Scope displays message: "Character data not allowed" upon trying to send this command. Here's an example of what I'm sending using Python:
scope.write(':MEASure:MARK %s,%s' % ('testmeasure','ON'))
Where the name 'testmeasure' has already been added as a measurement and is returned from the the Query command outlined below.
Scope model is MSOV334A Infiniium Software Revision 06.40.01001