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Installation Planning

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    Installation Planning

    I am in the process of planning the setup of my new house which is currently under construction and would like to get some advice... I have looked around on the message board and have not seen recent recommendations so I thought I would post this.

    I have spent several weeks reading up on and playing with 1-wire technology. I have decided that I would like to install temperature and weather instruments.

    My plans are to use HomeSeer, MCSTemperature, and MainLobby.
    Going through my floor plan I have decided to put in temperature probes throughout the house, Rain Gauge, AAG weather station, measure water/gas/electric useage, and various contact sensors. These would all be connected on the 1-wire network back to HomeSeer.

    After looking at everything I would like to do I am concerned that I may set this up incorrectly.
    Here is what I have so far;
    37 Temperature Probes
    AAG Weather Station
    Rain Guage
    2 Humidity Sensors
    2 Barometer Sensors
    1 Solar
    1 Lightning Sensor
    6 Counters for various Gas/Water/Electric meters
    10 NC Sensors for various doors/sensors

    I have purchased the software and the majority of these devices and have connected them in my work area. I have them connected through the USB DS9490 and talking to HS through MCSTemperature.

    As you can see the number of devices are getting large and during polling intervals it starts to drag my system down not to mention I have not even connected up all the sensors.

    Since I have so many sensors I don't think they will actually fit in one copy of MCSTemperature.
    1. Is there a way to have multiple copies of MCSTemperature running and reporting to one copy of HS?
    2. Is there a limit as to how many devices I can have connected to one DS9490?
    3. Should I use something other than the DS9490 or mix it with a Temp08?
    4. Can I have multiple DS9490's on one PC reporting into HS?
    5. In my new house I had planned (in most cases) to just run Cat5e to each individual sensor and then connect up the runs in my wiring closet. Not sure if this is the best way.
    I guess at this point I know what I would like to do but am not sure how to get the architecture in place to make this happen. Any advice would be appreciated.


    When you have a large number of sensors or run your polling rate on the faster side then you want to look at ways to share the processing burden. For the generic sensors, which include most of what you have itemized, the Temp08 will be a good choice to offload the PC's CPU. You can run both interfaces to the PC.

    Preinstall planning is difficult with 1-wire because there is some degree of art to it. The homerun wiring for a LAN, Video, or Telco is the least desirable topology for 1-Wire. 1-Wire is best done with a daisy chain. When the devices are mounted directly on the daisy chain then you can get 100's on the same wire. When you start adding pigtails then the max count goes down dramatically. When you start adding branches then the probability of getting any device working decreases rapidly.

    There can be only one interface per 1-wire cable. If you want to split between the load between a DS9490 and Temp08 then you need to run 2 lines. You could add a second DS9490 and run three lines. The reason you would run the second DS9490 is not because of CPU burden, but because of the wiring topology. Your chance of success in a non-ideal wiring setup is greater with two lines of 10 sensors each than 1 line of 2 sensors.

    I've experimented with a number of techniques to get reliable and maintainable 1-wire operation. I started with the prewired homerun from each room to a central panel and added a daisychain for outside weather instruments and other speciality devices. I then tied them all together with various branching techniques to a single Temp05. It did not work so I split off and ran multiple DS9097U and the Temp05. As I added more sensors to the network later I disturbed the balance and needed to cast a spell to get it working again.

    The configuration that I'm happy with now uses a 1-wire hub. This allows me to add branches or add sensors to a single branch without disturbing what is working well on all other branches. The hub provides the mechanism to run the wires in a homerun fashion and interrface them reliabily to a DS9490/DS9097U.

    The same concept could be used with the Temp08, but the Temp08 does not know how to manage the hub. xapmcs1Wire is the only HA software that I'm aware that will deal with the hub.

    My recommendation is to prewire zones of the house to a central location. This would be very much like an electrician does when wiring the 120 to a small circuit breaker. Run the wire within a zone in a daisychain fashion with adequate slack provided to the sensor can be mounted to the main line rather than a pigtail to the main line. Leave slack also for potential growth areas. It is better to add 20 ft to the daisy chain that to add a 10 ft "T" off the main line.

    Try to organize it so the Temp08 can pick up the load for anything you want to run at a higher polling rate. I run my entire 1-wire at 6 minute intervals.

    If you are using 1-wire for discrete input then there is a big difference in recognition time when running them with the Temp08 based upon the wiring. You will want to run power to all the sensors if this is the case. Contact Mitch at Midon Design to get the specifics.

    You can try to connect wires from your central point to one or more DS9490s or you can connect with the hub. You can add multiple Temp08 if the need arises. You can add multiple DS9490s if the need arises. mcsTemperature will support 1 Temp08 and multiple DS9490s. I believe Jim Doolittle has software that will support multiple Temp08. xapmcsTemp0x will support an unlimited number of Temp08. xapmcs1Wire will support an unlimited number of DS9490 or DS9097U interfaces. I use the hub from Eric at


      Michael, thanks for the response.
      Based on what you have written and what I have seen from other posts this is what I will probably do;

      Attached to one PC running HS with MCSTemperature I will split up my 1-wire network into multiple "segments". Each segment will be connected to the pc through seperate Temp08(s) and DS9490's. It really looks like I will have to "play" with each segment to really see how many devices I can get on each. For each of the 9490 segments I will use a 6 Channel hub to increase my chances of getting additional daisy chains on the segment and keep noise from spilling over to each branch.
      Example (Hope this makes sense):
      • PC
        • Temp08 - (Segment01)
          • Daisy Chained Segment
        • DS9490 - (Segment02)...
          • 6-channel Hub
            • Channel 1 Daisy Chained (branch01)
              • Temperature Sensor xx
              • Temperature Sensor xx
              • Temperature Sensor xx

              • Temperature Sensor xx

              • .....

            • Channel 2 Daisy Chained (branch02)

              • Temperature Sensor xx

              • Temperature Sensor xx
              • Temperature Sensor xx
              • Temperature Sensor xx
              • .....
            • .....
      So if this is the right architecture to pursue could you recommend what you would put on the Temp08 vs. the 9490's? You mentioned putting devices you want to pole more often on the Temp08. At this point I am not even sure which devices I would poll more often. I would think that Temperature, Barometer, Humidity, Solar, and Rain would poll less than say Water/electric/gas, wind, and polling swithces would be more often?

      I also noticed that the I might be limited to the number of Analog devices in MCSTemperature? Looks like 13x4 is my limit?



        This architecture looks just like my current one and I think it is a good choice.
        The Temp08 gives you low-burden data collection while the DS9097U gives you flexibiltiy in sensor technology. Most of what you know about today will be supported by the Temp08 and you may want to consider a wiring architecture that will support more than one of these. i.e. a hub branch morphs into a Temp08.

        Also consider where the ends of each of you branches are terminated. You may find a desire to connect two branches to make one longer branch. If your branch ends have a way of being connected then this option is open to you. Sometimes it makes sense and sometimes it does not.

        Temp08 has a 60 second minimum update cycle. If memory serves me that should get you to around 35 sensors running continuously. You should be able to get about this many sensors on a Temp08 run if they are mounted correctly. It is OK to run the Temp08 flat out, but if you do the same with the DS9490 then you will see the PC being sluggish to user inputs.

        I think for most of what you will be doing a 5 to 10 minute interval will be adequate. The software that supports the hub has no provisions for different rates for different hub branches. When you have discrete inputs on hub branches then the recognition of the switch will be slow. You need a setup specifically geared to fast switch response. My software is not optimized for this capability through a hub.

        I've been using a browser-based variant of mcsTemperature for more than a year now. It changes as I want it to interact differently with my distributed architecture. I will eventually finish it off. It has no limit on sensor count that now exists in mcsTemperature.