Modded Siren stop communicating to sc1200

[Brian H]

The ELK924 is a small PC Board with some electronics on it.
Powered by a 12 or 24 volt DC supply. Selected by a jumper.
Has a very low current trigger input. Does not load down the trigger source much.
Can be a + or - Trigger depending on which input you use on the terminal block.

ELK924 Web page. Both the specifications sheet and users manual are there for the download.
http://www.elkproducts.com/product-catalog/elk-924-sensitive-relay