External Signals

The External Signals page is available only for chromatogram snippets where multiple signals are plotted. For example:

• Chromatograms With m/z Labels

• Chromatograms With Compounds

• Multi MS Chromatogram Separated

• Multi Signal Plot Overlaid

• Multi Signal Plot Separated

• Multi Signal Plot With Reference Chromatogram

• Parameterized Chromatogram

Using external signals allows you to add up to three signals to your chromatogram that are independent of the current scope. For example, if your chromatogram shows the signal of an unknown sample, you can overlay the specific signal of a calibration standard.

NOTE

The external signal plot ignores all annotation settings, labels, or legends, that you configure for the regular signal.

Show External Signals	Select the check box to activate the display of external signals.
Signal ID Expression	Provide an expression that returns the relevant signal ID. You can configure up to three signal IDs. The signals are applied in the order they appear in the list.
	Move the selected expression upwards.
	Move the selected expression downwards.
	Remove the selected expression.

To get the signal ID dynamically, consider the following approaches:

• In a single sequence template, prepare a hidden table. Filter the table so that only the relevant signal remains. Save the signal ID to a variable.

• In a single sequence template, prepare a hidden composite group. Filter the group so that only the relevant signal remains. Save the signal ID to a variable.

NOTE

Default calculation variables can store only numerical values. You may use custom code to create a string variable. See Example: Store a string value in a variable.