Hi,
I wonder if someone could help me please, I have an outdoor Wi-Fi system of external routers that are connecting various buildings for remote sensors, the routers are the IP-COM P115AP 2.4ghz routers, they all work perfectly for a few weeks and then 2 or 3 of them just stop working No SSID being broadcast, if I reset just the external routers all is ok again, I am thinking that we are in the countryside and the power may be a little noisy ie micro power outages, is there something that I could plug into the power supplies for the routers or maybee make something like a smoothing capacitor ?

Thanks In Advance
Stuart

 

Have you measured/observed the voltage levels at the router locations? Sometimes, long extension cords cause voltage drop. Does the voltage change much?

If there is an occasional heavy load on the same circuit, there could be a voltage anomaly.

If the UPS that you are using is old, or of questionable performance, consider replacing the batteries inside. Typically, the batteries are 12v, sealed lead acid type, and readily available, at a cost that is much lower than a new UPS ... Have done this once or twice, with good result.

 

And it may have nothing to do with power and everything to do with the nature of the traffic over the router. It's even possible for your OS and browser to bring down your router. I'm nowhere near enough of an expert to explain why, but I know it happens.

 

Are they by any chance subject to temperature extremes?

 

Hi,

Thanks for your comments, the external routers have a plug in 12 volt 1.5 amp dc power supply which is inside obviously, they are not on a ups, my sensors simply connect to the router and send temperatures via MQTT to a mosquito server on a raspberry pi, as I say all is well for a few weeks and then a few of the routers will just stop working, when I reset I only reset the routers and not my sensors so this proves that it is not my sensors, there are pumps and inverter drives on the same consumer units and lights do dim etc which is why I think some sort of capacitor device would compensate.

thanks
Stuart

 

And it may have nothing to do with power and everything to do with the nature of the traffic over the router. It's even possible for your OS and browser to bring down your router. I'm nowhere near enough of an expert to explain why, but I know it happens.

Hi Wayneh,

I have 2 or 3 other routers transmitting the same data from different buildings which never go off so I am assuming that this theory would be ruled out, thanks for the suggestion though.

Stuart

 

Are they by any chance subject to temperature extremes?

Hi Jterblanche,

No they are all in the same reasonable temperatures

Thanks
Stuart

 

Have you measured/observed the voltage levels at the router locations? Sometimes, long extension cords cause voltage drop. Does the voltage change much?

If there is an occasional heavy load on the same circuit, there could be a voltage anomaly.

If the UPS that you are using is old, or of questionable performance, consider replacing the batteries inside. Typically, the batteries are 12v, sealed lead acid type, and readily available, at a cost that is much lower than a new UPS ... Have done this once or twice, with good result.

Hi drc_567

Yes this is a good idea, I haven't tried this but I would need some sort of device to monitor the power, but I have no idea what to use as it is probably an occurrence when I am not testing manually.

Thanks
Stuart

 

For what it's worth, it could actually be over-voltage as much as under-voltage. I had a router that came with a wall wart that supplied a good 18V AC or so instead of the router's labelled input of 12V. So every so often - and it seemed random to me - the router would cut out. Replacing the wall wart fixed it completely. Along the way I learned that this was a very common failure mode for routers back in the day. Your routers probably don't have wall wart transformer-based power adapters, and instead have nicely regulated SMPSs.

EDIT - An ad for this just showed up in my email. Just a thought.
http://www.solidsignal.com/pview.as...ium=email&utm_source=inhouse&utm_content=slim

 

Hi Wayneh,

I have just put some surge protector plugs on them so this should deal with any spikes, if it continues to be a problem I guess I am looking at ups's but I was hoping to use something cheaper as 12 x ups = lot of money and I am doing all of this for free for a registered charity..

thanks
Stuart

 

Hi Wayneh,

I have just put some surge protector plugs on them so this should deal with any spikes, if it continues to be a problem I guess I am looking at ups's but I was hoping to use something cheaper as 12 x ups = lot of money and I am doing all of this for free for a registered charity..

thanks
Stuart

My past few routers had a setup option to restart every day, one per week, once per month... (Then pick what time of day to reset).

 

Hi Gopher,

I think the routers are locking up/freezing so I don't think that option on the router would help me, I think I need to get to the root of the problem and sort it out, thanks for your input though.


Stuart

 

If you can do a little reverse engineering, something like these http://www.analog.com/media/en/technical-documentation/data-sheets/ADM803_809_810.pdf may work to generate a reset signal.

Although not foolproof, you might be able to take a latching relay such as https://www.digikey.com/products/en?keywords=z749-nd, if the internal supply to the processor was 5V to act as a monitor.

the idea would be to push a button to turn a LED off with one coil and have the reset generator turn the LED on.
If you then detected the problem, you could then try to reverse engineer the correct solution.

So, the idea is when you power the troublesome one up, push a button. Hopefully the LED would light if there was a power glitch and you found the WIFI module not working. Initial testing only needs power and ground.

 

Two things...
Swap the routers round and see if the fault follows a router or its location...
If it seems to be the location, first swap the power supplies and see if the fault follows them
Not foolproof but a good, simple diagnostic that may pin down your issue.

If it seems to be location than it could be a mains borne issue as suggested and a monitor may tell you something. That an electronic supply, perhaps a buck converter stepping down fro mm a higher voltage transformer, may help, particularly if yiou add some additional capacitance to its supply.

You should also look at the connected devices and the config, disable anything you are not using, particularly UPNP if it is on and any router update protacol unless its absolutely necessary.
I assume you are in WDS mode ion all but the master?

What antennas do you have, and are there any potential sources of interfeerance near the affected units?
Have you updated all the firmware to the same version and preferably set the all, but the master, to the same backed up config?

The units support multiple methods of routing bridging and distribution but WDS is probably the best choice as all units will be set up identically...
Make sure you do not have the channel set to auto as it will fail at some point even if it works when first set up.

Check the documentation but I think the first unit, connected to your internet connection, wirelessly or wired, needs to be in routed mode with a fixed channel. after all the others are identical channel SSID, security the lot... You will end up with a fault tolerant mesh, at least you will if they are not in a long line but even that should work.

What are your sensors running on.... if it is something which you can program you might be able to detect lack of coms and restart the router with the device by power cycling it.
I do this with HMI's cant ping the world for a while... restart everything, still cant ping the world, restart again but after a much longer delay.
If all else fails use a cheap plugin digital time switch, rough but effective when rebooted at a fixed daily time or interval.

I will be surprised if its power issues, they would have to be pretty bad to regularly brown out what looks like a well made and appointed unit which likely has a wtchdog routine.

Hope that helps,
Al

 

Hi Al,

Thanks for your suggestions, the first router at my base is indeed in router mode all others are in universal repeater Mode, as I said all works fine for a few weeks and then I have to reset a couple of them, I have just installed some surge protectors just to see if they make any difference, if they are still playing up I think I will make some auto daily resetters like you suggest.

Thanks
Stuart

 

One workaround might be to connect them to a wall timer that shuts their power off and then back on, say once a day, if you can tolerate a short interruption in the signal.

 

WDS will likely be more stable than universal repeter mode, URM is a little complex and tries to be too clever for its own good much of the time.
Also check your channel allocation, in WDS all devices must be locked on the same channel, something else URM attempts to avoid, usually badly with many devices.

Al