In distributed data processing, the orderly method where a controller systematically queries each remote device or small computer for service is called what?

Introduction / Context:
When many subordinate devices share a controller or communication line, the system needs an orderly access method. One classic approach has the master ask each device in turn whether it has data to send or needs service, ensuring fairness and preventing collisions on shared media.

Given Data / Assumptions:

• Multiple remote devices or small computers participate in a shared system.
• Access is coordinated by a central controller.
• The method is systematic and cyclical.

Concept / Approach:
Polling is a master-driven access method wherein the controller sequentially queries (“polls”) each device. If a device has traffic, it transmits during its turn; otherwise, the controller moves on. Variants include roll-call polling and hub-go-ahead strategies. Polling contrasts with contention (e.g., CSMA) and scheduled token passing.

Step-by-Step Solution:
Identify the need for orderly, centrally coordinated access.Map this to the technique where the master queries subordinates in sequence.Conclude that the described method is polling.

Verification / Alternative check:
Legacy multidrop serial lines and many industrial fieldbuses used polling to guarantee deterministic behavior, especially where collisions or random access were unacceptable.

Why Other Options Are Wrong:
Dialed service: Refers to connection establishment, not access scheduling.

Multiplexing: Combines multiple signals/streams on one medium; not a query-based access protocol.

Conversational mode: Describes interactive behavior, not an access algorithm.

None of the above: Incorrect because polling is the standard term.

Common Pitfalls:
Confusing polling with interrupt-driven access; in polling, the master dictates timing rather than devices interrupting spontaneously.

Final Answer:
Polling