FCC Rule: Big brother watching?

[sjb]

Hi all,

I just installed a new PC for a client today (here in the US) and noticed
that there was a piece of paper with "declaration of conformity with FCC
rules for electromagnetic compatibility" included with the mouse and
keyboard. They aren't wireless. Either way, even if they were, here is the
part that I'm curious about.

It says at the bottom, that in order to "comply" with the aforementioned
declaration that the device must, according to part 15 of FCC rules:

1)this device may not cause harmful interference

and here's the freaky one,

2)this device must accept any interference received, including interference
that may cause undsired operation.

WTF!

Why would they insist that a device accept harmful/debilitating
interference?

Just curious,

Scott

 

[Eeyore]

Hi all,

I just installed a new PC for a client today (here in the US) and noticed
that there was a piece of paper with "declaration of conformity with FCC
rules for electromagnetic compatibility" included with the mouse and
keyboard. They aren't wireless. Either way, even if they were, here is the
part that I'm curious about.

It says at the bottom, that in order to "comply" with the aforementioned
declaration that the device must, according to part 15 of FCC rules:

1)this device may not cause harmful interference

and here's the freaky one,

2)this device must accept any interference received, including interference
that may cause undsired operation.

WTF!

Why would they insist that a device accept harmful/debilitating
interference?

It's called electromagnetic immunity.

They're just getting up to date. This has been the norm in Europe and other
parts of the world for ages.

Sounds badly worded to me though.

Graham

 

[Tom Biasi]

Hi all,

I just installed a new PC for a client today (here in the US) and noticed
that there was a piece of paper with "declaration of conformity with FCC
rules for electromagnetic compatibility" included with the mouse and
keyboard. They aren't wireless. Either way, even if they were, here is the
part that I'm curious about.

It says at the bottom, that in order to "comply" with the aforementioned
declaration that the device must, according to part 15 of FCC rules:

1)this device may not cause harmful interference

and here's the freaky one,

2)this device must accept any interference received, including
interference that may cause undsired operation.

WTF!

Why would they insist that a device accept harmful/debilitating
interference?

Just curious,

Scott

This is old law. In the USA Part 15 are laws covering electronic
step-children.
They are not allowed to bother anybody and if anybody bothers them, too bad.
In the past CB radio walkie-talkies under 100 mW were under Part 15 law.
Now-a-days just about any device is subject to part 15.

Tom

 

[sjb]

Hi all,

I just installed a new PC for a client today (here in the US) and noticed
that there was a piece of paper with "declaration of conformity with FCC
rules for electromagnetic compatibility" included with the mouse and
keyboard. They aren't wireless. Either way, even if they were, here is the
part that I'm curious about.

It says at the bottom, that in order to "comply" with the aforementioned
declaration that the device must, according to part 15 of FCC rules:

1)this device may not cause harmful interference

and here's the freaky one,

2)this device must accept any interference received, including
interference that may cause undsired operation.

WTF!

Why would they insist that a device accept harmful/debilitating
interference?

Just curious,

Scott

Ok, but why would I have to "accept" interference? I would think that by
sheilding/filtering my electronics that I wouldn't be hurting anyone.

Scott

 

[Lord Garth]

Ok, but why would I have to "accept" interference? I would think that by
sheilding/filtering my electronics that I wouldn't be hurting anyone.

Scott

It simply means that while the unit may not operate as expected while in the
presence of an interfering field, it will not be damaged by that
interference.

 

[Phil Allison]

"sjb"

2)this device must accept any interference received, including
interference that may cause undsired operation.

WTF!

Why would they insist that a device accept harmful/debilitating
interference?

** Because every electronic device made does just that - it exists in a
radio frequency interference filled environment.

The word "accept" is being used here with the meaning of " live with " or
tolerate all the legally permitted forms of radio frequency interference.
GSM phones at close range would be a big one.

The makers of the item must design it to be tolerant of such interference
and even if the device is made to misbehave this does not lead to disaster -
ie it simple freezes unit the GSM phone is moved away.


BTW

YOU added the words " harmful/debilitating".



........ Phil

 

[Impmon]

2)this device must accept any interference received, including interference
that may cause undsired operation.

WTF!

Why would they insist that a device accept harmful/debilitating
interference?

That disclaimer has been on just about every electronic items for the
last couple decades. Never really bothered to figure out the warning
#2

 

[Puckdropper]

That disclaimer has been on just about every electronic items for the
last couple decades. Never really bothered to figure out the warning
#2

It may be possible that some mad EE comes up with a way to solve the
interference problem his device is getting... by actively seeking out the
sources of the interference and doing something to them. Ok, Star Trek
TNG analogy aside, it's possible an active anti-interferance scheme could
mess with another device. It's a play nice type rule, as well as an
extension of rule 1.

Just my opinion.

Puckdropper

 

[Michael Black]

It may be possible that some mad EE comes up with a way to solve the
interference problem his device is getting... by actively seeking out the
sources of the interference and doing something to them. Ok, Star Trek
TNG analogy aside, it's possible an active anti-interferance scheme could
mess with another device. It's a play nice type rule, as well as an
extension of rule 1.

Is the second bit really in Part 15? It may simply be there to inform
the consumer that they have to live with interference, and they put in
the line to counter the first bit. "This is legal according to that
first line, so why am I not protected by the same token?"

The intent is clear. People using transmitters are only responsible
for interference if they are using out of spec transmitters. Being nearby
so it can overload that audio amplifier is not a crime. (But a transmitter
that isn't "clean", ie putting out harmonics that land in the tv spectrum,
is the problem when the neighbor is getting bad tv reception as a result.)
Those without technical knowledge blame the transmitters, whether or
not they are the actual problem.

Part 15 even includes some things where the right to use the specific
radio frequencies is overriden by licensed users of those frequencies.
So those cheap 27MHz walkie talkies can't interfere with licensed users
(actually I gather there may no longer be a license requirement for
CB), but if a licensed user comes on the frequency, the Part 15 user
can't complain. They have to standby because they are a secondary
user of those frequencies.

Indeed, the disclaimer may be a general boilerplate that is used
for any time a Part 15 disclaimer is needed, so the fact
that one device actual receives radio signals (that wireless
keyboard using 27MHz) and another is merely interfered with (that
wired keyboard sends extra characters everytime Joe next door transmits)
isn't differentiated.

Michael

 

[jasen]

Ok, but why would I have to "accept" interference? I would think that by
sheilding/filtering my electronics that I wouldn't be hurting anyone.

if your device latched up and caught fire everytime a mobile phone came near
that could be bad.

Bye.
Jasen

 

[sjb]

"sjb"


** Because every electronic device made does just that - it exists in a
radio frequency interference filled environment.

The word "accept" is being used here with the meaning of " live with "
or tolerate all the legally permitted forms of radio frequency
interference. GSM phones at close range would be a big one.

The makers of the item must design it to be tolerant of such interference
and even if the device is made to misbehave this does not lead to
disaster - ie it simple freezes unit the GSM phone is moved away.


BTW

YOU added the words " harmful/debilitating".



....... Phil

Yes, I interpreted the second part to mean that if someone were to
intentionally try to mess with my electronic systems, then I would have to
allow it. My parnoid thoughts were along the lines of, if the government
wanted to hack into a system by some electronic means then I would have to
let them do it.I know, eavesdropping would be a passive thing, but perhaps
they would use active methods to get into a system.

This is why I wear the foil hat!

Scott

 

[sjb]

Hi all,

I just installed a new PC for a client today (here in the US) and noticed
that there was a piece of paper with "declaration of conformity with FCC
rules for electromagnetic compatibility" included with the mouse and
keyboard. They aren't wireless. Either way, even if they were, here is the
part that I'm curious about.

It says at the bottom, that in order to "comply" with the aforementioned
declaration that the device must, according to part 15 of FCC rules:

1)this device may not cause harmful interference

and here's the freaky one,

2)this device must accept any interference received, including
interference that may cause undsired operation.

WTF!

Why would they insist that a device accept harmful/debilitating
interference?

Just curious,

Scott

Thanks for all the replys...I think I understand a little better now! I was
interpreting it the wrong way.

Scott

 

[Michael A. Terrell]

It's called electromagnetic immunity.

They're just getting up to date. This has been the norm in Europe and other
parts of the world for ages.

Sounds badly worded to me though.

Graham

Catching up? It has been in part 47 of the CFR for as long as I can
remember. Take your US bashing somewhere else, moron.



--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Michael A. Terrell]

That disclaimer has been on just about every electronic items for the
last couple decades. Never really bothered to figure out the warning
#2

It means that if you buy some poorly designed piece of electronic
crap that is affected by a legal, licensed transmitter, you have no
right to complain.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Impmon]

It means that if you buy some poorly designed piece of electronic
crap that is affected by a legal, licensed transmitter, you have no
right to complain.

Actually, I could return the poorly designed piece of crap and
exchange it for something else. When a store sees a high number of
returns on same brand or model, they can refuse to carry them and the
company in the end would either have to work on the quality or suffer.

 

[Eeyore]

Actually, I could return the poorly designed piece of crap and
exchange it for something else. When a store sees a high number of
returns on same brand or model, they can refuse to carry them and the
company in the end would either have to work on the quality or suffer.

That's why they aren't designed that badly.

Graham

 

[Michael A. Terrell]

Actually, I could return the poorly designed piece of crap and
exchange it for something else. When a store sees a high number of
returns on same brand or model, they can refuse to carry them and the
company in the end would either have to work on the quality or suffer.

There are some locations you may not find any model that works
properly.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Michael Black]

Actually, I could return the poorly designed piece of crap and
exchange it for something else. When a store sees a high number of
returns on same brand or model, they can refuse to carry them and the
company in the end would either have to work on the quality or suffer.

I think you've missed the point. This particular matter will only
come up in the presence of a strong radio signal. Like if you live
near a broadcast station, or next to an amateur radio station. Elsewhere,
the signal levels have dropped off enough that they won't be strong
enough at your end to cause any problems.

So the manufacturer can decide to design something so nothing will
interfere with it by accident (we're assuming that the unit isn't
an actual receiver, where obviously things become different), and
charge accordingly. Or, it can design something so a reasonably
strong signal won't be a problem, and that will take care of
most situations.

The person living next to a transmitter will have problems, but
they would be a relative handful compared to the overall number
of units sold.

This is not a new issue, just because the manufacturers now
put such disclaimers in the manuals.

Michael