2 way linking 2 fire panels with 2 core cable

[FireFly40]

The 2 cores between each panel go to a 4pole relay dioded so that a + and - from panel A operate the relay in panel B and vice versa. The feed to the relay coil in each panel goes through its own NC contacts (in case other panel goes into fire when link active). The spare contact is used for the class change in each panel. If no class change use both spares for direct 24v up bell lines. Theoretically you could monitor the connection from one end if you used another relay in one panel and a spare zone or bell line, but never had the need to do that. Its a while since I did it but have drawing if anyone still interested. Only just logged on here and read that someone was having problem (probably years ago and sorted now!!) apologies

[Wiz]

Hi FireFly,

Just returned from hols and only just seen your post.

 Please note:

1) This area of the site is really only for Q&A regarding RRO. But now that you've started, we might as well finish!

2) I think that you are referring to a post made elsewhere on the site regarding connecting two fire panels over a single two core cable but providing signals in both directions. I am having great problems understanding your description. I have read it a few times, but I still can't get my head around it. Can you please send me the drawing that you have?

[FireFly40]

Hi Wiz
 apologies for posting in wrong place I did realize but it was in the ether by then as explained I only just found this site and was so excited to know I wasnt the only sad old t**t messing with fire alarms on the planet. Im sure that other people look at porn or webcams of the bahamas etc. 25 years in fire alarms does rot your brain. Had to draw it on paint as stupid scanner doesnt work on new windows.
If problem opening ,email address and Ill post it.
If your into seeing how many signals you can get down the fewest wires Ive got better than that!