ARINC 429/575 Six Channel, Tx/Rx (Module A4)68C3 Operations Manual North Atlantic Industries, Inc. 12/19/2014Rev: 2014-12-19-0947 www.naii.com Page 51 of 330ARINC 429/575 SIX CHANNEL, TX/RX (MODULE A4)Features Receive / Transmit mode programmable / per channel 100 KHz or 12.5 KHz operation per channel Transmit: 255 word FIFO or scheduled transmits per channel Async transmits during scheduled transmits Receive: 255 word FIFO or mailbox buffering per channel SDI/Label filtering programmable / per channel AR429 or 575 mode programmable / per channel Selectable hardware parity generation/checking Receive time stamping Double buffered Rx / Tx Continuous BIT Loop-back test Tri-stateable Outputs Hi and Lo speed Slew Rate OutputsARINC 429/575 OverviewARINC 429 is the most commonly used data bus for commercial and transport aircraft. It employs unidirectionaltransmission of 32 bit words over two wire twisted pairs using bipolar RZ format. Messages are transmitted at12.5 kbps, or 100 kbps to other system elements that are monitoring the bus messages. The transmitter is alwaystransmitting either 32-bit data words or the Null state. ARINC SPECIFICATION 429 PART1-16 defines theelectrical standard, data characteristics and protocols.ARINC 575 is an older specification very similar to ARINC 429 but now obsolete. Electrically, ARINC 575 isgenerally compatible with low speed ARINC 429. There are some ARINC 575 implementations that use a bit ratethat is much slower than ARINC 429 and are not electrically compatible. Also, in some cases, ARINC 575 wordsuse bit 32 as parity (as does ARINC 429); in other cases bit 32 is used as data.Functional DescriptionThe AR429 module provides up to six programmable ARINC-429 channels. Each channel is software selectablefor transmit and/or receive, Hi or Lo speed, and odd or no parity. Thus the module can support multipleARINC429 and 575 channels simultaneously.SerialtoParallelConversionLABEL / SDIVALIDATIONFILTERWD GENERATIONRCVBUFFER255 wdsTXBUFFER255 wdsARINC429ARINC575BUSMODULEBUSINTERFACEUSERPROGRAMMABLEVME / PCIINTERFACEConfigurable Rcv/Txmit ARINC ChannelConfigurable Rcv/Txmit ARINC ChannelCONTINUOUS BITFEEDBACKTRANSIENTPROTECTION LOOP BACK
