Arinc 429 Serial Port Adapter

The RTX ASA429 is the larger cousin to our well known SPA429. The ASA429 can connect up to 16 ARINC 429 channels to a PC or any other processor that has either a serial interface, or a USB interface. The ASA429 has connections for both a RS232 port and also a USB port. Either port can be used to connect to the ASA429. The USB port appears to the PC as just another High Speed RS232 port. The ASA429 can also support 4 discrete outputs. There are no restrictions on the number of labels that can be transmitted or received. The RTX ASA429 can be purchased to transmit on as many as 8 ARINC channels and receive from 8 ARINC channels simultaneously. All receive and transmit channels can be independently configured to operate either at high speed (100 Kbps) or low speed (12.5 Kbps) data rates. The RTX ASA429 can process all 16 channels at full data rates. When used with your software, or with our VORTEX Windows GUI, the RTX ASA429 can be the heart of a powerful and sophisticated ARINC 429 system that is versatile, portable, inexpensive, and easy to use.


The ARINC 429 Transmitters

There can be up to 8 ARINC 429 transmit channels on the RTX SPA429 adapter. In order to command the RTX ASA429 to transmit an ARINC 429 data word, 5 bytes of data need to be sent to it via the serial port that the RTX ASA429 is attached to (i.e. the RS232 or the USB port). Any application, on any computer, using any operating system, that can send 5 bytes of data to an RS232 serial port, can transmit ARINC 429 words. The 5 bytes which are send to the RTX ASA429, are combined by the adapter, to form the 32 bit ARINC 429 word which is then transmitted on the specified ARINC channel. The RTX ASA429 will automatically generate an appropriate parity bit.

The ARINC 429 Receivers
In a manner similar to the transmission of ARINC 429 data, the RTX ASA429 receivers translate each incoming 32 bit ARINC 429 data word into 5 bytes and sends them to the attached RS232 serial port. Any application, on any computer running with any operating system that can read 5 bytes of data from a RS232 serial port, can read from an ARINC 429 data bus. ARINC data words can be buffered within the RTX ASA429 adapter. If the host computer is unable to keep up with the incoming data, the RTX ASA429 will buffer up to 512 incoming ARINC 429 data words, without loosing any data. The RTX ASA429 can also filter incoming ARINC 429 data word, if desired. By software command, the RTX ASA429 adapter can be configured to reject or accept any number of labels, and only allow through specified labels. Each channel can have its own separate, independent list of labels which will be allowed to pass. This eliminates the need for software to scan all the incoming data, for labels of interest.

The Software Interface
The RTX ASA429 adapter is provided, at no additional cost, with the RTX Applications Program Interface (API), which is a Windows only interface. The RTX ARINC 429 API enables user written software the functional capability to transmit and receive any data on any channel. The API converts high level User Commands into the 5 byte RTX format. It also provides the ability to setup the RTX ASA429 adapter to filter out (or allow through) any label(s) desired, on a per channel basis. There is no limit to the number of labels that can be enabled or disabled. Using the API, a programmer can access the functions of the SPA, without regard to the details of the hardware interface to the RTX ASA429 adapter, eliminating the need to convert the data between 32 bits ARINC words and the 5 byte RTX format. The API is in the form of a Windows DLL, and any program which can interface with a Windows DLL, such as LabView, can utilize the RTX ARINC 429 API. There is no additional cost for the API, and no licensing fees. This API is common and compatible to with the RTX SPA429 and the RTX ASA429 family of products.

RTX also sells VORTEX,a Windows based Graphical User Interface (GUI) which is perfect for most applications. The Vortex GUI provides access to all transmit and all receive functions of the RTX ASA429 adapter, in a Windows environment. In addition to simplifying transmission and reception of data on any channel, the Vortex GUI also can perform Engineering Units Conversion of data to be transmitted or received and real-time storing of incoming data onto a file, for later playback and analysis. The receive portion of VORTEX can display the received data in multiple formats: each ARINC word can be displayed on its own line, or only the most recently received ARINC word per label can be displayed. In addition, the VORTEX Aircraft Emulator Option (AEO), enables the capability to transmit a previously recorded data file, onto the SPA's transmit channels, thereby reproducing in the lab the ARINC 429 scenario as it was recorded in the field.

Optional Configurations
The RTX ASA429 product is available in multiple configurations of transmit and receive channel Part Number: RTX429/ASA-xTyR-D), where x is the number of receivers (from zero to 8) and y is the number of transmit channels (also from 0 to 8), and D implies that the ASA429 support 4 discrete output lines. The RTX ASA429 operates in the extended temperature range (-40 degrees C to +85 degrees C). The ASA can also be purchased as an ARINC 717/573 receiver, a multi-channel Combiner, and an ARINC429 to NMEA converter.