Data acquisition buses: A data acquisition (DAQ) subsystem may communicate over two common buses: a data bus and a control bus (with addressing provided separately or embedded). Assess the statement.
-
ACorrect
-
BIncorrect
-
COnly true with serial DAQs
-
DAmbiguous; buses are always three
Answer
Correct Answer: Correct
Explanation
Introduction / Context:DAQ systems interface sensors and actuators to processors. Communication structures vary (parallel buses, SPI/I2C, PCIe). Conceptually, interactions can be viewed as data transfer plus control/handshaking, which many curricula summarize as “data bus” and “control bus.” Addressing may be explicit (address bus) or encoded within control transactions, especially in serial protocols.
Given Data / Assumptions:
- General DAQ subsystem attached to a host processor or controller.
- Parallel or serial interconnects are possible.
- Address information may be carried on a dedicated bus or multiplexed.
Concept / Approach:The classical parallel microprocessor model uses three groups: address, data, and control. Many practical DAQ links collapse address into commands or registers accessed over the control path. Thus, describing communication in terms of a data bus (payload) and a control bus (commands, strobes, status) is acceptable in a generic sense, even though specific implementations may expose a separate address bus.
Step-by-Step Solution:
Identify payload path: data bus transfers samples, configuration values, and results.Identify orchestration: control bus conveys read/write strobes, chip selects, start/ready flags, interrupts.Addressing may be distinct (parallel bus) or embedded (serial command frames).Therefore the two-bus description is functionally valid for many DAQ contexts.Verification / Alternative check:Datasheets for ADC/DAC/DAQ cards show separate data width and control signaling; serial devices define command opcodes (control) distinct from payload bits (data).
Why Other Options Are Wrong:
- Incorrect: Overly rigid; many DAQ implementations follow the two-bus functional view.
- Only true with serial DAQs: Not limited to serial; applies to parallel too.
- “Always three buses”: Some designs multiplex address; “always” is false.
Common Pitfalls:Assuming a strict three-bus taxonomy in all systems; ignoring protocol-layer multiplexing of address within control frames.
Final Answer:Correct