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#1
Posted to alt.electronics,comp.sci.electronics,rec.electronics,sci.electronics,sci.electronics.misc
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PIR interfering with wireless network
We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking?
-- http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com If you're cross-eyed and have dyslexia, can you read all right? |
#2
Posted to alt.electronics,comp.sci.electronics,rec.electronics,sci.electronics,sci.electronics.misc
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PIR interfering with wireless network
On Fri, 30 Jan 2009 18:20:10 -0000, "Peter Hucker"
wrote: We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? --- If its PIR it shouln't. PIR is Passive Infra Red, and it's body heat which triggers the sensor, not anthing the device transmits. http://www.glolab.com./pirparts/pirmanual.PDF Maybe the wiring is affecting the strength of the RF field areound where she sits. JF |
#3
Posted to alt.electronics,comp.sci.electronics,rec.electronics,sci.electronics,sci.electronics.misc
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PIR interfering with wireless network
On Fri, 30 Jan 2009 20:18:14 -0000, John Fields wrote:
On Fri, 30 Jan 2009 18:20:10 -0000, "Peter Hucker" wrote: We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? --- If its PIR it shouln't. PIR is Passive Infra Red, and it's body heat which triggers the sensor, not anthing the device transmits. http://www.glolab.com./pirparts/pirmanual.PDF I'm not sure if it's PIR or not. Aren't a lot of them nowadays multifunction? Maybe the wiring is affecting the strength of the RF field areound where she sits. The wiring? It shouldn't have that strong a field from its wiring surely? The effect is as such: within about 2-3 metres the network is unusable. The next 2-3 metres it works most of the time. After that it's almost perfect. -- http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com Financial Retirement Plan: If you had purchased $1000.00 of Nortel stock one year ago, it would now be worth $49.00. With Enron, you would have had $16.50 left of the original $1,000.00. With WorldCom, you would have had less than $5.00 left. But, if you had purchased $1,000.00 worth of Beer one year ago, drank all the beer, then turned in the cans for the aluminium recycling refund, you would have had $214.00. Based on the above, current investment advice is to drink heavily and recycle. |
#4
Posted to alt.electronics,comp.sci.electronics,rec.electronics,sci.electronics,sci.electronics.misc
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PIR interfering with wireless network
On Fri, 30 Jan 2009 20:44:44 -0000, "Peter Hucker"
wrote: On Fri, 30 Jan 2009 20:18:14 -0000, John Fields wrote: On Fri, 30 Jan 2009 18:20:10 -0000, "Peter Hucker" wrote: We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? --- If its PIR it shouln't. PIR is Passive Infra Red, and it's body heat which triggers the sensor, not anthing the device transmits. http://www.glolab.com./pirparts/pirmanual.PDF I'm not sure if it's PIR or not. Aren't a lot of them nowadays multifunction? --- Dunno; you were the one who tagged it as PIR. --- Maybe the wiring is affecting the strength of the RF field areound where she sits. The wiring? It shouldn't have that strong a field from its wiring surely? --- I didn't say the wiring was responsible for generating the field, I said it might have an _effect_ on the [already existing] field. JF |
#5
Posted to alt.electronics,comp.sci.electronics,rec.electronics,sci.electronics,sci.electronics.misc
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PIR interfering with wireless network
Ok, I have been reading this thread with great amusement. :-)
A couple of things to clear up. A PIR motion detector is a Passive Infrared detector that detects movement in a space based upon focused infrared temperature changes thru a Fresnel Lens of an object in front of the detector. It cannot detect thru walls or glass. A "Dual-Tech" Motion Detector uses two(dual) technologies to detect motion or movement in a space. It uses a PIR sensor and a Microwave sensor. The microwave sends out pulses of microwave energy into the space if the return signals change due to a person/object moving in the space (or outside the space because it can see thru walls) and there is a temperature change that has been detected by the PIR at the same time there is an alarm. This is less false alarm prone than the simple PIR. All that being said the simple way to prove or disprove that the detector is causing the problem is get the security tech to power down the panel and see what happens. My guess is that something else other than the detector is causing the problem and it is just a coincidence that it happened at the same time of the install. It would be my guess that one of the following is the cause. 1) The transceiver was moved from its original position and the range in this area was modified. 2) Some metal object has been moved/placed at a point that is deflecting the signal. 3) A fluorescent light bulb/ballast is failing and giving off massive amount of RFI causing the interference. 4) Sun Spots are reaching a peak in your area. 5) The earth magnetic field has been modified in ways that cannot be fully explained. i.e. Government Plot!!! 5) All of the above. 6) Other I have used the KISS method in the above description to ease the pain. Some error in wording may be found. Whoops!!! Sorry for any confusion. Hope that helps you to find your problem. Wireless is never perfect. Good luck and have a nice day. Les "John Fields" wrote in message ... On Fri, 30 Jan 2009 20:44:44 -0000, "Peter Hucker" wrote: On Fri, 30 Jan 2009 20:18:14 -0000, John Fields wrote: On Fri, 30 Jan 2009 18:20:10 -0000, "Peter Hucker" wrote: We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? --- If its PIR it shouln't. PIR is Passive Infra Red, and it's body heat which triggers the sensor, not anthing the device transmits. http://www.glolab.com./pirparts/pirmanual.PDF I'm not sure if it's PIR or not. Aren't a lot of them nowadays multifunction? --- Dunno; you were the one who tagged it as PIR. --- Maybe the wiring is affecting the strength of the RF field areound where she sits. The wiring? It shouldn't have that strong a field from its wiring surely? --- I didn't say the wiring was responsible for generating the field, I said it might have an _effect_ on the [already existing] field. JF |
#6
Posted to alt.electronics,comp.sci.electronics,rec.electronics,sci.electronics,sci.electronics.misc
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PIR interfering with wireless network
I covered it with a biscuit tin lid today, and the problem immediately vanished. I happend to spot a workman installing more of them and told him to remove it. He said therew as absolutely no way it could be causing that problem, but I persuaded him to remove it while a continuous ping was on the screen of a wireless laptop. It could clearly be seen that as soon as he unplugged it, everything worked, and when he put it back, packets disappeared. He told me it used microwaves, but couldn't tell me the frequency (although he thought it was meant to be substantially higher than 2.4GHz). All of the detectors throughout the building look identical, but only this one appeared to cause problems. Perhaps it was faulty and was oscillating at half the correct frequency?
The whole of the new corridor still hates higher numbered channels for no apparent reason. Channel 1 works perfectly, channel 6 works with older laptops but not new ones(?!) and channel 11 works with nothing. There is only that one transmitter in range there, so who knows what's going on! On Sat, 31 Jan 2009 16:56:24 -0000, ABLE1 wrote: Ok, I have been reading this thread with great amusement. :-) A couple of things to clear up. A PIR motion detector is a Passive Infrared detector that detects movement in a space based upon focused infrared temperature changes thru a Fresnel Lens of an object in front of the detector. It cannot detect thru walls or glass. A "Dual-Tech" Motion Detector uses two(dual) technologies to detect motion or movement in a space. It uses a PIR sensor and a Microwave sensor. The microwave sends out pulses of microwave energy into the space if the return signals change due to a person/object moving in the space (or outside the space because it can see thru walls) and there is a temperature change that has been detected by the PIR at the same time there is an alarm. This is less false alarm prone than the simple PIR. All that being said the simple way to prove or disprove that the detector is causing the problem is get the security tech to power down the panel and see what happens. My guess is that something else other than the detector is causing the problem and it is just a coincidence that it happened at the same time of the install. It would be my guess that one of the following is the cause. 1) The transceiver was moved from its original position and the range in this area was modified. 2) Some metal object has been moved/placed at a point that is deflecting the signal. 3) A fluorescent light bulb/ballast is failing and giving off massive amount of RFI causing the interference. 4) Sun Spots are reaching a peak in your area. 5) The earth magnetic field has been modified in ways that cannot be fully explained. i.e. Government Plot!!! 5) All of the above. 6) Other I have used the KISS method in the above description to ease the pain. Some error in wording may be found. Whoops!!! Sorry for any confusion. Hope that helps you to find your problem. Wireless is never perfect. Good luck and have a nice day. Les "John Fields" wrote in message ... On Fri, 30 Jan 2009 20:44:44 -0000, "Peter Hucker" wrote: On Fri, 30 Jan 2009 20:18:14 -0000, John Fields wrote: On Fri, 30 Jan 2009 18:20:10 -0000, "Peter Hucker" wrote: We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? --- If its PIR it shouln't. PIR is Passive Infra Red, and it's body heat which triggers the sensor, not anthing the device transmits. http://www.glolab.com./pirparts/pirmanual.PDF I'm not sure if it's PIR or not. Aren't a lot of them nowadays multifunction? --- Dunno; you were the one who tagged it as PIR. --- Maybe the wiring is affecting the strength of the RF field areound where she sits. The wiring? It shouldn't have that strong a field from its wiring surely? --- I didn't say the wiring was responsible for generating the field, I said it might have an _effect_ on the [already existing] field. JF -- http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com What comes after 69? Mouthwash. |
#7
Posted to alt.electronics,comp.sci.electronics,rec.electronics,sci.electronics,sci.electronics.misc
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PIR interfering with wireless network
On Sat, 31 Jan 2009 15:07:06 -0000, John Fields wrote:
On Fri, 30 Jan 2009 20:44:44 -0000, "Peter Hucker" wrote: On Fri, 30 Jan 2009 20:18:14 -0000, John Fields wrote: On Fri, 30 Jan 2009 18:20:10 -0000, "Peter Hucker" wrote: We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? --- If its PIR it shouln't. PIR is Passive Infra Red, and it's body heat which triggers the sensor, not anthing the device transmits. http://www.glolab.com./pirparts/pirmanual.PDF I'm not sure if it's PIR or not. Aren't a lot of them nowadays multifunction? --- Dunno; you were the one who tagged it as PIR. Force of habit, as that's all they used to be. -- http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com During her annual checkup, the well-constructed miss was asked to disrobe and climb onto the examining table. "Doctor," she replied shyly, "I just can't undress in front of you." "All right," said the physician, "I'll flick off the lights. You undress and tell me when you're through." In a few moments, her voice rang out in the darkness: "Doctor, I've undressed. What shall I do with my clothes?" "Put them on the chair, on top of mine." |
#8
Posted to alt.electronics,sci.electronics.misc
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PIR interfering with wireless network
On Jan 31, 4:20 am, "Peter Hucker" wrote:
We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? You can now get ones that use microwave detection as well as PIR, they are called "Dual PIR" sensors: http://www.ness.com.au/ViewProduct.a...Number=100-210 10.5GHz for the microwave A normal PIR sensor would not cause any issues like this as they are passive. You can simply swap a Dual PIR for a normal PIR no probems. Sensors only need a 4 conductor cable, two for power (12V), two for the contact. Dave. |
#9
Posted to alt.electronics,sci.electronics.misc
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PIR interfering with wireless network
On Fri, 30 Jan 2009 21:29:33 -0000, David L. Jones wrote:
On Jan 31, 4:20 am, "Peter Hucker" wrote: We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? You can now get ones that use microwave detection as well as PIR, they are called "Dual PIR" sensors: http://www.ness.com.au/ViewProduct.a...Number=100-210 10.5GHz for the microwave A normal PIR sensor would not cause any issues like this as they are passive. You can simply swap a Dual PIR for a normal PIR no probems. Good point, I'll just tell them to put in a passive in any rooms with problems if I can prove it's that. We've always had detectors though and never had problems, so maybe it's faulty? Or the new ones are on a different band. If it's using 2.4GHz, in my opinion it's wrong. Using the same band as wireless networks in an office is just plain stupid. Sensors only need a 4 conductor cable, two for power (12V), two for the contact. Odd that they left a bit of approx 10 core cable then (and that was the only thing they were fitting at the time). Unless it uses a different core for each type of detection? -- http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com A very shy guy goes into a bar and sees a beautiful woman sitting at the bar. After an hour of gathering up his courage, he finally goes over to her and asks, tentatively, "Um, would you mind if I chatted with you for a while?" To which she responds by yelling, at the top of her lungs, "No, I won't sleep with you tonight!" Everyone in the bar is now staring at them. Naturally, the guy is hopelessly and completely embarrassed and he slinks back to his table. After a few minutes, the woman walks over to him and apologizes. She smiles at him and says, "I'm sorry if I embarrassed you. You see, I'm a graduate student in psychology and I'm studying how people respond to embarrassing situations." To which he responds, at the top of his lungs, "WHAT DO YOU MEAN, $200?" |
#10
Posted to alt.electronics,comp.sci.electronics,rec.electronics,sci.electronics,sci.electronics.misc
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PIR interfering with wireless network
Peter Hucker wrote:
We have a wireless network at work which appears to have gone downhill since the workmen installed PIRs for the burglar alarm. One of them in particular appears to cause dropped packets the closer a laptop is to it. Is this possible?? It's not a wireless PIR as far as I know, as I can see some leftover cable he was using which is a multicore (about 10 cores) type similar to phone systems, so I assume this is for the signal aswell as power. The person in that office swears blind that there were absolutely no problems until the PIR was installed above her desk, and now when I check, about 60% of the packets are being dropped. Moving her laptop to the opposite side of the room it drops only 5% of packets. PIRs used to just pick up infrared of your bodyheat, but I think now they are also motion sensors? Perhaps this means they are sending out a signal and bouncing it off you? Perhaps this could interfere with wireless networking? The IR sensor might be one of the dual sensor (expensive!) type that also include a microwave T/R motion sensing circuit. That would be very likely to interfere with wireless networking systems. The security company should be able to tell you for sure. -- W . | ,. w , "Some people are alive only because \|/ \|/ it is illegal to kill them." Perna condita delenda est ---^----^--------------------------------------------------------------- |
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