Time machine

When a fault occurs, operators and maintenance staff ask what happened before it. The time machine brings that moment back to the screen. Pumps, valves, tank levels, gauges and the alarm list show the selected moment. The recording can be played fast or slow, and you can move between screens.

• 2D screens, 3D scenes, menu bars and the alarm line are drawn with the recorded values.
• Alarm views show the current, unacknowledged and shelved lists of that moment.
• Trend views draw the archived time range that ends at the selected moment.
• You also see which screen the operator was looking at, where they clicked and which value they entered.

• The Time machine… button in the system menu.
• A key on the Live settings › Keyboard tab: the same key opens and closes the panel.
• The Open the time machine function in a button event. If a number is given as the value (e.g. 15), it goes that many minutes back.

The panel sits below the screen area. When it first opens, the screen is live.

When you tap an alarm triangle on the timeline, the recording starts playing at 1× from 30 seconds before the alarm. If the alarm has a source object, Live opens that object’s screen and highlights the object; in a 3D scene the camera moves to it. For going from an alarm to its object, see the Live alarms page.

Operator actions are marked below the alarms: values written to tags and rejected attempts. Actions taken in Live are blue, actions taken from a browser with remote control are orange, and rejected or unauthorized attempts have a red outline. Hovering over a mark shows the time, the user and the action. Tapping it plays the recording at 1× from 5 seconds before the action.

An orange frame appears around the screen area with a Replay label at the top; the replayed moment is shown next to the label.

• The plant runs live: alarm detection, scripts, scheduled tasks, the archive, reports and drivers work with live values. Browser and TV viewers see the live screen.
• No commands are given from the replayed screen. Tag writes from objects, event functions, recipe operations and alarm acknowledgment are not carried out; navigation between screens and 3D views work.
• If a new alarm comes in the plant, a red Live alarm notice flashes in the panel. Clicking it returns to live.
• If the screen is not touched for the set time (10 minutes by default), Live returns to live by itself.

Besides the values, the recording keeps which screen and which pop-up windows were open on the Live screen. While Follow Live screen is on, screens and windows change during replay as recorded. If you switch to another screen by hand, following stops for that replay; when you return to live, the screen from before the replay opens.

The input trail is recorded too:

• Mouse and touch movements, clicks.
• Special keys: Enter, Esc, Tab, arrows, F1–F12 and keys pressed with Ctrl or Alt.
• Open input windows, the on-screen keyboard and the focused field, with the value typed. The value of a password field is kept only as dots.

During replay the cursor, a click ring, the key name and the windows are shown where they were recorded; these windows cannot be clicked. The input trail is not a video recording; it is stored as the state of the screen.

If the time machine is on in the project, the screen trail and input trail of every user connected from a browser are also written on the Live computer, in a separate recording for each user. TV addresses are not recorded. The browser menu says that screen navigation is recorded. The extra monitors of the separate page on each monitor layout also get their own recording.

• In the Screen selection on the panel, choose the Live computer, an extra monitor or a user; the replay shows that screen.
• The times when the selected user was connected appear on the timeline as a purple line. If the user was not connected at that moment, the panel says so.
• Tapping the mark of an action taken with remote control switches to that user’s screen.

Live writes the changed values every 0.5 seconds, and a full copy of all values and the alarm list every five minutes. Recordings go into hourly files in the project’s data folder; completed hours are compressed. Values with bad quality (connection lost, address error) also appear with bad quality during replay.

• Values are sampled every 0.5 seconds; shorter changes may not be recorded.
• The time machine opens only on the Live computer. In a redundant server pair the master writes the recording.
• The disk space used depends on the number of tags, how often the values change and the number of connected users.