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Snapshot Comparison

The comparison view lets you see differences between two snapshots side by side, making it easy to identify what changed between configurations.

Starting a Comparison

There are two ways to start a comparison:

From Snapshot Details

  1. Open a snapshot's details page
  2. Click the Compare button
  3. Select the second snapshot to compare against

From the Snapshot List

  1. Select two snapshots using the checkboxes
  2. Click the Compare button

Understanding the Comparison View

The comparison displays PVs in a table with columns from both snapshots:

Column Description
PV Name The process variable name
Main Setpoint Setpoint value from the first (main) snapshot
Main Readback Readback value from the first snapshot
Compare Setpoint Setpoint value from the second snapshot
Compare Readback Readback value from the second snapshot

Color-Coded Differences

The comparison view highlights differences to make them easy to spot:

  • Highlighted rows - PVs where values differ between snapshots
  • Normal rows - PVs with identical values in both snapshots

Finding Changes Quickly

Use the filter options to show only PVs with differences, hiding identical values.

Filtering the Comparison

Use the controls at the top to focus on specific PVs:

  • Search - Filter by PV name
  • Show differences only - Hide PVs with identical values
  • Tag filter - Show only PVs with specific tags

Performance

The comparison view uses virtual scrolling to handle large numbers of PVs efficiently. Even with 10,000+ PVs, scrolling remains smooth.

Use Cases

Before/After Maintenance

Compare a "before maintenance" snapshot with an "after maintenance" snapshot to verify only intended changes were made.

Configuration Drift Detection

Compare the current state against a baseline configuration to identify unexpected changes.

Troubleshooting

Compare a "working" snapshot with the current state to identify what changed before a problem occurred.