OmniBus® Family for Serial

Description

Ballard's OmniBus products connect computers or networks to one or more avionics databuses or other interfaces. OmniBus Serial refers to RS-422, RS-232, and RS-423 serial capabilities available for all modular OmniBus platforms. Separate web pages provide information on OmniBus platforms (PCI, cPCI, PMC, VME, USB/Ethernet), avionics protocols (MIL-STD-1553, ARINC 429, ARINC 708, ARINC 717, and CSDB), and discrete IO.

OmniBus products are built around an intelligent platform that can host one or more protocol modules. This flexible architecture accommodates mixed protocols, high channel counts, and unsurpassed processing power. An on-board PowerPC® processor can be programmed by the user to offload the host or for stand-alone operation. Each module has its own DSP dedicated to protocol processing.

OmniBus Serial products are used to interface with equipment using RS-422, RS-232, and RS-423 asynchronous communications. OmniBus Serial modules have four independent universal asynchronous receiver transmitters (UARTs), each having one transmitter and one receiver. A combination of software programming and connection wiring configures each port for balanced RS-422 or for unbalanced RS-232 or RS-423. User software controls the baud rate, word encoding, and other parameters. Each transmitter and receiver has a large 4 Kbyte FIFO with a programmable threshold for event triggering. Software can interact with the interface through polling or interrupts.

ARINC 429 channels may be combined with OmniBus Serial ports on the same module. Applications for OmniBus products include testing, simulation, and operational uses of avionics databuses. The high channel count, multi-terminal capability, and on-board PowerPC processor provide the power necessary for flight simulators and system integration laboratories. An OmniBus product may also be used as a data server or as a stand-alone converter from one protocol to another.

Serial Functional Specifications

Ports (UARTs): 4 per module

• (4 transmitters and 4 receivers per module)
• Hardware flow control (RTS, CTS, etc.): Not implemented

• RS-422, RS-232, or RS-423 per port
• Select through software and connector wiring

• To over 1 Mbps
• By formula from CLK1 or CLK2:
• Baud = CLK_Freq/[(N + 1)*10]
• Where: N is in the range of 0 to 4095
• CLK1_Freq = 20 MHz
• CLK2_Freq = 9.216 MHz
• Special: Custom CLK2 available

Typical Baud Rates
Baud	Clock	Prescale (N)		Baud	Clock	Prescale (N)
300	CLK2	3071		57,600	CLK2	15
600	CLK2	1535		115,200	CLK2	7
900	CLK2	1023		230,400	CLK2	3
1,200	CLK2	767		460,800	CLK2	1
1,800	CLK2	511		921,600	CLK2	0
2,400	CLK2	383		12,500	CLK1	159
3,600	CLK2	255		25,000	CLK1	79
4,800	CLK2	191		50,000	CLK1	39
7,200	CLK2	127		100,000	CLK1	19
9,600	CLK2	95		200,000	CLK1	9
14,400	CLK2	63		250,000	CLK1	7
19,200	CLK2	47		400,000	CLK1	4
28,800	CLK2	31		500,000	CLK1	3
38,400	CLK2	23		1,000,000	CLK1	1

• Start bits: 1
• Data bits: 8
• Parity: Odd/Even/Mark/Space/None
• Stop bits: 1
• But polarity: Normal/Inverted

• 4 Kbytes per transmitter
• 4 Kbytes per receiver
• FIFO threshold
• One per FIFO
• Settable as byte count
• Reports to Event Log List

• Insert in data stream
• Under software control
• Length: 1 - 255 bit times
• Repeatable for longer gaps
• Use to regulate or schedule transmissions

• S/W selectable slope: High/Low
• Special: Custom available

• Poll FIFO status
• Poll Event Log List
• Interrupts from Event Log List

• Transmitter over threshold
• Transmitter underflow (empty)
• Receiver under threshold
• Receiver overflow (full)
• Receive error

• Access to other board resources (IRIG time and digital I/O)
• Easy-to-use functions

Example Configurations

Serial Configurations for 2 Modules

• Up to 8 Serial UARTs
• 8 Serial UARTs plus 8R/8T ARINC 429 channels
• 4 Serial UARTs plus 12R/12T ARINC 429 channels
• 4 Serial UARTs plus 4R/4T ARINC 429 channels and 2R/2T ARINC 708 channels
• 4 Serial UARTs plus 4R/4T ARINC 429 channels and 1 or 2 MIL-STD-1553 channels

• Up to 16 Serial UARTs
• 4 Serial UARTs plus 28R/28T ARINC 429 channels
• 4 Serial UARTs plus 8R/8T ARINC 429 channels plus 4R/4T ARINC 717 channels plus 2T/2T ARINC 708 channels and 1 or 2 MIL-STD-1553 channels

Software

The easiest way to use OmniBus serial products in a Windows® environment is with Ballard's graphical CoPilot® software when they are used with ARINC 429 channels on the same board. CoPilot can host multiple cards, channels, and databuses (ARINC 429, ARINC 708, MIL-STD-1553, and serial), so it is the ideal tool for OmniBus products.

Alternatively, users can develop their own software using the included BTIDriver™ API. Although each OmniBus product can be easily configured and run with only a few API calls, the comprehensive library includes a broad range of functions for specialized needs.

An SDK is available for advanced users who are developing software to run on the PowerPC.

Ordering Information

OmniBus Order Numbers—The order number for an OmniBus product is a combination of the board part number (see table below) and module part number(s).

	1 Core	2 Cores	4 Cores
PCI (short)	111	112	—
cPCI (3U)	121	122	—
VME (6U)	—	152	154
Ethernet/USB	—	162	—

ARINC 429 Module Part Numbers—The table below lists standard serial interface modules. Contact Ballard for more details.

P/N	Description
432	4 Serial UARTs
436	4 Serial UARTs with 4R/4T ARINC 429