Can you be too close to the PLM

[brausse]

I moved an ApplianceLinc V4.2 to a new plugin and when it's in that plug, it can't be queried. I can turn the device on/off but the ISY status never changes and if I query it, it never responds to the status request. If I move it to any other plug, it works just fine. One thing to note is that the PLM is plugged into a plugin on the other side of the wall so the PLM and ApplianceLinc are only seperated by about 1 foot of electical wire. Is this too close to the PLM?

[Brian H]

Have you verified both outlets are on the same branch circuit?

Close to each other does not mean that are always connected to the same circuit.

Strange set of findings. On and Off OK but status not.

[brausse]

I know they are one the same circuit and connected by 1 foot of wire because I did the wiring. I agree, seems strange that on/off works but status doesn't.

[ELA]

Hello Brausse,

 

Since you are sure they are on the same circuit, you might try using an extension cord to plug in the appliancelinc to the same outlet and see if it performs better.

I have several devices in my home within 1 foot of each other and have done tons of testing with devices within 1 -2ft of each other without ever experiencing what you are seeing.

 

Might pay to record your results via the level 3 communications screen in each case to get a better idea of what might be happening.

[brausse]

I don't have problems with 2 devices close together, it's a ApplianceLinc right next to the PLM. When I do a level 3 trace, I see the request for sense sent out but no reply from the ApplianceLink. If I move it to another plug, I get both the command and reply logged.

[ELA]

The PLM is a device.

 

Record a level 3 trace from the outlet that the appliancelinc does work on ( and post it please). Then use an extension cord to the appliancelinc on the outlet that it previously did not work on and record a level 3 trace.

[oberkc]

Is this too close to the PLM?

 

Like others, I have devices on the same outlet as the PLM. No problems experienced here.

[ELA]

Brausse,

 

I often do testing on a bench top with only a PLM and another device. These two devices are then isolated from the power distribution system using a Filterlinc. This produces a large amplitude PLM signal.

At one point I was experiencing some issues that lead me to question if there can be such a thing as too large of an Insteon signal amplitude. My interest at the time was mostly theoretical in nature.

It is for that reason that your post caught my attention.

 

The most informative method to diagnose such an issue is with an Oscilloscope. Since most people do not have access to one , I was attempting to suggest some tests that might help you understand the issue.

 

If the signal strength was too large then adding an extension cord between the devices will insert some level of attenuation. If a cord of sufficient length is added and communications begins to work again that would be very telling.

 

I suspect there is something else involved but am not intending to ignore any possibility.

If you use the level 3 event viewer you can use the number of hops used as a gauge as to how well devices are communicating ( if there is any response at all).

I was curious to see how well the devices are communicating when the APL is in the "good" location as a baseline.

 

 

Does the "bad" outlet ( one where APL does not communicate) have anything else plugged into it?

I sometimes tend to look for the most complicated answer to a problem and forget to look at the more obvious. Thus, have you confirmed the 60HZ AC voltage level at the outlet in question?

[brausse]

First off, here's the traces, first one, with the APL in the plugin right behind the PLM, second one with APL in a kitchen plugin. In both cases, the APL turns on and off with commands but in case 1, the status doesn't change.

1)

Mon 10/15/2012 10:08:38 AM : [iNST-TX-I1 ] 02 62 1D AB 90 0F 11 FF

Mon 10/15/2012 10:08:38 AM : [iNST-ACK ] 02 62 1D.AB.90 0F 11 FF 06 LTONRR (FF)

Mon 10/15/2012 10:09:09 AM : [iNST-TX-I1 ] 02 62 1D AB 90 0F 13 00

Mon 10/15/2012 10:09:09 AM : [iNST-ACK ] 02 62 1D.AB.90 0F 13 00 06 LTOFFRR(00)

 

2)

Mon 10/15/2012 10:14:26 AM : [iNST-TX-I1 ] 02 62 1D AB 90 0F 11 FF

Mon 10/15/2012 10:14:26 AM : [iNST-ACK ] 02 62 1D.AB.90 0F 11 FF 06 LTONRR (FF)

Mon 10/15/2012 10:14:26 AM : [iNST-SRX ] 02 50 1D.AB.90 1B.FD.4D 2B 11 FF LTONRR (FF)

Mon 10/15/2012 10:14:26 AM : [standard-Direct Ack][1D.AB.90-->ISY/PLM Group=0] Max Hops=3, Hops Left=2

Mon 10/15/2012 10:14:26 AM : [ 1D AB 90 1] ST 255

Mon 10/15/2012 10:14:38 AM : [iNST-TX-I1 ] 02 62 1D AB 90 0F 13 00

Mon 10/15/2012 10:14:38 AM : [iNST-ACK ] 02 62 1D.AB.90 0F 13 00 06 LTOFFRR(00)

Mon 10/15/2012 10:14:38 AM : [iNST-SRX ] 02 50 1D.AB.90 1B.FD.4D 2B 13 00 LTOFFRR(00)

Mon 10/15/2012 10:14:38 AM : [standard-Direct Ack][1D.AB.90-->ISY/PLM Group=0] Max Hops=3, Hops Left=2

Mon 10/15/2012 10:14:38 AM : [ 1D AB 90 1] ST 0

 

Now, I read ELA's reply and because I have an oscilloscope, I put it on the failing plug (where the APL is plugged into) and noticed a strange noise at the zero crossing when there was no X10 or insteon activity. The plug on the opposite side of the wall from the APL has the PLM and a UPS plugged into it and plugged into the UPS is my ISY994IR/Pro and an internet camera, both plugged into the battery backup side of the UPS. When I unplugged the internet camera from the UPS, the APL started working properly. I was under the impression that everything on the battery backup side of a UPS was isolated from the mains side but I guess not. I'll just have to find another place for my internet camera and move it there. Thanks to all for the help.

[Brian H]

Many model UPS units can cause power line signal problems; noise or signal absorption. As its power line input filters. filter the X10 and Insteon power line signals as noise.

 

Is the UPS on a filter designed for X10 or Insteon signal conditioning?

Mine is on a 10 amp FilterLinc and its pass through outlet has my PLM in it.

[brausse]

No, the UPS is not on a filter and my UPS does not have a passthru plug. One side is battery backed up and the other side is surge protected. I've had the UPS in the same place for a long time and haven't had problems until I put a APL in the room behind it. The camera then somehow interferes with the APL status reporting but nothing else. It's very strange that with the camera plugged into the UPS battery backup plug, I can turn the APL on and off with a 0% failure rate but the status/query has a 100% failure rate. I'd have thought that if there were problems with communication, that the on/off commands would also fail. Anyway, I moved the camera to a UPS in the basement and things work just fine now with the APL in the "bad" plug. Thanks for the help and comments.

[LeeG]

None of the messages from the ApplianceLinc (02 50 messages) are making it back to the PLM. Even though the ApplianceLinc received the On/Off commands the ACKs did not come back. That is consistent with the lack of response to the Query. Nothing from the ApplianceLinc makes if back.

[brausse]

I know the replies aren't getting back but why? If the on/off commands are 100% reliable, why do the replies and query commands fail 100% of the time?

[oberkc]

I'll just have to find another place for my internet camera and move it there.

 

If you have confirmed that the UPS, or devices plugged into the UPS, cause problems, I think it would be better to filter those problem devices, rather than find another place and hope they are less problematic there. You are, in my mind, simply postponing problems, rather than solving them.

[Brian H]

Sorry if I was not clear. The pass through outlet I mentioned is on the FilterLinc not the UPS.

The UPS is connected to the filtered outlet and the unfiltered outlet has my PLM in it.

 

That noise pulse near Zero Crossing is right in the middle of the Insteon message slot.

Maybe effecting how the APL was trying to respond.

[ELA]

Glad to hear you have had some success Brausse,

 

Since you have access to a scope do you also have a filter to remove ( or attenuate) the 60hz content? If so this allows you to measure the Insteon signal amplitudes and can be an invaluable tool in troubleshooting these kinds of issues.

 

From your description ( and LeeGs comments) it sounds like signals make it from the PLM to the APL but not so much from the APL to the PLM in return.

Every Insteon device has slightly different transmit amplitudes and receive sensitivities. It is not uncommon for signals to be successful in one direction and not the other.

 

If you have the capability to measure the signal amplitude try measuring the signal amplitude with the UPS

connected and unconnected. I suspect you will see a very large signal amplitude difference.

... Or as others have said just add a filterlinc to the UPS input.

While there may, or may not be, a noise issue you almost certainly have a signal suck issue with the UPS.

The filterlinc is a good device to help both.

 

I recently did a test on a APC back-ups XS1000. It was the worst signal sucker I have tested to date.

Just so happens that at that time I also did a test using an APL and a PLM communicating over 2 ft of cable in an isolated network. Of course they communicated fine together. I then connected the UPS input to that network and all communications then failed miserably. ( this even though the PLM signal level was still at 1.8V p-p !!)

For the most part smaller signal suckers will usually only reduce the signal amplitude with little distortion. A larger signal sucker/noise maker like the UPS in my test ( and possibly yours also) will also distort ( or phase shift) the Insteon signal severely enough that communications fail. As stated earlier, even though the signal amplitude is still appreciable at 1.8V p-p.

[brausse]

Thanks everyone. I'm going to order some filterlincs and install them on my APC UPS devices (3).

 

ELA, no, I don't have a modern scope nor do I have a filter to remove the 60Hz. Thanks for you comments.

 

I won't have results until next spring because I'm a snowbird and won't be back to this house until then. Hopefully, the system behaves until I get back.

[LeeG]

A powerline communication problem in one direction only is rare but not unheard of. The last one I remember was on this forum. The problem was opposite to your situation. The device was sending messages to the PLM with good reliability, even to the extent that Max Hop=1 messages were being received by the PLM but the ACK back to the device was not being received.

 

To date no one with digital equipment has traced the problem. Not sure if the PLM did not get the ACK sent in the correct time slot because of interference or the device did not receive it for the same reason. In this case the UPS is known to be a source of signal attenuation or noise. Not all create a problem but enough do that I always suggest putting all other electronic equipment on the same circuit as the PLM on a FilterLinc.

[Xathros]

Does anyone here have a sense about whether or not Insteon does any collision detection/prevention? Something like CSMA/CD. Is is possible that the noise at the zero cross was detected by the apl and mistaken as traffic preventing the apl from transmitting a response?

 

Just my uneducated .02

 

-Xathros

[brausse]

I've had several istances with the ISY994ir/PRO where it misses events if they occur at the same time. I've had to program around them by using Waits and Queries. I had a problem open where my security system would send 2 insteon events at the same time (2 EZIO6I inputs) and one always got missed. LeeG said this can happen. From this, I've assumed that there is no collision detection/prevention in the ISY994. I don't know if this goes back to the actual Insteon hardware/firmware or if it is a limitation of the ISY.

[Michel Kohanim]

Hi brausse,

 

ISY is a client to PLM. Unlike ISY, PLM processes everything serially. If the signal is valid, if it's not a duplicate of something else, and if ISY understand what it is, then it should be processed.

 

Collision detection is a function of PLM and not ISY.

 

So, what you want to do is to have your Event Viewer up and running on level 3 and then test a few scenarios that you had problems with. If you see traffic in Event Viewer, the ISY has seen it. If you don't, then PLM has lost it.

 

With kind regards,

Michel

[brausse]

Thanks for the explanation Michel. When I was having problems with missed status updates, they were missing in the level 3 trace so using your explanation, the PLM lost them.

[IndyMike]

Xathros,

 

You do yourself a disservice - that's worth at least a $1.25.

 

1) During the early days of Insteon we were able to pose questions directly to Smartlabs Engineering. At that time Smartlabs confirmed that Insteon units incorporated collision avoidance for both Insteon and X10 transmissions. I have no reason to believe this has changed over the years.

2) I have personally injected low level 120 Khz signals (50 mv) on the powerline and activated the collision avoidance in a 2412S PLM. The PLM effectively went mute - it could receive, but refused to transmit. I have not performed this on any recent units, but again have no reason to believe it has changed.

3) The fact that brausse observed noise at the zero crossing is unusual. Normally the zero crossing is clean since devices tend to draw current at the higher voltage levels. If the observed noise had 120 - 131 Khz content it could have activated the collision avoidance.

 

 

 

Does anyone here have a sense about whether or not Insteon does any collision detection/prevention? Something like CSMA/CD. Is is possible that the noise at the zero cross was detected by the apl and mistaken as traffic preventing the apl from transmitting a response?

 

Just my uneducated .02

 

-Xathros

[Xathros]

Thanks IndyMike!

 

-Xathros