New dual band devices and AP’s, possible problem?

[TJF1960]

I know the discussion of having too many or not enough AP’s causing problems in an installation has been discussed here before. But it seems no real definitive answers have ever been agreed upon which I fully understand because each installation is different. Now with the new dual band devices starting to come out the average installation could have the equivalent of 5, 10 or 20 AP’s depending on what the user installs.

 

I purchased a couple of the new dual band dimmers which by the way work great and are a lot smaller and IMHO look nicer. I also have a couple of motion sensors in two adjacent rooms, the one room farthest from the one AP has had intermittent operation because of the distance. So I added the dual band dimmer in that room which has solved the intermittent ms problem in that room. However now the other room ms, which up to this point has worked flawlessly, now is intermittent. I haven’t dug into troubleshooting it yet but it has led me to wonder if 2 dual bands or AP’s are on the same leg of the power panel and they both receive the same transmission from a rf device, then both dual bands or AP’s will rebroadcast the data both thru the power line and via RF (as I understand it). If the two devices are transmitting at the same time will one detect incoming data and pause its transmission? Or do they all transmit without regard to each other? (my questions pertain to both power line and RF transmissions).

 

Tim

[IndyMike]

Hello Tim,

 

I have some partial answers as well as questions of my own.

 

I'm a bit surprised that you have a range issue with a MS in an adjacent room. I have 1 AP located centrally in my house (1st floor). I can communicate with it from both the second floor an basement (4500 sq foot - roughly 75' line of sight distance). Are you having problems with this device turning on the linked loads, or are you getting an ISY message that it has a problem communicating with the device?

 

Other than having periodic problems with the AP going "off line" when the central vac power head is plugged in the same outlet (kids), I do see infrequent communication errors. I attribute these to a 900 Mhz phone in the same room. A bit more on this later...

 

In response to your question regarding destructive powerline interference (more than one RF receiver). This was very true with X10. I have not seen evidence of this with Insteon. From the "white paper":

 

RF/Powerline Synchronization

INSTEON RF devices attached to the powerline use the zero crossing for message synchronization. These devices receive INSTEON messages synchronously on the powerline, synchronously via RF from RF Repeaters, or possibly asynchronously via RF from mobile RF devices.

 

Messages that need to be retransmitted will have a Hops Left count greater than zero. If the INSTEON device receives such a message from the powerline, it will first retransmit the message using RF as soon as it has received the last packet of the powerline message, then it will retransmit the message on the powerline in the next timeslot. If the device receives the message via RF, it will first retransmit the message on the powerline in the next timeslot, then it will retransmit the message using RF immediately after sending the last packet of the powerline message. In this way, RF message received asynchronously will be resynchronized to the powerline zero crossing at the earliest opportunity.

 

Per the white paper, multiple RF receivers putting information on the powerline should not be a problem. They are all synchronized to the zero crossing. All of the Insteon devices effectively use the same zero crossing to synchronize repeated commands.

 

Now for my questions -

 

1)What happens when a local load or noise source affects the powerline zero crossing. This is a rhetorical question. If an Insteon device is in the vicinity, it will transmit at the wrong time.

 

2)The Insteon protocol indicates that devices follow group messages with group cleanup commands. I have never seen a group cleanup command from a motion sensor. Nonetheless, the ISY somehow knows that there is a problem with communication to a motion sensor. I'm assuming that this is because the ISY is attempting to reply to the MS and is unsuccessful. I see this as far more of an issue with multiple RF transmitters - all trying to communicate with the same MS at the same time.

 

in reading over the above, I realize that this is one of my typical responses:

1) Really don't answer the OP's questions.

2) Raise more of my own.

 

Sorry,

IM

[TJF1960]

Hi IndyMike,

 

Thank you for taking the time to reply.

 

Unfortunately it is a hit or miss when the light turns on or off based on the ms. As such when the light doesn’t turn on it is usually at a time when I cannot attempt troubleshooting.

 

I'm a bit surprised that you have a range issue with a MS in an adjacent room. I have 1 AP located centrally in my house (1st floor). I can communicate with it from both the second floor an basement (4500 sq foot - roughly 75' line of sight distance). Are you having problems with this device turning on the linked loads, or are you getting an ISY message that it has a problem communicating with the device?

I had originally based my assumption that it was a range issue because when the ms in the furthest room from one of the AP’s was tripped it would turn a SL light on 99.9% of the time however maybe 30 to 40% of the time the ms LED would rapid fire when it didn’t receive acknowledgement. I replaced the batteries to make sure it wasn’t the low battery indication, as well as swapped the ms out with a new one. The problem continued. But when I moved the AP closer to that room the ms stopped rapid firing the LED’s upon tripping.

As a side note, I always though it strange that the ms would always be able to turn the light on and off but that it was just the ack. It never received.

In any case when the new dual band dimmers came out I thought I could kill two birds with one stone so I replaced a plug in dimmer with the new DB dimmer in that room. Since then I haven’t seen that ms rapid fire its LED, and it has been 100% responsive. However the next room which previously had worked flawlessly is now at 80-90%. There are times when the ms in that room will not turn on the SL light. Which led me to my original post.

 

2)The Insteon protocol indicates that devices follow group messages with group cleanup commands. I have never seen a group cleanup command from a motion sensor. Nonetheless, the ISY somehow knows that there is a problem with communication to a motion sensor. I'm assuming that this is because the ISY is attempting to reply to the MS and is unsuccessful. I see this as far more of an issue with multiple RF transmitters - all trying to communicate with the same MS at the same time.

Is your concern with the propagation delay from multiple AP’s or DB devices transmitting at the same time to the ms but from multiple varying distances? In other words an AP and DB transmit the data back to the ms at the same time but because of the distance difference between them one transmission reaches the ms slightly sooner than the other transmission resulting in what looks like noise to the ms?

 

Tim

[IndyMike]

Hello Tim,

 

I just realized that you had posted in the Smarthome section of the forum. As such, you're probably looking for information from the manufacturer rather than my conjecture and paper napkin calculations.

 

Sorry to have jumped in and sidetracked your search for information. I hope Smarthome replies as well. I do not understand nearly enough about the function of the AP's. I would very much like to learn more.

 

IM