High Speed Flashcards
(10 cards)
What’s are the HS databus specifications?
20Mbits/S data transfer
Max 4096 data words per transaction (128WBx32bits)
Fibre optic front end (FOFE)
Fibre optic cable transmission
Data distribution by reflexive star couplers
What is the architecture for the high speed databus?
Stanag 3910
How does FOFE work?
It changes optical signals into electrical signals and vice versa
What is a reflexive star coupler do?
It’s a 24 port device with a reflective device at one end of the mixing element and 24 fibre optic pigtails at the other connecting to LRI’s.
What are the Stanag 3910 transaction protocols?
BC - RT HS transfer RT - BC HS transfer RT - RT HS transfer Transmit HS status word HS mode command without data HS mode command with data (Rx)
BC- RT’s HS transfer broadcast
RT - RT’s HS transfer broadcast
HS mode command without data
HS mode command with data (Rx)
Explain the breakdown of a HS and word
Sync Remote terminal address Tx/Rx Sub address (always 26) Data word count/mode code (1) Parity
Breakdown a HS data word
Sync HS bus A/bus B HS Tx/Rx HS sub address HS block count (data word) Parity
Explain a HS BC - RT transfer
LS BC sends command word to RT to inform of HS transaction
HS action word follows contiguously containing the info enabling the RT to process the HS data transaction
Message response time gap
RT send status word LS BC
When does the HS message frame work?
The HS message frame works on the HS channel parallel to the transmission of the status word after 24 - 32microS
Explain an RT - RT HS transaction
BC send a command word to Rx RT
Contiguously followed but a HS action word on LS channel
Message response time gap
RT send status word to BC
BC send command word to RT Tx
Contiguously followed by action word
Message response time gap
Tx RT send status word to BC
Parallel to Tx status word HS message frame
