NEXSYS® Component Technology – Sensors & Detectors

ARINC 429 Multi-Bit Converter

ARINC 429 Signal Converter

The ARINC 429 Multi-Bit Converter (SR429/4M) from Applied Avionics can convert up to four different bits from a single ARINC 429 data label to discrete outputs. The polarity of the four outputs is selectable by bit. The SR429/4M is an 8-pin device, expandable to a 12-pin device.

The ARINC converter circuitry inside the SR429/4M includes an internal Health Monitor that can provide a “fail” indication if power to the decoder is lost or upon loss of valid ARINC data input. The Health Monitor has a range of watchdog timings requiring a valid ARINC label to be received within a specified time interval. The Health Monitor signal can be selected as one of the discrete outputs.

  • No software, firmware or programmable logic.
  • No stand-alone decoder required to achieve annunciation based on data bits.
  • Watchdog timer available to monitor validity of incoming ARINC data stream.
ARINC 429 Multi-Bit Converter Block Diagram

How it Works

The SR429/4M is an 8-pin device that converts up to four ARINC 429 data bits to discrete outputs. The polarity of each output (Open when Bit = 1 or Ground when Bit = 1) can be selected by bit. Bits can be repeated (taking two outputs) in order to get both polarities of the same bit. The internal Health Monitor can also be a selected output, with polarity option (Normal = Ground, Fail = Open or Normal = Open, Fail = Ground).

Additional Options

  • By increasing to a 12-pin package, the standard and inverted polarities of the four selected bits can be available.
  • Also in an expanded 12-pin package, the four discrete bits can be supplemented with a 2 X 4 decode of the two SSM bits (Bits 30 and 31) with polarity options. Additionally, the internal Health Monitor can be used in place of the SSM decode “00.”

ARINC 429 Multi-Bit Converter – Application Examples

To help system designers understand the potential of NEXSYS Component Technology, we have assembled a collection of Application Notes. The links below show example applications that utilize the ARINC 429 Multi-Bit Converter (SR429/4M)  component.

Door Status Indicator