Light Automation

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  • JonS
    Automated Home Guru
    • Dec 2007
    • 202

    Light Automation

    As Karam said in a recent post light automation is not that easy in all cases. Perhaps someone can help with my kitchen light problem ...

    The kitchen has two sources of natural light, a window at the side of the house about 1.5m from a fence and then through a double doorway into another room which has excellent natural light.

    I have automated this in two ways (at different times)
    1) internal light sensor (MFP near door) and external light sensor
    problems; if I set the external sensor to optimise kitchen light the lights in other rooms come on inappropriately early as they get more natural light than the kitchen.
    2) Internal light from MFP and manual threshold set on external ight meter.
    Pro; most lights in house OK
    Con: sometimes "oscillatory" kitchen light behaviour as the manual threshold get triggered / untriggered changing the current over-ride mode.

    One observation I have is that while there is historesis for an analogue level in the set-up there is no temporal element to this. So someone walking past a light meter on an MFP or wall plate briefly but substantially interrupting the light level can trigger a threshold, a damped temporal response would help here without I think affecting the other behaviours (at least for lights). This would help in several rooms where entering the room briefly shades the light meter and causes the light to switch on uncessarily. Does anyone know if this is user editable?

    It would also help if it were possible to set multiple thresholds (on the outside light meter), maybe I need a more sophisticated control than light on/off to prevent strage interactions with the override state - any ideas??? OR to be able to set the thresholds within the connections options....

    Other ideas on how to improve light automation much appreciated. In some rooms we very rarely use the switches, in others it is all too often!

    TIA
    Jon

    Jon
    JonS
  • Karam
    Automated Home Legend
    • Mar 2005
    • 863

    #2
    I'm not so clear on the setup - is it that you don't have an internal light level sensor in the room adjacent to the kitchen so you are using external light level to control these, and also why using external light level to control lights in the kitchen (which I'm understanding has an internal sensor) ?

    Regarding the 'temporal' filter on light level, indeed there is such a thing at the module level and on some modules this is mostly implemented using a first order discrete time filter. In such modules the filter pole (time constant) can be adjusted albeit with a crude non linear resolution. The default setting is not at a limit so further slowing down of response is possible. Let me know which type of module and I can advise further.

    Comment

    • JonS
      Automated Home Guru
      • Dec 2007
      • 202

      #3
      The set-up is kitchen light connected to kitchen light sensor in MFP and external light meter, to which I had added some manual thresholds.
      The adjacent room has its own MFP.

      Since posting I have had a re-think and have removed the external meter and adjusted the "very bright threshold" to be just above the level that the artificial lights can deliver. This is actually working much better. However I do still have the "temporal issue" e.g. this morning using the intercom as I approached the MFP and pressed the button the lights flicked on! When I walked away they stayed on as the natural ight was not sufficient to exceed the vbrght level.

      I also have LPS with the same issue (walk past and the light flicks on, and for competeness an LTH (external). What other impacts is a change to the time filter likely t have?
      Thanks
      Jon
      JonS

      Comment

      • Karam
        Automated Home Legend
        • Mar 2005
        • 863

        #4
        Light sensor dynamic filter adjustment

        MFPs and some other nodules with light sensor function will allow adjustment of the dynamic filter using the following typical direct command packet:

        FA90xxyy4400120807pp

        where xxyy is the Node ID and pp is the 1 byte hexadecimal filter parameter.

        The default value for pp is typically DC (220d). The higher the value the slower the response. It is very non linear so you'll probably find that you will only start to notice significant slowing in the range F0-FF.

        I'd suggest you play around with the different values whilst the network is running so that you can observe the effects. Once you are satisfied with a result you can save the value to the module EEprom so that it stays in force after a reset. To perform the save I'd strongly recommend that you first stop the network, reset the module, send the direct command to alter the filter parameter to the value that you desire, then issue the direct command to save module parameters which is of the form:

        FA90xxyy440008

        Then you can restart the network.

        I'm afraid its a bit pot luck which modules will respond to the dynamic filter adjustment command, since some older variants did not have the feature at all and I'm also aware that some of the newer updateable modules have only recently had firmware changes to implement the command. MFPs should be ok though. If you try and it doesn't work on a particular unit let me know and we may be able to resolve.

        Comment

        • Kevin
          Moderator
          • Jan 2004
          • 558

          #5
          Originally posted by JonS View Post

          It would also help if it were possible to set multiple thresholds (on the outside light meter),
          Jon
          I found this same need - particularly in relation to internal rooms that start getting darker earlier than others, and of course outside lights need to come on much later. In the end I duplicated the object with different levels set - but having an ability to set multiple levels would be tidier.

          I played around with another object that allowed thresholds to be added but the behaviour of these at the time seemed different to my needs. I'm sorry this last bit sounds a bit vague but I can't remember the exact details and I don't have Cortex installed currently - (HD failure) - but will be re-installing it again on a silent rackmount machine that I am still awaiting the arrival of.

          Kevin

          Comment

          • JonS
            Automated Home Guru
            • Dec 2007
            • 202

            #6
            Karam, thanks for the detailed commands, I will find a quiet time to experiment sometime over the summer, and certainly before I start changing the eeprom.
            Will this change affect the response of all the sensors in a module (e.g. PIR)?

            Kevin, I had not through of adding multiple light objects to the same sensor - I take it this works OK or are there some issues to consider in this approach?

            Jon
            JonS

            Comment

            • Karam
              Automated Home Legend
              • Mar 2005
              • 863

              #7
              The light level filter is for for the light level sensor only. There is a separate adjustuble parameter (dwell period) for the PIR sensor which controls how long the PIR signal remains ON after a motion detect (assuming no further motion). Typically the dwell period is set to 1s and its unlikely that adjustment would be required in most applications.

              Regarding different thresholds from one light level sensor, obviously its possible to set multiple thresholds to do whatever you like if using the sensor in a more traditional control context eg. upon each threshold trigger a different event (see the light level sensor behaviour menu and the graph icon at the bottom) but this is different to setting multiple thresholds in the integrated lighting automation context. In the latter case the light objects simply receive a logic signal from the connected light sensor telling them whether its dark or not (ie. one set of thresholds from one senor) and then combine this with other information such as presence, time of day and so on to determine whether to switch on or not.

              Though I guess our concept is that internal lights would predominantly be controlled by adequately positioned internal sensors, I can understand the desire to have multiple thresholds from one sensor (eg. outside sensor) within the integrating lighting automation. For us to introduce this I'm guessing would require a substantial change to the relevant Cortex internal structures so not something to be done without further consideration and some time.

              I'm not entirely clear on what Kevin has done - I can only think that this must be related to using xAP light level sensor objects?

              Comment

              • Kevin
                Moderator
                • Jan 2004
                • 558

                #8
                Originally posted by Karam View Post
                I'm not entirely clear on what Kevin has done - I can only think that this must be related to using xAP light level sensor objects?
                In a way it is as it was a change introduced to support xAP light level devices but I don't think you actually need the xAP Automation object option to do this.

                Create a 'virtual' network object (ALS) and make a connection from its 'alternative light level source' back to your existing 'light level' output from the real sensor. You shouldn't network enable the newly added ALS as it basically acts as a duplicate of the original, but conveniently you can set different levels. These 'alternative' inputs appear now in a few network objects, to allow you to associate them with a xAP device if needed.

                Do be a little careful if you create default connections though as you'll have different dark outputs from each sensor.

                K
                Last edited by Kevin; 4 August 2008, 05:10 PM.

                Comment

                • chris_j_hunter
                  Automated Home Legend
                  • Dec 2007
                  • 1713

                  #9
                  no answer, I'm afraid, but this makes me wonder how many light-sensors Idratek can cope-with - ie: an obvious way to avoid problem from people walking-by individual sensors, is to have lots of them ... well, more than a few ...

                  we're intending having our MFPs in places convenient for using the intercom aspect, which might not be best-placed for the various sensors ... although, on reflection, maybe that's wrong ... having all sensors close to where people actually are, can't (surely) be bad ...

                  actually, it's tricky ... people expect immediate response, when they need it, but get annoyed when the response is inappropriate !

                  hmmm ...
                  Our self-build - going further with HA...

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