---
title: "Types of microprocessor based instrumentation systems"
subject: "Instrumentation II"
chapter: 1
key: "semester_5/instrumentation_ii:mbi-types"
source: https://www.bctengineer.com/q/semester_5/instrumentation_ii/mbi-types
site: BCT Engineering
---

# Types of microprocessor based instrumentation systems

Instrumentation II · Chapter 1: Microprocessor Based Instrumentation System

- Asked in: 2069 Chaitra, 3 marks
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/instrumentation_ii/mbi-types
- Whole chapter: https://www.bctengineer.com/md/semester_5/instrumentation_ii/chapter-1

## Question

What are the types of Microprocessor based system used in instrumentation system? How it makes more benefits in industry?

## Short answer

Types: data acquisition, open-loop control, closed-loop PID, supervisory (SCADA), stand-alone/embedded, distributed, PC-based. Benefits: accurate automatic control, many loops handled by one unit, fast alarms, software flexibility, data logging, remote monitoring, reduced manpower and downtime.

## Answer

Microprocessor based systems used in instrumentation can be classified as follows.

1. **Data acquisition (monitoring) systems:** only measure, process, display and record variables; no control action. Example: digital multimeter, data logger.
2. **Open loop control systems:** the processor gives control outputs without feedback. Example: sequential timer control, traffic lights.
3. **Closed loop control systems:** output is fed back; the processor corrects the error (DDC, PID). Example: furnace temperature or motor speed control.
4. **Supervisory systems:** the processor sets set points of local controllers and monitors (SCADA, PLC).
5. **Stand-alone (single processor / embedded) vs. distributed (multiprocessor) systems:** distributed systems place several processors near the sensors, connected by a network.
6. **PC-based systems:** a computer with plug-in DAQ card and software.

#### Benefits in industry
- Accurate, automatic and consistent control, giving better product quality.
- One processor handles many channels, reducing cost and wiring.
- Fast alarms and safety shutdown.
- Easy modification by software and easy expansion.
- Data logging and remote monitoring, less manpower and downtime.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What does a data acquisition (monitoring) system do?
   A. Measures, processes, displays and records variables with no control action
   B. Corrects errors by feedback
   C. Sets set points of local controllers only
   D. Drives actuators
   Answer: A. It monitors only; example is a data logger. (Key point: Data acquisition systems)

2. What is a supervisory system?
   A. A system without any processor
   B. Processor sets set points of local controllers and monitors them (SCADA, PLC)
   C. A single sensor
   D. A manual panel
   Answer: B. Supervisory systems oversee local controllers. (Key point: Supervisory system)

3. What characterises a distributed system?
   A. One processor for everything
   B. No network
   C. Several processors near the sensors connected by a network
   D. Only analog parts
   Answer: C. Distributed means multiprocessor with network links. (Key point: Distributed system)

## Related in Instrumentation II

- [Features of microprocessor based instrumentation](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ambi-features) — Instrumentation II, chapter 1, asked 4×
- [Microprocessors in instrumentation systems (case study)](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ambi-casestudy-statement) — Instrumentation II, chapter 1
- [MBI block diagram and advantages in industry](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Ambi-block-advantages) — Instrumentation II, chapter 1
- [Rationale for microprocessor; open-loop MBI; DMA](https://www.bctengineer.com/question.md?key=semester_5%2Finstrumentation_ii%3Arationale-open-loop-dma) — Instrumentation II, chapter 1

## Related in other subjects

- [Microprocessor based system and bus organization](https://www.bctengineer.com/question.md?key=semester_4%2Fmicroprocessor%3Amp-based-system-bus-organization) — Microprocessor, chapter 1, asked 5×
- [Benefits of computer based control](https://www.bctengineer.com/question.md?key=semester_6%2Fembedded_system%3Acomputer-based-control-benefits) — Embedded System, chapter 7
- [Microprocessor-based transmission line protection](https://www.bctengineer.com/question.md?key=semester_6%2Fswitchgear_and_protection%3Amicroprocessor-line-protection) — Switchgear and Protection, chapter 8, asked 2×
- [Tariff types used in industry billing by NEA](https://www.bctengineer.com/question.md?key=semester_7%2Futilization_of_electrical_energy%3Atariff-types-nea-industry) — Utilization of Electrical Energy, chapter 6