Scott M
August 11th 03, 11:22 AM
DaveC wrote:
> Took my Clifford remote (2 button, for IG 200) in to Clifford dealer. He
> opened it up and looked at the back of the PCB where he showed me small
> scratches the assembler had made.
>
> He said that these scratches correspond to the unique digital ID of the alarm
> (to keep anyone with a similar alarm from stealing your car, I presume). I
> didn't fully understand the significance of these.
On the PCB there will be something like 8 circuit tracks connected to
pins on the chip. The tracks will all be grounded (or dragged high.) By
scratching through various track you break the connections and set a
unique[1] binary value for that remote (connection intact = 0,
connection broken = 1 or vice-versa.)
> If I buy a used 2-button remote of the same model, is it possible to
> re-program it for my alarm? Do I need to?
a) Technically, yes.
b) Probably not reading what you say below.
> I thought that all you needed to do is go through the programming sequence
> that is listed in the owner's manual to get the alarm to recognize a new
> remote. This "scratch remote" stuff has me confused.
The "programming sequence" will be to set the alarm unit to recognise
the code set in the remote.
--
Scott
[1] Well, 1 of 256[2] combinations
[2] Or 2^x where x is the number of tracks in the remote.
Where are we going and why am I in this handbasket?
> Took my Clifford remote (2 button, for IG 200) in to Clifford dealer. He
> opened it up and looked at the back of the PCB where he showed me small
> scratches the assembler had made.
>
> He said that these scratches correspond to the unique digital ID of the alarm
> (to keep anyone with a similar alarm from stealing your car, I presume). I
> didn't fully understand the significance of these.
On the PCB there will be something like 8 circuit tracks connected to
pins on the chip. The tracks will all be grounded (or dragged high.) By
scratching through various track you break the connections and set a
unique[1] binary value for that remote (connection intact = 0,
connection broken = 1 or vice-versa.)
> If I buy a used 2-button remote of the same model, is it possible to
> re-program it for my alarm? Do I need to?
a) Technically, yes.
b) Probably not reading what you say below.
> I thought that all you needed to do is go through the programming sequence
> that is listed in the owner's manual to get the alarm to recognize a new
> remote. This "scratch remote" stuff has me confused.
The "programming sequence" will be to set the alarm unit to recognise
the code set in the remote.
--
Scott
[1] Well, 1 of 256[2] combinations
[2] Or 2^x where x is the number of tracks in the remote.
Where are we going and why am I in this handbasket?