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Snapshots

Snapshots are the core feature of Squirrel. A snapshot captures the values of all configured PVs at a specific point in time, allowing you to save, compare, and restore control system states.

What is a Snapshot?

A snapshot contains:

  • Timestamp - When the snapshot was created
  • Comment - A description of the snapshot purpose
  • PV Values - The setpoint and readback values for each PV at capture time

Viewing the Snapshot List

Navigate to Snapshots in the sidebar to see all saved snapshots.

The list shows:

  • Snapshot name/comment
  • Creation date and time
  • Number of PVs captured

Use the search bar to filter snapshots by name.

Creating a Snapshot

  1. Click the Create Snapshot button
  2. Enter a descriptive comment for the snapshot
  3. Click Create

Naming Conventions

Use descriptive comments that indicate the purpose or state, such as "Before maintenance" or "Baseline configuration 2024-01".

The snapshot will capture the current values of all configured PVs. A progress indicator shows the capture status.

Viewing Snapshot Details

Click on a snapshot name to view its details.

The details page shows:

Column Description
PV Name The process variable name
Saved Setpoint The setpoint value when the snapshot was taken
Saved Readback The readback value when the snapshot was taken
Live Value The current real-time value (updates automatically)
Severity Alarm severity indicator

Filtering PVs

Use the controls at the top to filter the PV list:

  • Search - Filter by PV name or device
  • Tag filter - Show only PVs with specific tags

Selecting PVs

Click the checkbox next to PVs to select them for:

  • Restore - Apply saved values back to the control system
  • Compare - Include in snapshot comparison

Deleting a Snapshot

Admin Required

Deleting snapshots requires admin privileges.

  1. Select the snapshot(s) to delete
  2. Click the Delete button
  3. Confirm the deletion

Deleted snapshots cannot be recovered.

Next Steps