I would avoid the DSC detectors like the plague, very issue prone on any panel other than DSC. We had multiple issues with them functioning properly in addition to huge QC issues. Also, to be frank, their design of their baseplate, testing method, even wiring plug, are very troublesome in the field, what I'd call poor engineering and execution.
Key points:
DSC devices work from a switched negative, whereas almost every panel in NA is switched positive. If you have existing smokes or ever need to replace one, you can't install a DSC on a fire loop with other manufacturer's 4 wire units, vice versa.
DSC smokes need a zone with the response time set for higher than 1.25 seconds, otherwise they are prone to cause phantom fire troubles based on their design. The are also prone to sending a "maintenance required" signal when it is not valid.
They do not maintain the wiring continuity when power is removed, while it may not be a problem for most, when attempting to troubleshoot, it's almost impossible without removing the detector itself.
There have been multiple issues with devices slipping past QC with bad drift compensation or sensitivity sections on their board...what this means is the detector will either false or not trip the zone. Only way this can be verified is either field testing and metering sensitivity using an appropriate canned smoke/tester.
The reversing relay in question will fire only on a pulsed temp 3 input, unless they made some major redesign changes to the circuit within the last year or so.
I wouldn't install multiple 4 wire fire zones with a reversing relay...it's an exercise with a lot of inherent issues, such as fire reset and multiple zones going into trouble when an alarm occurs or is reset after an alarm. If you go by the book, it looks like a good idea, however executing it successfully and being practical for usage are usually mutually exclusive items.
