SCADA Systems Flashcards
7 cards from real SOPD practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 SCADA Systems flashcards as text
What is the primary function of a Remote Terminal Unit (RTU) in a SCADA system?
Answer: Collect field data and transmit it to the master station
RTUs collect analog and digital data from field devices and transmit it to the SCADA master station for monitoring and control.
In SCADA communications, what does the term 'polling' refer to?
Answer: A method where the master station periodically queries each RTU for data
Polling is a master-initiated communication method where the control center sequentially queries each RTU to retrieve current status and measurements.
Which SCADA display element is used to show the real-time state of a circuit breaker as open or closed?
Answer: Status point (digital point)
Status points (digital points) represent two-state or multi-state equipment conditions such as breaker open/closed positions on SCADA displays.
What distinguishes a Supervisory Control and Data Acquisition (SCADA) system from a Distributed Control System (DCS)?
Answer: SCADA is designed for geographically dispersed sites while DCS manages localized continuous processes
SCADA systems are optimized for monitoring and controlling assets spread over large geographic areas, whereas DCS systems focus on continuous process control within a single facility.
When a SCADA system shows a 'stale' data indication, what does this mean for the operator?
Answer: The data has not been updated within the expected scan interval
Stale data indicates that the SCADA master has not received a fresh update from the RTU within the configured scan cycle, suggesting a communication or RTU issue.
Which protocol is most commonly used for SCADA communication in North American electric utility systems?
Answer: DNP3 (Distributed Network Protocol 3)
DNP3 is the dominant SCADA communication protocol in North American electric utilities due to its reliability, time-stamping capability, and support for unsolicited reporting.
What is the purpose of the 'tag database' in a SCADA system?
Answer: Map communication addresses to human-readable point names and engineering units
The tag database associates RTU register addresses with descriptive point names, scaling factors, and engineering units so raw data can be displayed meaningfully to operators.