Spurious OFF values from XAP network

[Steve Q]

Since moving to a new computer about a month ago, I am seeing more spurious results from my xap network. The spurious resuts are OFFs coming from my DS2405 switches that are connected to CR3110 current sensors on my electric baseboard heaters. I am wondering if the change from an RS232 (DS9097U) to the USB version (DS9490R) has somehow precipitated these spurious results. They also may be related to the UPS power backup that I installed on the computer early this summer. I think I have a sporadic "floating ground" which is causing the XAP devices to report their status.

It could also be some kind of electronic noise being induced into the DQ line, but I'm not sure.

I know my XAP network is running "on the edge", and I should probably be using a Hobbyboard Hub, but I really need a USB interface. (An edgeport is out of my price range).

Michael, do you think I would cause any problems by adding additional ground points to my XAP network? I can easily ground all of the CR3110 current sensor circuit boards to the baseboard heater ground. Or is this likely to introduce more noise to the XAP network? What do you think?

Steve Q

[Michael McSharry]

It is quite unlikely your problems are on the backside after xap messages are generated. I would focus on how the input to the ds2405 can change. For a ds2405 the input will be at a level at the instant of the polling interval. With ds2406 a state change can be sensed for any momentary change between the interval. I do know that a ds9490d wil hold up a ds2405 when the adapter is not be8ng used by the 1wire drivers, but the ds2405 will forget its state if it is connected to ds9097u and the 1wire drivers are not connected to that adapter. Unless you are running multiple adapters then this should not come into play. It you have a storage scope or latchng meter then you could instrument the ds2405 input to try to isolate between the ds2405 changing its state vs. an actual change in the input to the d2405. The idea of grounding is to bring everything to a common ground point to minimize the number of paths available. If you add additional then this goes against the theory, but real world is more practical than theory.

[Steve Q]

Michael, Thanks for the response. I do not have a scope or latching meter, so I cannot independently monitor the DS2405s. I believe they are in fact changing states and the output is real.

After giving it additional thought, here is what I think is going on: My baseboard heaters are controlled by 220V HVAC relays. The relays turn the the Heaters ON/OFF. Temperature control is via the thermostats built into the baseboard heaters. I monitor the ON/OFF state of the heaters via a CR3110 current transformer/DS2405 circuit on the 220V line to each heater. When the heater thermostat turns ON the DS2405 turns ON and vice versa. When the 220V relay to the heater is ON, I do not see any spurious OFF messages from the DS2405s. However, when the HVAC relay is OFF (no voltage to the heater), I am seeing the spurious OFF messages; and I think they are occuring when the thermostat closes (completes the circuit). When the thermostat closes (switches ON) this may be creating a voltage or noise spike that is being seen by the DS2405 and causing the spurious OFF. Although I don't understand why only OFF is sent.

Not all the heaters are producing the spurious results. This may be a clue; I will continue to look.

Since the spurious results are OFFs, this problem does not really have any impact on my monitoring system, so I can live with the situation. It is however an interesting problem and I certainly apperciate your expert opinion.

Steve Q

[Steve Q]

Michael,

I have been monitoring the occurance of spurious XAP messages. Here are a few observations:

1. I put a wireless current sensor on the same circuit as one of the DS2405 current sensors and I was able to confirm the spurious results are not due to some kind of transient current swing in the circuit. The wireless sensor triggered only when it should have and did not produce any spurious results. Meanwhile the DS2405 sensor continued to produce spurious messages.
2. The occurance of spurious results appears to be somehow related to other software running on my Homeseer computer. The higher the CPU load, the more spurious results I seem to see.
3. Additional Grounding of the XAP network made no difference.
4. The spurious message is always a "true" followed by a "false" within a second or less. This seems to be true regardless of the polling time.
5. I tried to use the debug feature of mcsxap1wire but I was not successful capturing an occurance of a spurious message. It creates a massive amount of data.
6. The occurance of the spurious message is not related to when the thermostat opens or closes. I confirmed this by manually adjusting the thermostat. I did not see any messages when the thermostat opened or closed.
   

Steve Q

[Steve Q]

Further to my previous post, point #2, after doing some video editing, I decided to burn a DVD on my Homeseer computer. After the DVD was successfully burned I checked the Homeseer log and found about 50 spurious XAP messages. This further leads me to believe that something is going on with the mcsxap1wire software that is generating these spurious messages.

Steve Q

[Steve Q]

I discovered that the "process priority" for xapmcs1wire.exe was set to "below normal" on my Homeseer computer (via Windows Task Manager). I changed the priority to "High". Since then I have seen only one spurious message even during heavy CPU utilization.

I also turned off "power management" on the USB ports.

I will report back in a few days a let you know if this is a permanent fix.

Steve Q

[Steve Q]

I have run for 3 days now after changing the process priority of xapmcs1wire.exe from "below normal" to "high". I have seen only 1 spurious result.

I noticed that when xapmcs1wire.exe is shutdown and restarted, it reverts to running with a priority "below normal". Therefore I added the following script to change the priority to high whenever Homeseer restarts and starts up my XAP network:
----------------------------------
' This vbs script sets the process priority for xapmcs1wire.exe to HIGH ( it will otherwise be set to below normal)
' Written by Steve Q - 11/21/2008
sub MAIN ()
Const HIGH = 256
strComputer = "."
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
Set colProcesses = objWMIService.ExecQuery _
("Select * from Win32_Process Where Name = 'xapmcs1wire.exe'")
For Each objProcess in colProcesses
objProcess.SetPriority(HIGH)
Next
hs.writelog "mcsXAP","Process Priority set to HIGH"
end sub
---------------------
This script is an adaptation of a script posted on the Microsoft website.


I believe I have solved my spurious results problem from my 1 wire network.

Steve Q

[nightwalker]

I've been having trouble with my 1wire network just going dead once in a while, could be days weeks once it ran a month. I never thought to check the priority on it. It may not solve my problem but gives me hope and something else to try.

[Steve Q]

Marty,

I tried the .net version when Michael first released it. I had the same issue. It stopped after 1 - 2 days. Therefore I am using version 2.4.13 of 1 wire status (xapmcs1wire.exe) and version 1.4.0.9 of the Homeseer mcsxap plugin.

Let me know what you find. I would also like to get the .net version running. But I have spent a lot of time getting my XAP stuff working and I am not going to change unless there is a good chance that it will work.

Steve Q

[nightwalker]

Marty,

I tried the .net version when Michael first released it. I had the same issue. It stopped after 1 - 2 days. Therefore I am using version 2.4.13 of 1 wire status (xapmcs1wire.exe) and version 1.4.0.9 of the Homeseer mcsxap plugin.

Let me know what you find. I would also like to get the .net version running. But I have spent a lot of time getting my XAP stuff working and I am not going to change unless there is a good chance that it will work.

Steve Q

I understand that, I know so little about xap stuff that I try not to touch it. Michael has been extremely helpful getting me going and I think I've become the albatross around his neck. Right now I'm using the Hybrid version and to be honest I don't know where the problem lies. When It happens and it could be days or even weeks between those events but it's the whole network that freezes, not just the plug-in. My next step will be to shut down the plug-in and run the network without the link to HS and see if it still goes dead. I'm not sure exactly what that's going to tell me but it should narrow the search a bit.

[Steve Q]

When you say "the whole network freezes" are you talking about the XAP network or your entire LAN (ie computers cant talk to each other). Maybe you could use Windows task manager to shut down processes to find out which one is causing the lockup.

Steve Q

[nightwalker]

It's just the 1wire network that goes dark. All three programs that run it simply stop reporting. The LAN is still doing fine during. Rebooting the HS server solves the whole thing for a couple of weeks or days but I'd like to at some point figure out why it just stops. Looking at the hybrid plug-in and mcsxaphub and xap1wire all have stopped reporting. Shutting down the plug-in and bringing up the 1wire viewer shows the same thing, no polling, no heartbeat, no nothing. It's just weird how it'll go sometimes for a month with no troubles other times just a day.

I guess if there wasn't a problem once in a while to fight with this stuff would be boring.

[Steve Q]

Marty,

I would think it would be most unlikely that all 3 applications are dying at the same time! I suspect that mcsxap1wire is stopping. When it stops you won't see anything on the hub or the Homeseer plugin. The next time your XAP network stops, before restarting Homeseer, Open up the IO window of mcsxap1wire and check for activity. If there is no activity, or if you can't open the window, close mcsxap1wire and restart it. Then check to see if your network is back running. You may have an XAP device that is bad and is sending bad data which causes mcsxap1wire to lockup.

Steve Q

[nightwalker]

I have brought up the browser window of mcsxap1wire and found no activity. I haven't tried shutting just that down and restarting it to see what happens. Right now the only thing on the network is 4 temp sensors, pretty simple really. I was hoping to use the 1wire network for more than this of course but not until I can determine why it goes dead and can get it to be a lot more reliable. I have over time unplugged a leg to see if maybe it's a bad sensor but so far no matter which sensor is plugged in it goes dead sooner or later.

I will try restarting mcsxap1wire without doing anything else next time it happens. Problem with this whole process is it could be a month before it happens again. Makes for a long long troubleshooting process. In the meantime I have bumped the hub and mcsxap1wire to above normal priority to see if that helps at all.

[Steve Q]

I hear ya. Trouble shooting an XAP network is a real pain. I have 16 devices. Every time I have added something new, it seems like a whole new set of problems came up. My biggest frustration is that I cannot get a DS2406 to work; ever. I've tried everything but no go. The DS2405 works fine, but it is now discontinued. Good luck. Keep us posted on your progress.

Steve Q