GPIB (IEEE-488) control: The principal advantage of the three-wire handshake (DAV, NRFD, NDAC) is that it accommodates devices with different speeds on the same bus. Choose the best completion.

Introduction / Context:The GPIB (IEEE-488) interface is a classic parallel bus used to connect instruments and controllers. Its robust three-wire handshake ensures reliable data transfers among devices with varying processing speeds.

Given Data / Assumptions:

• Handshake lines: DAV (Data Valid), NRFD (Not Ready For Data), NDAC (Not Data Accepted).
• Multiple devices (talkers/listeners) may have different internal latencies.
• Handshake controls data flow independent of raw cable speed.

Concept / Approach:The talker asserts DAV when data are stable. Each listener deasserts NRFD once ready, and later deasserts NDAC when the data is accepted. This closed-loop process waits for the slowest listener before proceeding, allowing a mix of fast and slow devices without data corruption.

Step-by-Step Solution:Talker places data on the bus.Listeners indicate readiness via NRFD.Talker asserts DAV; listeners latch data.Listeners assert NDAC low-to-high to acknowledge acceptance; bus advances to next byte.

Verification / Alternative check:Observe timing diagrams: data moves forward only when all handshake conditions are satisfied, regardless of individual device speeds.

Why Other Options Are Wrong:It is not inherently “faster”; it is robust and adaptable. Cable length is limited by spec, not enhanced by handshake. RS232C is a serial standard with different signaling.

Common Pitfalls:Assuming parallel automatically means fastest throughput; bus speed is governed by the slowest accepted handshake.

Final Answer:allows fast and slow listeners on the same bus