More messing with Idratek - this time Cortex

Now that the Idratek bits have been running fine in the study for a couple of weeks, I want to move to actual 'trial' the kit rather than just play with it.

For me, the target application is improved control over the heating in the house - especially as it's got colder we've really started to notice considerable differences in heat levels between the 1st floor (which can be quite hot) and the 2nd floor (which stays chilly).

Ideally, each floor will be a zone, with some of the rooms on each floor having individual control (TRV as a minimum on the rest). But zoning the floors means draining down, adding zone valves. As the flow pipe junctions to the three floors are underfloorboards it also means some re-jigging of pipes to get space for the zone valves --- so not something that can be done yet.

So in the meantime, the plan is simply to use the idratek bits to monitor the 2nd floor and "override" the stat on the first floor until the 2nd floor gets up to heat -- as the existing stat is a simple volt-free contact closer, the intention is to wire an Idratek-controlled relay (in the DRB) across the same terminals.

First things first... to do this, I need to get Idranet upstairs, yet so far I've not found a suitable route to get cat5 from the 1st to the 2nd floor. BUT ... I suddenly remembered that the previous owners had had 2 phone extensions wired up to the 2nd floor. These were wired with alarm cable - 4 thin non-twisted cores. I'd disconnected them some months ago when I was trying to "clean" the internal wiring to improve DSL sync speeds, but had the sense to terminate them to small junction box on the 1st floor. Although the Idratek guides recommend that the network cable should be tristed pair, I thought it would be worth trying this alarm cable out -- just for this short run to the 2nd floor. After reading someone had managed to use a piece of twin-and-earth I was hopeful.... And it worked!!!! (in case knowledgable readers are wondering, I had to omit the Idranet audio pair as I only wanted to use one of the 4-core cables - not an issue as I'm only putting a DTS on the end at the moment).

With the DTS in place, I re-jigged the Cortex layout to reflect the new locations and started to get the idea of "connections"

[img]http://jonwilkins.smugmug.com/photos/225370584-M.jpg[/img]
[i]new layout[/i]

[img]http://jonwilkins.smugmug.com/photos/225385007-M-0.jpg[/img]
[i]connections on the relay across the thermostat contracts[/i]

As with my first steps with Reflexes, whilst it's not always instantly obvious how to do things, after a few minutes it all drops into place and makes sense... then click click click click and different bits are configured together...

... now I just need to wire the relay outputs across the "call for heat" terminals in parallel with the existing stat....