Grass Valley Maestro Master Control Installation v.2.4.0 - Manual (Page 78)

78 MAESTRO Installation and Service Manual
Section 2 — Installation Planning
Insertion of Keys and Audio Overs
Any of the eight keyers and four audio over mixers can be triggered by an
external GPO (GPI in Maestro) signal. The GPI sub-system in Maestro that
enables this functionality is called the EAS (Emergency Alert System) sub-
system; however, any application in which external triggering of keyers
and audio over mixers is required may use the EAS sub-system.
Emergency Alert System Switching
In US installations, the GPIO connector on the Maestro rear panel can be
connected to an Emergency Alert System (EAS) receiver and configured to
select the EAS video and audio automatically on the Program output when
a trigger signal is received.