Decides which agent will trigger capture of the image.

Values of this enumeration:

• Software
• Line1
• Line2
• Line3
• Line4
• Line5
• Line6
• Line7
• Line8
• CC1
• CC2
• CC3
• CC4
• Timer1Start
• Timer1End
• Counter1Start
• Counter1End
• UserOutput1
• UserOutput2