1553 news
The MIL-STD-1553, which means Standard Military, is as his name indicates it, a standard military officer, that was developed by the American army for the military airplane F-16 in 1973. A second version called MIL-STD-1553B was developed in 1978 and is used for all the avionic systems military officers. It is this second version that proposed you in our products. It is a bus series asynchronous that allows the communications bi-directions on a simple bus. Connected them final are not autonomous, they are managed by a bus inspector. MIL-STD-1553B defines three types of stations: a bus inspector (Bus Controller, BC), the final from afar (Final Remote, RT) and the bus supervisors (Bus Monitor, BM) csma/ca
Physical support: The bus MIL-STD-1553B uses a structure Order/Response. This bus series is asynchronous and the messages are multiplexés between the users. The bus inspector checks the flows for all the data that circulate on the bus. It is the only machine that can initialize the communications on the bus. The final one from afar uses interface between the under system and the bus 1553, transferring the data to the and outside the under system under the check of the inspector of bus. The bus supervisor assures only the function of listen for the applications. This bus of data series uses the encodage Manchester 2 Doublets. The receivers decode the signal while using the clock of the signal to extract the bits of the word. The transmission of the data is done on two armored twisted pairs (to protect itself from the exterior parasites). And the rate of transmission of the words is of 1MBPS.
Level Liaison: The words are transmitted to 1MBPS on of the weave of 20 bits: 16 bits of data, 1 bit of parity and 3 bits of sync. MIL-STD-1553 uses the technique of the polling as check system. A single knot checks the access to the canal and the other knots sequentially are questioned for knowledge if they have messages to send. If a station has a, she transmits it, then the bus inspector continues to question all the stations. It exists two types of formats of messages: the format of transfer of information (non-broadcast) and the format of transfer of broadcasting of information (broadcast). A message does not exceed 32 words. The report signal/noise is satisfactory in almost all the applications. A final one from afar can have an error after 52 millions of received words. That is to say about an error all the 33 minutes for messages inspector of final bus from afar of 10 words to a rate of 1667 messages per second. The messages of 10 words to this rate correspond almost to the half of the capacity of the bus. If the system uses messages non-broadcast, or verifies the broadcast by a method order, the system will detect an error all the 33 minutes and will activate the system of correction of errors to resolve it. The probability for that an error is not detected is of 1 bit on 10E21 bits transmitted.
That surpasses the length of life of the application before an error is not detected. It is to be noted that if a liaison breaks itself or if the bus inspector breaks down, it is the whole network that falls. This is the reason why, to avoid that, MIL-STD-1553B uses redundant buses and one or ready inspectors of bus to take the relay in case of breakdown. The MIL-STD-1553B detects the faults, it uses also the double redundance of bus and of inspector of bus and it is tolerant to the faults. It is therefore his reliability that did him the standard military officer. MIL-STD-1553B uses the Polling as refereeing protocol. The polling being deterministic, MIL-STD-1553B it east also. The MIL-STD-1553B admits several transmitting ones by bus therefore, the weight of the sons considerably is reduced in comparison with the ARINC 429.