Instrumentation software

1. CASE STUDY #2
Instrumentation software
Dr Reeja S R
Professor
CSE Dept.
SJEC, Vamanjoor, Mangalore

2. Tektronix Oscilloscope

3. Oscilloscopes
 Evolution of oscilloscopes
 Applications:
 Maintenance of electronic equipments
 Analyzing automation ignition systems, testing sensors
and output signals
 Display waveform of heartbeat as ECG

4. Problems
 Little reuse across oscilloscope products
 Different products are built differ
 Introduction of new hardware/UI would require software
redesign from scratch
 Custom products were built for specialized markets
 Performance problems because software could not be
easily reconfigured

5. The purpose of this project was to develop a reusable
software architecture to be shared among a number of new
oscilloscope products.
The result of that work was a domain-specific software
architecture that formed the basis of the next generation of
oscilloscopes.

6. Soln #1: Object Oriented Approach

7. Soln #1
 Drawbacks
 No overall model could be established
 Confusion about division of functionality
 Confusion about which objects are allowed to interact with
user

8. Soln #2: Layered Approach

9. Soln #2
 Drawbacks
 wrong model for the application domain
 boundaries of abstraction enforced by the layers conflicted
with the needs for interaction among various functions

10. Soln #3: Pipes and Filters
Oscilloscope functions were viewed as incremental transformers of data:
•Signal transformer: to condition external signal.
•Acquisition transformer: to derive digitized waveforms
•Display transformers: to convert waveforms into visual data.

11. Soln #3
 Advantages:
 Functions are no longer isolated into separate partitions
 Data flow nature of signal processing is reflected
 Allows intermingling and substitution of software and
hardware components
 Disadvantages:
 Does not enable the user to interact with the system

12. Modified Pipes and Filters