Logs

Follow the values of channels as lines of text while they arrive.

A log shows each new value of its channels as one line of text. Use a log to follow operator notes, the states of an automation, and slow sensors. A log can show channels of any data type, including text and JSON.

A log shows only values that arrive while it is open. It does not read stored data. To see stored data, use a line plot.

Create a log

1. Click in the tab bar, or press Ctrl+T (Cmd+T on macOS).
2. Select Log.
3. Click Configure channels, then click Add channel and select a channel.

You can also run the “Create log” command from the command palette. In the channels toolbar, double-click a virtual channel to open it in a log.

Add channels

1. Press V to open the component toolbar, then select the Channels tab.
2. Click Add channel and select a channel.
3. Optional: set an Alias to show in place of the channel name, and a color.

A number channel also has Notation and Precision settings. A timestamp channel has a timestamp format and a Time zone. To remove a channel and its lines, click Remove channel.

Pause and copy lines

Click (Pause scrolling) or press H to stop the log from scrolling. New lines still arrive. Scroll up to pause too. To resume, click or scroll back to the newest line.

To copy lines, drag across them, or press Ctrl+A (Cmd+A on macOS) to select all. Then press Ctrl+C, or right-click and select Copy.

Set what each line shows

On the Properties tab of the component toolbar:

The receipt timestamp is the time of day on your computer when the Console received the value. It is not the timestamp of the sample.

Limits

• A log keeps up to 100,000 lines and up to 7 days.
• Lines live only in the Console. Closing the tab or reloading the Console clears them.
• A value with more than one line of text shows as several lines.
• When a log opens, it can show the last minute of values of a channel that a different plot, schematic, or table already streams. These lines all show the time that the log opened.

Troubleshooting

The log says “No data received yet”

Cause

Nothing has written to the channels since the log opened. A log does not show stored data.

Fix

Check that a task, a script, or an Arc automation writes to the channels, or use a line plot for stored data.

A line shows the wrong time

Cause

The receipt timestamp is the time that the Console received the value, not the time of the sample.

Fix

To see when each sample was taken, plot the channel on a line plot.