It’s not so much a “black box”. It is a device, hooked into the transmitter system, that can automatically interrupt programming to activate the EAS. The operator doesn’t have to do a thing.
Each local and regional EAS operation areas have a selection of codes that they can program into the system to indicated if it’s just a test or an actual emergency. There are different codes for a local, regional, state, and national emergency, as well as for what the emergency is (weather, nuclear power plant meltdown, etc.). I believe the national emergency codes are the ONLY ones that can automatically override the broadcast signal. It doesn’t shut it off, it just puts the national message out without the local station operator having to do anything.
Having an FCC broadcast license automatically requires you to be part of the system. It isn’t optional. They don’t have to ‘bulldog’ anybody. They are already part of it, and..iff you want to broadcast over the air...willingly.
Hoagy62,
Anyone who knows how to push buttons on the front panel of an EAS unit or can access it over the management network (or with a laptop) can trigger a test. Monthly tests are required. Any tech who works at a cable headend can trigger the test. However, the designated primary station in each state usually triggers the monthly test that everyone uses. Proof of monthly tests must be kept on file for inspection as part of semi-annual FCC system sweep documentation.
National tests are not the only alerts that are required to be configured. Each alert type is given a priority during initial configuration and can be changed at any time. National tests are always configured at the highest priority.
The EAS can be turned off by pulling the power cord out of the outlet to which it is connected (assuming it is AC powered, some telcos use DC)