SACA Cheat Sheet 2026

The 30 highest-yield SACA facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. In robotic systems, what is the purpose of end effectors? → To interact with objects and perform tasks
2. Which protocol suite is specifically designed for wireless communication in industrial CPS environments requiring low power and mesh networking? → WirelessHART / ISA100.11a
3. Which type of motor is most commonly paired with encoder feedback for precise position control in industrial robots? → Brushless DC servo motor
4. In PLC network communications, what does the term 'master-slave' topology refer to? → One device initiates all communications and others respond only when polled
5. A V-belt drive system begins slipping under load. Which corrective action would be MOST effective without replacing belts? → Adjust the center distance to restore proper tension
6. When two meshing spur gears have different numbers of teeth, which property is the SAME for both gears? → Tooth pitch (diametral pitch or module)
7. In a CPS, what is the function of an actuator? → To convert control signals into physical action
8. In pneumatic systems, what does the ISO symbol for an FRL unit represent? → Filter-Regulator-Lubricator — conditions compressed air for downstream use
9. During a collaborative robot (cobot) risk assessment, which hazard category requires the lowest priority mitigation effort? → Residual hazards with negligible probability and minor severity
10. In a smart grid CPS, what is the role of a Phasor Measurement Unit (PMU)? → To provide high-frequency, GPS-synchronized measurements of voltage and current phasors
11. What does LOPA stand for in functional safety risk assessment? → Layers of Protection Analysis
12. Which statistical test would you use to determine if defect rates differ significantly across three production lines? → Chi-square test or ANOVA
13. Which of the following best describes the role of sensors in a cyber-physical system? → To provide data input by measuring physical phenomena
14. What is a key characteristic of a cyber-physical system (CPS)? → It integrates computation with physical processes.
15. A double-acting hydraulic cylinder is not extending fully under load. Which diagnostic check should be performed first? → Check system pressure at the cylinder port against the load requirement
16. A factory wants to predict equipment failure 48 hours in advance. Which analytics approach is most suitable? → Predictive analytics using historical sensor data and ML models
17. A maintenance technician uses a vibration analyzer and finds a dominant frequency peak at exactly 1× running speed. This signature most likely indicates: → Mass imbalance in the rotating component
18. In Ladder Diagram programming, what does an 'XIC' (Examine If Closed) instruction do when the referenced bit is FALSE (0)? → It blocks continuity (prevents power flow), acting like an open switch
19. What is the primary purpose of data normalization in factory analytics pipelines? → To scale features to a common range for fair model comparison
20. What does SIL stand for in the context of industrial functional safety? → Safety Integrity Level
21. Which metric measures the proportion of time a machine is actually producing versus its scheduled production time? → Machine Availability Rate
22. Which type of robot drive system provides the highest positional accuracy and eliminates backlash, making it ideal for precision machining applications? → Electric servo motor with harmonic drive gearbox
23. What does the IEC 61131-3 standard define? → Five standard programming languages for programmable controllers
24. What is the function of a PLC's retentive coil (or latching coil)? → It maintains its state even when its enabling condition goes false
25. In cyber-physical system design, what does 'functional safety' (IEC 61508) address? → Ensuring the system performs correctly even under fault conditions to avoid hazards
26. What does 'Hardware Fault Tolerance' (HFT) of 1 mean for a safety subsystem? → The subsystem can still perform its safety function with one fault present
27. What is feature engineering in the context of factory machine learning models? → Creating derived input variables from raw data to improve model performance
28. Which security threat is most specific to cyber-physical systems compared to traditional IT systems? → Physical damage via manipulated control signals
29. What is the role of edge computing in modern cyber-physical systems? → To process data near the source to reduce latency and bandwidth usage
30. In mechatronics, what is the purpose of a planetary gearbox attached to a servo motor? → To increase torque and reduce speed while maintaining compact dimensions