SACA Study Guide 2026
Everything you need to pass the SACA exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 SACA Exam Format at a Glance
📚 SACA Topics to Study (76)
✍️ Sample SACA Questions & Answers
1. A Safety Instrumented System (SIS) with a Probability of Failure on Demand (PFD) between 10⁻¹ and 10⁻² is classified at which SIL?
SIL 1 corresponds to a PFD range of 10⁻¹ to 10⁻², representing the lowest level of safety integrity under IEC 61508.
2. Per IEC 60204-1, Stop Category 0 on a machine is defined as:
Stop Category 0 is an uncontrolled stop achieved by immediately removing power (or interrupting energy) to the machine actuators, which is the default safe state for E-stop functions.
3. In a cascade control system, which controller receives the process variable from the field sensor?
In cascade control, the secondary (slave) controller measures the inner loop process variable and receives its setpoint from the primary controller.
4. In a cyber-physical system, what is the primary function of the physical layer?
The physical layer in a CPS consists of sensors that measure real-world parameters and actuators that affect the physical environment, forming the bridge between the digital and physical worlds.
5. Which hydraulic circuit configuration is most energy-efficient for a system where multiple actuators rarely operate simultaneously?
A closed-center circuit with a pressure-compensated variable-displacement pump reduces flow to near-zero when actuators are idle, minimizing heat generation and energy waste.
6. In a hydraulic proportional valve system, what is hysteresis and why does it matter for closed-loop control?
Hysteresis is the output difference when a valve is approached from opposite directions, and in closed-loop systems it creates a deadband that limits positioning accuracy and must be compensated in the controller.