The command:

$ online -mca

launches a MCA widget. The purpose of this applications is to check the operational status of the MCA, look at count rates, adjust ROIs.

Related error: The MCA feature required some changes in Spectra and also in ./ This file is automatically created by Spectra in the process working directory, if it does not exist. The following error may occur, e.g.:

open 'mca' No such file or directory at /home/pXXuser/temp/ line 60.

User action: delete and restart 'online -mca'.