Emergency Lighting - Understanding

[charzree]

Kindly refer the attached Image. There are 2 Places at which I can give reference signals for Emergency lighting.

1. At MXC
2. At LTC (Unswitched & Switched)

What is the difference between the above two? why there is a need to provide input at two different locations?

 

[The Ghost]

The LTC is part of the EMEX MXC automatic emergency lighting testing system, and can control the lamp and dimmer signal when testing. It measures the lamp power consumption and communicates this and the lamp status back to the EMEX central PC using power line communication via the MXC substation. It is fully addressable and programmable for any lamp type or configuration. This is done in situ from the central PC.