參數(shù)資料
型號: MA28139
廠商: Dynex Semiconductor Ltd.
英文描述: OBDH Bus Terminal
中文描述: OBDH客運(yùn)站
文件頁數(shù): 21/34頁
文件大?。?/td> 416K
代理商: MA28139
MA28139
21/34
THE ESA ON-BOARD DATA HANDLING
(OBDH) BUS
The dual redundant OBDH bus is connected to the OBT
bus interface via an input descriminator and an output bridge
driver circuit. These convert between the bipolar LITTON code
and the standard CMOS inputs and outputs of the IC.
The OBDH bus is divided into three parts:
A. INTERROGATION BUS (I BUS)
This bus is used to transfer data from the CT to the
RTs, as commands of 32 bit words, each bit being modulated
according to the Litton scheme shown in Figure 18. Each
Interrogation (or command) “slot” comprises 3 Sync bits, 3 or 4
BroadCast Pulses, 5 or 6 Terminal Address bits, 4 Destination
Address bits, 16 Data bits and a Parity bit.
B. RESPONSE BUS (R BUS)
This bus is used to send data from the RTs to the CT, (can
be used by RTs to receive data). Each response word
comprises the 4 Destination Address bits sent in the
corresponding Interrogation, either 8 or 16 Data bits from the
user (8 bits unless a 16 bit acquisition was requested and 8
zeros if no response data is required) and a single Stop bit
(used to ensure data is fully clocked through bus modems and
0 by convention).
C. BLOCK TRANSFER BUS (BT BUS)
Used to transfer blocks of data between the CT and RTs, in
either direction, as a contiguous block or stream of data bits.
Figure 18: Litton Coded Data
logical
"1"
logical
"0"
invalid
logic
"1"
invalid
logic
"0"
high -
low -
0v -
high -
0v -
high -
low -
0v -
low -
0v -
invalid
logic
"1"
high -
0v -
logical
"1"
invalid
logic
"0"
low -
Synchronisation Pattern
FASTER OBDH/DBI COMPATIBLE NETWORKS
With analog components the OBT can interface any
equipment to the specified ESA OBDH bus at the nominal data
rate of 0.5 Mbps. Contract 5352 proved that analog
components limit OBDH data rate to 2 Mbps maximum. But
OBTs work to over 5 Mbps (10MHz with 2 clocks/bit Litton
coded). OBTs may be directly networked via digital bus
drivers/receivers, (eliminating analog components) using
Litton coded 4 wire (R2/DS1 and R4/DS2) busses (see OBDH
application note 1). MSS made a 3 metre optical OBDH
network for the Pegasus ion source.
DBIs may be directly connected but will not be Litton coded
with Parity on every bit, or exhibit modulation and
demodulation delays.
相關(guān)PDF資料
PDF描述
MA28140 Packet Telecommand Decoder
MA28151 Radiation hard Programmable Communication Interface
MA28155 Radiation Hard Programmable Peripheral Interface
MA31750 High Performance MIL-STD-1750 Microprocessor
MA31751 Memory Management & Block Protection Unit
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MA28140 制造商:DYNEX 制造商全稱:Dynex Semiconductor 功能描述:Packet Telecommand Decoder
MA28150FBB 功能描述:專用陶瓷電容器 HF CHIP RoHS:否 制造商:Panasonic Electronic Components 電容:470 pF 容差:10 % 電壓額定值:250 VAC 工作溫度范圍:- 25 C to + 125 C 端接類型:SMD/SMT 外殼代碼 - in: 外殼代碼 - mm:
MA28150FBN 功能描述:專用陶瓷電容器 HF CHIP RoHS:否 制造商:Panasonic Electronic Components 電容:470 pF 容差:10 % 電壓額定值:250 VAC 工作溫度范圍:- 25 C to + 125 C 端接類型:SMD/SMT 外殼代碼 - in: 外殼代碼 - mm:
MA28150GBB 功能描述:專用陶瓷電容器 HF CHIP RoHS:否 制造商:Panasonic Electronic Components 電容:470 pF 容差:10 % 電壓額定值:250 VAC 工作溫度范圍:- 25 C to + 125 C 端接類型:SMD/SMT 外殼代碼 - in: 外殼代碼 - mm:
MA28150GBN 功能描述:專用陶瓷電容器 HF CHIP RoHS:否 制造商:Panasonic Electronic Components 電容:470 pF 容差:10 % 電壓額定值:250 VAC 工作溫度范圍:- 25 C to + 125 C 端接類型:SMD/SMT 外殼代碼 - in: 外殼代碼 - mm: