ARINC 429 vs. ARINC 664

Attribute	ARINC 429	ARINC 664
Data Rate	100 kbps	100 Mbps
Physical Layer	Electrical	Optical
Protocol	Point-to-point	Switched
Application	Avionics	Avionics

Introduction

ARINC 429 and ARINC 664 are both widely used data bus standards in the aviation industry. While they serve similar purposes, there are key differences between the two that make them suitable for different applications. In this article, we will compare the attributes of ARINC 429 and ARINC 664 to help you understand their strengths and weaknesses.

ARINC 429 Overview

ARINC 429 is a simple, point-to-point data bus standard that has been in use for decades. It is a unidirectional bus, meaning that data flows in only one direction at a time. ARINC 429 operates at a speed of 100 kilobits per second and uses a differential voltage signal for communication. This standard is commonly used for transmitting basic flight data, such as altitude, airspeed, and heading information.

One of the key advantages of ARINC 429 is its simplicity and reliability. It is a proven technology that is widely supported by avionics manufacturers and is relatively easy to implement in aircraft systems. However, its limited bandwidth and unidirectional nature can be a drawback for more complex avionics systems that require higher data rates and bidirectional communication.

ARINC 664 Overview

ARINC 664, also known as AFDX (Avionics Full-Duplex Switched Ethernet), is a newer data bus standard that was developed to address the limitations of ARINC 429. Unlike ARINC 429, ARINC 664 is a full-duplex, switched Ethernet network that supports bidirectional communication and higher data rates. It operates at speeds of up to 100 megabits per second and can handle multiple virtual links simultaneously.

ARINC 664 is designed to provide deterministic, high-speed communication for critical avionics systems, such as fly-by-wire flight controls and engine management systems. Its full-duplex nature allows for real-time monitoring and control of aircraft systems, making it ideal for applications that require fast and reliable data transfer. However, the complexity of ARINC 664 can make it more challenging to implement and maintain compared to ARINC 429.

Comparison of Attributes

• Data Rate: ARINC 429 operates at 100 kilobits per second, while ARINC 664 can achieve speeds of up to 100 megabits per second.
• Communication: ARINC 429 is unidirectional, while ARINC 664 is full-duplex and supports bidirectional communication.
• Reliability: ARINC 429 is a proven technology with a long track record of reliability, while ARINC 664 is newer and may have more potential for issues.
• Complexity: ARINC 429 is simpler and easier to implement, while ARINC 664 is more complex and may require more expertise to set up and maintain.
• Applications: ARINC 429 is suitable for basic flight data transmission, while ARINC 664 is better suited for high-speed, critical avionics systems.

Conclusion

In conclusion, both ARINC 429 and ARINC 664 are important data bus standards in the aviation industry, each with its own strengths and weaknesses. ARINC 429 is a reliable and simple solution for basic flight data transmission, while ARINC 664 offers higher data rates and bidirectional communication for critical avionics systems. The choice between the two standards will depend on the specific requirements of the avionics system being implemented.