Using PLEG with the Secure SRT321 & SSR303 Stat & Relay (old Horstmann)

Plugins & Plugin Development Program Logic (PLEG)
1

Hi, hoping someone might have a few ideas on an issue I have setting up the above Secure Thermostat and Relay devices via Vera using PLEG.

I had originally paired these devices as per guides I found online but found the connection between them to be unreliable (distance likely a problem).

Instead, I have added them both individually with to my Vera Lite (UI5) and put together a PLEG to control them. This seems to get rid of the distance problem and both keep constant connection to Vera.

The issue I have is when I run an overnight scene to keep the bedroom temps at say 20 degrees, the scene works for a while at the start but then the relay stops supplying heat. The thermostat will be set at 20 degrees and the room will be at 18, so the stat is calling for heat, but the relay is off. I need the stat to persist throughout the night, so that when the heat level is reached the relay powers off and when it gets cold, the relay powers on.

One possibility I read is that the relay stays on for a preset amount of time and if it does not get an update it shuts off again for safety. When the two were paired this was not a problem as they constantly communicated, but now they are seperately connected to Vera, this might be an issue.

Does anyone know how I can program with PLEG to persist the set point temperature/keep updating the relay to ensure the rooms don’t get cold at night or find out from the logs what is going wrong? My setup is below for those that might know.

Thanks in advance! PS PLEG is great!!

  1. In the inputs, I added the following two device inputs to read the Current Temp and Current Set Point from the thermostat:
    Name Device Name Device Variable Current Value
    pUpTstatCT1 Heat: Thstat Upstrs CurrentTemperature 18
    pUpTstatSP1 Heat: Thstat Upstrs CurrentSetpoint 20

2)I added the following conditions:
cUpTempLow = pUpTstatCT1=pUpTstatSP1

3)I added actions
cUpTempHigh Immediate - 1 (Relay to turn heat off)
cUpTempLow Immediate - 1 (Relay to turn heat on)

4)I created a scene in Vera called “Heat Overnight” that sets the set point on the stat to 20 degrees which is scheduled to start at 8pm.

2

Here is how I do it:

Schedules
I30M OnType: Interval, 30:00 OffType: None

Device Properties
RelayMode RelayName ModeTarget

Conditions
RelayPulse [Repeat=Yes] I30M

Actions
RelayPulse RelayName SetModeTarget NewModeTarget={(RelayMode)}

This resends the last command every 30 minutes so the relay stays alive.

3

Thanks so much for the help - I have put together the setup as you suggested so hopefully tonight will be a warmer one than the last few!

On the last part you mentioned, do I need to exactly type “={(RelayMode)}” into the advanced tab of the action part where I have selected the relay and SetModeTarget?

4
On the last part you mentioned, do I need to exactly type "={(RelayMode)}" into the advanced tab of the action part where I have selected the relay and SetModeTarget?

Enter {(RelayMode)} in the text box to the right of the label NewModeTarget.

5

This worked perfectly - thanks for the help :slight_smile:

6

Hi,

Sorry for reviving an old thread. I have used the 30 minute repeating logic which works when I use the webUI or app etc to switch on my heating BUT if I manually press on/off on the panel of the secure heating valve the status is not changed on either the UI or of course PLEG… I cant remember this happening before. What happens then is the heating only remembers the last device change triggered remotely and repeats this regardless whether the state is true or not… so the heating can knock itself off/on incorrectly.

Is this normal?

John

Edit I have solved this with help from Ricahrd, the post above states you should monitor modetarget but it should be modestatus… once the heating polls it updates.