The mbs’ ÆSyBus product range provides Full Duplex Gigabit Ethernet/IP interfacing to various Avionics and Industrial data buses and a separate document provides more detail on the ÆSyBus concept and how its unique architecture can be exploited to provide a cost effective, distributed interface and processing system with outstanding performance. Many new products are planned to expand this flexible, easy to program family.
 

Inter-Module Message Communication

The ÆSyBus-1553-R can be configured to automatically send and receive Ethernet frames with MIL-STD 1553 Commands and Data. It supports both basic Ethernet and UDP/IP communication protocols with complete freedom to select the various source and destination addresses, including broadcasting of messages.
 

When operational, the Inter-Module Messaging facility will automatically construct frames with received MIL-STD 1553 Commands, Status and Data and send them out over the Ethernet Data Bus. On reception of such Ethernet frames, the Data is automatically transferred to locations in the Transmit Data buffer from where it can be automatically retransmitted when required. If the Terminal is configured as a Bus Controller, then the Ethernet data will be suitably processed so that the message is automatically repeated on the local MIL-STD1553 data bus.
 

If the Terminal is configured as a Remote Terminal, then the data is transferred to the appropriate locations where it can be automatically retrieved when commanded by the Bus Controller.
 

Under the normal default configuration, the ÆSyBus-1553-R will power-up with Inter-Module messaging disabled and it is left to the user to configure the facility and enable operation via a register before communication will commence. However, configuration data can be stored in EEPROM so that the ÆSyBus-1553-R can automatically configure itself and become active immediately following power-up.
 

MIL-STD 1553 Operation

The ÆSyBus-1553-R can be configured either as a Bus Controller, Remote Terminal or Bus Monitor with or without assigned RT Address. 
 

When operating as a Bus Controller, the user has full control over Bus Selection, Periodic and Asynchronous communication. A Transmit Scheduler provides the user with a simple means for regimenting Periodic Communications with full control over main and sub-frame messages. Asynchronous and periodic transmissions mix naturally onto the bus with periodic transmissions taking priority. 
 

Data for transmission is drawn from user defined locations in the Transmit Data Buffer. Data received from Remote Terminals is automatically transferred to locations in the Receive Data Buffer, which is organized as a cyclic buffer with a capacity for 256 data words. The Write Pointer to this buffer is stored with Time Stamp and other status information in the Message Status memory. This memory is also organized as a cyclic buffer, the contents of which can be automatically transferred with the Receive Data buffer etc. periodically to any host application. By using cyclic buffers, multiple host applications can read the Receive and Status Buffers without data loss.
 

Software

The choice of Ethernet with UDP/IP protocol provides the user with a distributed, platform independent interface. Practically all computers support Ethernet and all operating systems and development tools support Internet Protocol. In addition, the ÆSyBus-1553-R comes with full documentation, an API and many software examples in source code.
 

Inter-module Messaging Features

• Support for basic Ethernet and UDP/IP Communication

• Fully configurable autonomous operation

• Automatic capture, transfer and retransmission of MIL-STD 1553 messages

• Automatic non-volatile configuration feature for standalone operation
   

General Features

• Full Duplex Gigabit and 100BaseTx Ethernet

• 10 UDP user assigned ports

• Onboard system Timer with support for external synchronization

• Time Stamping of MIL-STD 1553 communications

• User configurable, host message scheduling

• Full status monitoring

• Automatic capture of all receive data and status

• Fully compliant MIL-STD1553B message processor
   

BC Features

• Configurable Transmit Command Scheduler

• System Command FIFO for asynchronous control
   

RT Function

• Automatic dual redundant bus switching
   

MT Features

• Configurable single or multiple monitoring modes