A. Voltage and current data from the main meter for the last 24 hours
B. Voltage and current data from all meters for the last day
C. Only current data from the main meter for the last hour
D. Voltage and current data from the main meter for the last hour
Solution
Step 1: Analyze data_source and metrics
The data_source is "main_meter" and metrics are ["voltage", "current"], so both voltage and current from main_meter are included.
Step 2: Check time_range value
The time_range is "last_1_hour", so data is from the last one hour only.
Final Answer:
Voltage and current data from the main meter for the last hour -> Option D
Quick Check:
Metrics + source + time range match Voltage and current data from the main meter for the last hour [OK]
Hint: Match metrics, source, and time range exactly [OK]
Common Mistakes:
Confusing time ranges (1 hour vs 24 hours)
Ignoring the specified data source
Selecting only one metric instead of both
4. You wrote this report schedule configuration:
{
"schedule": "daily",
"time": 25:00
}
What is the problem with this configuration?
medium
A. The time value 25:00 is invalid; hours must be 0-23
B. The schedule key should be "frequency" instead of "schedule"
C. The time value should be a number, not a string
D. The daily schedule is not supported in SCADA systems
Solution
Step 1: Check time format validity
Time values must be in 24-hour format with hours from 0 to 23. 25:00 is invalid.
Step 2: Verify other keys and values
The "schedule" key is valid, and daily schedules are supported. Time should be a string with quotes.
Final Answer:
The time value 25:00 is invalid; hours must be 0-23 -> Option A
Quick Check:
Invalid hour in time = The time value 25:00 is invalid; hours must be 0-23 [OK]
Hint: Use 24-hour time with hours 0-23 only [OK]
Common Mistakes:
Using hours above 23 in time
Omitting quotes around time string
Confusing schedule key names
5. You want to create a weekly energy report that shows total energy consumption and average power for multiple meters, but only for weekdays. Which configuration snippet correctly sets this up?
{
"data_source": ["meter1", "meter2"],
"metrics": ["total_energy", "average_power"],
"time_range": "last_7_days",
"filter": "weekdays"
} correctly uses a list for multiple meters and metrics, which is the proper format.
Step 2: Verify time_range and filter usage
{
"data_source": ["meter1", "meter2"],
"metrics": ["total_energy", "average_power"],
"time_range": "last_7_days",
"filter": "weekdays"
} uses "last_7_days" for time_range and "filter": "weekdays" to limit data to weekdays, which matches the requirement.
Step 3: Confirm schedule presence
Schedule is not mandatory here; filtering weekdays within last 7 days is sufficient.