boundary (100) while the optical bus portion is enclosed within a second dashed boundary (200).
Electrical portion (100) is relatively conventional and is preferably constructed in accordance with the aforementioned Military Standard 1553B.
In accordance with certain options contemplated by (but not required by) said Standard, electrical data bus (100) is quadruply redundant and in fact incorporates four separate two-way data links.
The first two collectively form the A bus (12) which in turn comprises a primary A bus (14) and a secondary A bus (16).
In similar manner, there is also provided a B bus (18) comprising a primary B bus data link (20) and a secondary B bus data link (22).
Associated with the A.
sub.
1 bus (12) is a pair of terminals, namely, the A terminal (24) and the A.
sub.
2 terminal (26).
Also connected to the A bus (12) is the A bus controller (28).
As shown in the drawing, the A bus controller (28) is also associated with a backup B bus controller (30) which is connected to the B bus (18).
Thus, the A bus controller (28) and the backup B bus controller (30) can communicate with one another directly without resorting to the use of the A bus (12), in the event that a serious malfunction condition is detected on the A bus (12) and/or with its associated A bus controller (28).
The functions that normally would have been allocated to the A bus (12) may then be performed by the B bus (18) under the direction of the backup B bus controller (30).
Alternatively, if the fault is such that only the A bus controller (28) is affected, then the backup B bus controller (30) may function as a terminal connected to the B bus (18) so as to transmit an appropriate message to the B bus controller (32) via the B bus (18) which it will be noted is directly connected to the backup A bus controller (34), so that the backup A bus controller (34) may take over the critical functions of the inoperative A bus controller (28)