Which statement best contrasts ARINC 429 and ARINC 629 regarding topology and fault tolerance?

Which statement best contrasts ARINC 429 and ARINC 629 regarding topology and fault tolerance?

• A. ARINC 429 is point-to-point or simple multi-drop with single fault tolerance; ARINC 629 is dual-redundant, multi-drop bus with higher fault tolerance.
• B. ARINC 429 is dual-redundant, multi-drop bus with higher fault tolerance; ARINC 629 is simple point-to-point.
• C. ARINC 429 uses bus topology with full redundancy; ARINC 629 is point-to-point.
• D. Both are identical in fault tolerance but different speeds.

Answer: (A)

Understanding topology and fault tolerance shows why this contrast is correct. ARINC 429 is essentially a one-transmitter network with multiple receivers, a point-to-point or simple multi-drop arrangement. It provides basic fault tolerance, but there isn’t built-in redundancy across the whole network; if the transmitter or a segment fails, data on that link is affected. ARINC 629 uses a dual-redundant, multi-drop bus. Two separate bus backbones carry the data, and the system can switch to the redundant path if a fault occurs, providing higher fault tolerance and continued operation for critical data. So, the statement that ARINC 429 is point-to-point or simple multi-drop with single fault tolerance, while ARINC 629 is dual-redundant, multi-drop with higher fault tolerance, captures the key difference. The other options misstate the topology or redundancy, such as claiming both have the same fault tolerance or that ARINC 629 is point-to-point.

Understanding topology and fault tolerance shows why this contrast is correct. ARINC 429 is essentially a one-transmitter network with multiple receivers, a point-to-point or simple multi-drop arrangement. It provides basic fault tolerance, but there isn’t built-in redundancy across the whole network; if the transmitter or a segment fails, data on that link is affected.

ARINC 629 uses a dual-redundant, multi-drop bus. Two separate bus backbones carry the data, and the system can switch to the redundant path if a fault occurs, providing higher fault tolerance and continued operation for critical data.

So, the statement that ARINC 429 is point-to-point or simple multi-drop with single fault tolerance, while ARINC 629 is dual-redundant, multi-drop with higher fault tolerance, captures the key difference. The other options misstate the topology or redundancy, such as claiming both have the same fault tolerance or that ARINC 629 is point-to-point.