Electrical Rules Check (ERC) in PCB Design - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding ERC Purpose

What is the main purpose of performing an Electrical Rules Check (ERC) in PCB design?

A To check the mechanical dimensions of the PCB for fitting in the enclosure.

B To generate the bill of materials for component purchasing.

C To optimize the PCB for thermal management and heat dissipation.

D To verify that the PCB layout matches the schematic connections and detect electrical errors.

💡 Hint

Think about what errors ERC is designed to catch related to electrical connectivity.

ERC is used to verify that the schematic's electrical connections are correct and to find issues like unconnected pins or conflicting connections.

❓ dax_lod_result

intermediate

Identifying ERC Error Count

Given a PCB design tool that outputs ERC errors as a table with columns: ErrorType and Count, which DAX expression correctly calculates the total number of ERC errors?

PCB Design

ERC_Errors = SUM(ERC_Table[Count])

A ERC_Errors = DISTINCTCOUNT(ERC_Table[ErrorType])

B ERC_Errors = COUNTROWS(ERC_Table)

C ERC_Errors = SUM(ERC_Table[Count])

D ERC_Errors = AVERAGE(ERC_Table[Count])

💡 Hint

Think about how to sum all error counts, not just count rows or distinct types.

Summing the Count column gives the total number of errors across all types.

❓ visualization

advanced

Best Visualization for ERC Error Types

You want to create a dashboard showing the distribution of different ERC error types and their counts. Which visualization type best communicates this information clearly?

A A stacked bar chart showing error counts by error type.

B A pie chart showing the percentage of each error type out of total errors.

C A scatter plot mapping error severity versus error count.

D A line chart showing error counts over time.

💡 Hint

Consider which chart type clearly compares counts across categories.

A stacked bar chart clearly shows counts per error type and allows easy comparison between them.

🔧 Formula Fix

advanced

Debugging ERC Error Filtering

In a report, a filter is applied to show only 'Short Circuit' ERC errors, but the report still shows other error types. Which DAX filter expression correctly filters only 'Short Circuit' errors?

PCB Design

FILTER(ERC_Table, ERC_Table[ErrorType] = "Short Circuit")

A FILTER(ERC_Table, ERC_Table[ErrorType] == "Short Circuit")

B FILTER(ERC_Table, ERC_Table[ErrorType] = "Short Circuit")

C FILTER(ERC_Table, ERC_Table[ErrorType] != "Short Circuit")

D FILTER(ERC_Table, ERC_Table[ErrorType] = Short Circuit)

💡 Hint

Check the correct syntax for string comparison in DAX.

DAX uses a single equals sign for comparison and strings must be in quotes.

🎯 Scenario

expert

Scenario: Prioritizing ERC Errors for Fixing

You have a list of ERC errors with columns: ErrorType, Severity (High, Medium, Low), and Count. You want to create a calculated measure that sums counts only for High severity errors to prioritize fixing. Which DAX expression achieves this?

A HighSeverityErrors = SUMX(FILTER(ERC_Table, ERC_Table[Severity] = "High"), ERC_Table[Count])

B HighSeverityErrors = CALCULATE(SUM(ERC_Table[Count]), ERC_Table[Severity] = "High")

C HighSeverityErrors = SUM(ERC_Table[Count]) WHERE ERC_Table[Severity] = "High"

D HighSeverityErrors = SUM(ERC_Table[Count]) IF ERC_Table[Severity] = "High"

💡 Hint

Think about how to filter rows before summing in DAX.

SUMX with FILTER correctly sums counts only for rows where Severity is High.