I spoke with Ray last week and it appears the OS 3.0 is limited to 72 zones regardless of those zones being remote or hardwired to the controller. That said he mentioned someone else modifying the firmware for OSPi and running something like 180 zones, via remote zones/controllers. So the new plan for POC A & B is to use use a OSPi for the master controller and OS 3.0 controllers for the in-cabinet zone control. For instance:
OS Pi as master controller A1 (POC A Master Valve and POC A Flow Meter)
OS 3.0 as remote controller A2 (72 zones)
OS 3.0 as remote controller A3 (22 zones)
OS Pi as master controller B1 (POC B Master Valve and POC B Flow Meter)
OS 3.0 as remote controller B2 (72 remote zones)
OS 3.0 as remote controller B3 (50 remote zones)
OS 3.0 as master controller C1 (POC C Master Valve and POC C Flow Meter)
OS 3.0 as remote controller C2 (45 remote zones)
OS 3.0 as master controller D1 (POC D Master Valve and POC D Flow Meter)
OS 3.0 as remote controller D2 (37 remote zones)
Ray said he’ll likely modify the firmware so that OSPi controllers are able to utilize more than 72 total zones, as the Pi controllers aren’t as limited in ram, CPU, and onboard program storage. It sounds like controlling more than 72 zones might technically be possible with the 3.0 controllers but the need to do so is so rare that it doesn’t make sense to go through the very time consuming work of fully validating the ability. Basically the 3.0 controller has a limit to the number of zones it can control before it runs out of ram, CPU cycles, and/or storage, we just don’t know where that limit is. For our needs the OSPi controller should be just fine as a master controller.
I also asked Ray about the issue people are having with the new weather source data causing run times to be adjusted based on the current temperature instead of the normal Zimmerman method and he said he is aware of the issue. We didn’t go into detail but it sounds like one of the reasons for the mis-adjustment is due to inconsistent data formatting of the received weather information. From experience I know that engineers are extremely reluctant to promise a timeframe for a fix when they don’t know how much time and effort will be required. That said, I would think that this issue is near the top of the priority pile and is likely to be fixed in the coming weeks, not months.
The remaining question is if we can setup OS to monitor flow meter data and create an alarm/event/notification if the flow rate goes outside a predetermined range. For instance, if the normal flow rate for zone 2 is between 8 and 12 gallons per minute, and zone 2 is instead receiving 40 gpm, it would be ideal if we could then skip that zone and send a notification (email, text, etc.) so that we can send someone to figure out what’s going on and make the repair. I’d be interested to know if anyone has implemented any kind of leak detection with their OS.