Note that only the EMS has the contact output to power a panel light that you're asking about. Both the EFIS and EMS have the audio out though.
The EMS contact output is essentially a switch that completes a connection to ground when an alarm condition is present. It is constantly on when triggered. Essentially you would connect one end of the light to the EFIS (which is grounded when the alarm is activated) and the other end to a power source.
If you wanted a flashing light, there are lights/LEDs that can do this given the contact output that the EMS provides.
