ELK M1 & RCS TR-40 - How best to get ext temp?

[Sendero]

Seeing as both ELK and RCS make an exterior temp sensor, which one would I be better off going with? Should I get the ELK sensor and have it update the TR40 with the temp, or should I get the RCS version so that the TR40 is 'always' current and the ELK can poll it if/when necessary.

 

[gcimmino]

May be talking out of turn here, but I think the answer to your question depends on the capabilities of the M1, specifically the M1-XSP that will interface to the TR40.

You suggest two options:

Hook the RCS OS21 into the RCS system:

It's not clear to me that the M1 and XSP will let you "read" a RCS sensor's value. One can read a thermostat's current temp, but not sure if the OS21 will appear as an addressable 'stat to the XSP. If you could "pass through" commands from the M1 via the XSP to the RCS's 485 bus in the format the OS21 wants and get back the results, then that's another story.

Hook an M1 ZTS up to the Elk:

On the other side, if you had an Elk sensor, it's also not clear to me how you would send that info to the TR40. You can certainly read the Elk sensor's value, but not sure how you'd send it to the TR40 so it would display as the outside temp.

Anyway, I'm hoping someone who knows this better than I will enlighten us both!

I've asked Elk before about having the ability to pass through raw data over the XSP. I think this would be useful for things like programming thermostats remotely where you want/need to change a 'stat setting but don't want to roll a truck.

 

[Steve]

Disclaimer: I do not have an RCS stat or Elk sensors but this is my understanding of how it works from talking to others. I'm sure I will be corrected if I am wrong.

If you hook the remote probes to the TR40 they will show up on the TR40 as sensors and you can use them to averaging, etc, but the Elk can not see each individual probe, it will only get the main stat temp.

If you use the Elk sensors, you will have all the individual values and can do what you want in rules, etc, but the only way to display it on the TR40 is by sending it text messages, it will not show up as separate sensors on the TR40 display.

So I guess it really depends what your goals are as to how to set it up. The ideal would be for the Elk to be able to see each probe connected to the TR40 as a separate sensor.

 

[acdcelectric]

Unfortunately, even with Elk sensors, the M1 cannot perform direct comparisons between mutliple sensor values. You will have to write rules for actions based upon sensor values beiing "greater than" or 'less than". Depending on what you intend to do, this can take up a lot of rule space. Don't forget that if you use the "and" function you are using up an additional rule space as well.

In my new house, I have the M1 and a TRS 40 as well, but my TRS is controlled by the HAL software program, so neither controller can pass data back and forth, and the Hal cannot interpret sinsor inputs directly either. I have wiring in place for both an outside temp sensor and one up at the vaulted ceiling. As of now I have not yet integrated them into a complete energy management program. (I am still finishing the house for occupancy and have higher priorities for now).

If energy management is your goal here is where I left off planning:

I am thinking along the lines of having Elk detect the TRS output for heat demand (RH wire) as a contact closure (or possibly a voltage) in parallel with a relay output and then activate a loop that will check the value of the ceiling sensor. If it is 5 defrees warmer than the TRS, the Elk will activate the ceiling fans for say 2-5 minutes to blow the trapped heat back down before passing the RH voltage through the relay. If the heat demand goes away then the fans will shut back off and the output relay will never get energized. If the heat demand remains, the fans will remain on until the heat demand from the TRS is removed. Outside temp could also be integrated into the A/C demand cycle with a bypass damper.

I was discussing this with Martin over at AO and he has experience with multiple temp sensors and the Elk. Maybe he has some answers, or can direct you to another thread.

 

[acheslow]

Another thing to consider is that if you're using a PC-based controller integrated with your Elk you can probably get fairly accurate results from a web service. I'm using CQC to obtain the outside temperature from Weather.com and display that data along with the forecasted high and low for the day on my Elk keypads as custom text messages.

 

[bmil]

I brought this exact topic up before on the Elk forum when I wanted to do the same thing, i.e. outside temp.

Unfortunately the M1XSP, when it is configured to control a TRS-40, does not allow you to pass-through RCS commands. Therefore you can't retrieve the readings from an RCS temp. sensor connected to the TRS-40 and you can't send the TRS-40 an outside temp from an M1 temp. sensor.

Several people expressed a wish for this capability on the Elk forum at the time but there was no indication from Elk of any intention to provide such capability.

I have always wondered if the M1's native RS-485 format was compatible with the RCS RS-485 format. If it was, one might be able to configure the XSP as a serial interface, not a tstat interface, and just control the TRS-40 using pass-through RCS commands. Anybody know if their RS-485 formats are compatible?

 

[Sendero]

Since I have CQC, ELK, and the TR40 I should be able to do this right? I could use CQC to read an ELK sensor to get the temp (Or a web service) and then set ext the temp on the TR40, right?

 

[daxiang28]

I was wondering if anybody was able to figure out how to get the external temperature probe reading from the RCS to the Elk.

 

[sic0048]

If you use a third party automation software like CQC, you can write the value to the thermostat. For example, I use CQC and have a weather driver that "knows" the outside temp. I have a trigger that anytime the outside temp changes, CQC writes the new temp to the TR-40 thermostat. So the thermostat shows the correct outside temp on it's display even though there is not temp probe attached to the system.

I'd not sure there is a method that would allow the ELK to do this directly even today.

 

[tmbrown97]

I do similar to above, but I have the thermostats connected to my M1, not 3rd party software; however, I have Elve which connects to the Elk. I use Elve to get the outside temperature for my area and write it to a counter in the M1, then the M1 sends that via a direct ascii command to the thermostat every 10 minutes.

I know you can do direct ascii commands to/from the thermostat, but I doubt you'd be able to parse an incoming stream to get the temperature. If I get a chance when I'm back at the PC, I'll take a look.

 

[daxiang28]

Thanks Cocoonut. Hoping to feed temp without too much third party.

I do similar to above, but I have the thermostats connected to my M1, not 3rd party software; however, I have Elve which connects to the Elk. I use Elve to get the outside temperature for my area and write it to a counter in the M1, then the M1 sends that via a direct ascii command to the thermostat every 10 minutes.

I know you can do direct ascii commands to/from the thermostat, but I doubt you'd be able to parse an incoming stream to get the temperature. If I get a chance when I'm back at the PC, I'll take a look.

I have an RCS OS5... can you hook that straight into the elk zone instead of going into the rcs controller or do you need a more sophisticated ext temp probe to do that?

Steve

 

[tmbrown97]

Without hunting down the specs, I have no idea - but you could hook it up and see what it reads; worst case the value would just be way off. Remember temperature sensors only work on the 16 onboard zones, not on expansion zones. Of course you could also just order the Elk temperature probe - sure it's $100, but if it does exactly what you want in the simplest fashion, it may be the smartest option.

 

[daxiang28]

Without hunting down the specs, I have no idea - but you could hook it up and see what it reads; worst case the value would just be way off. Remember temperature sensors only work on the 16 onboard zones, not on expansion zones.

Gave it a shot and it looks like the voltage it reads is the Celcius equivalent. I tried setting the zone (zone 15) as a temperature zone, but it didn't seem to recognize it as a legit temperature probe. Wonder if I could use the voltage value and convert it to Fahrenheit or something?

Steve

 

[jml]

I decided to put our 2-zone home under the complete control of M1 rules. I have three layers of logic, (Armed Away, Armed Stay/Not Armed), (Winter/Summer - which is effectively a temperature check outdoors with keypad temps at the doors), (Morning, Day, Night). The combination of all these different states results in a ton of rules, but it allows my home to be more adaptive and energy efficient. I pulled out all the set-points for various states and breakpoints into custom variables (wish there were more).

 

[wuench]

I decided to put our 2-zone home under the complete control of M1 rules. I have three layers of logic, (Armed Away, Armed Stay/Not Armed), (Winter/Summer - which is effectively a temperature check outdoors with keypad temps at the doors), (Morning, Day, Night). The combination of all these different states results in a ton of rules, but it allows my home to be more adaptive and energy efficient. I pulled out all the set-points for various states and breakpoints into custom variables (wish there were more).

Would you mind posting your rules? I currently let the M1 handle set points but the constant weather changes in St. Louis this time of year (90 degrees one day, freezing temps the next) have me thinking about doing something more complicated.