Does anyone have knowledge of any standards for Magnetic Key Readers?
I am currently interested in re-designing a commercially available one with
a simpler PIC-based product, but I understand that there is a standard to
which they have to conform ("Wiggan" protocol?)
Any pointers would be greatly appreciated
Cheers & thanks in advance
Ken Parkyn
I don't mind dying, I just don't want to be there when it happens...
>Does anyone have knowledge of any standards for Magnetic Key Readers?
>I am currently interested in re-designing a commercially available one with
>a simpler PIC-based product, but I understand that there is a standard to
>which they have to conform ("Wiggan" protocol?)
>Any pointers would be greatly appreciated
>Cheers & thanks in advance
>Ken Parkyn
Are you speaking of the credit card type readers or the type that you place
the id card on a flat plate?
>>Does anyone have knowledge of any standards for Magnetic Key Readers?
>>Ken Parkyn
>Are you speaking of the credit card type readers or the type that you place
>the id card on a flat plate?
>michael
No, these are magnetic keys; flat plastic keys with small magnets mounted
inside in a pattern which is scanned and ok'd by hall effect devices The
key is inserted into a slot and both sides are read by hall effect
transducers which input the data pattern to a uProcessor. After evrifying
that the key has a valid encoded pattern, a "Weigan" typye signal is output
to a main processor which unlatches the door.
It's this "Weigan" standard that I'm trying to get a hold of
Thanks for your interest
Kenneth
A few months ago I succesfully implemented a wiegand interface for a PIC
16C57. It now makes part of a commercial reader, so I am not allowed to
give you my sources... but I can help you with a short description of the
magstripe protocol.
---- Introduction
Here follows a short description of the magstripe or Wiegand protocol
that is used by many magnetic card readers.
8 8 0 1 0 0 0 -
9 9 1 1 0 0 1 -
- A - - - - - Not used.
< SS > B 0 1 0 1 1 Start Sentinel.
- C - - - - - Not used.
< FS > D 0 1 1 0 1 Field Separator.
- E - - - - - Not used.
< ES > F 1 1 1 1 1 End Sentinel.
< LRC > x x x x x x Longitudinal Redundancy Check.
---- Notes:
1. In fact the magstripe protocol is an extended version of BCD coding.
2. Every symbol exist of 5 bits: 1 parity bit and 4 data bits ( p
and b3...b0). The parity bit should be chosen in such a way
that an odd number of '1' bits appears in the symbol.
3. < SS > marks the start of the data.
4. < FS > separates two information fields.
5. < ES > marks the end of the data and precedes < LRC >.
6. Every symbol should be transmitted as: b0 - b1 - b2 - b3 - p
(least significant bit first).
---- Longitudinal Redundancy Check
The Longitudinal Redundancy Check is an error detection code and
also the last symbol to be transmitted directly after < ES >.
The value of < LRC > (1 parity bit and 4 data bits) must be
chosen in such a way that an even number of '1' bits appears on
corresponding bit positions (b3...b0) of all transmitted symbols
together (the data symbols plus < SS >, < FS >, < ES > and < LRC >
symbols). The parity bit (p) of < LRC > must be chosen in
such a way that an odd number of '1' bits in < LRC > itself appears.
---- Data stream
The data stream can be described as follows:
< SS > N N N ... < FS > ... N N N < ES > < LRC >
with 'N N N ... N N N' representing the data symbols (decimal digits).
---- Output format
The Wiegand protocol uses an two wire output formaat that is called
'clock and data output':
Setup time before Clock tsu 100 us
Clock time tck 100 us
Hold time after Clock thd 100 us
Clock repetition tnx 1000 us
Note:
Above timing is used by many commercial magnetic card readers.
There might be some variation in timing for reason that manually
'swiping' a card through a reader will never occur at the same
(or a predefined) speed! Most equipment to which a magnetic card reader is
connected will accept signals that come twice as fast or twice
as slow as I mentioned above.
Clock and Data should return to 'logic zero state' (+5V) between
consecutive bits.
At 07:55 AM 22/03/96 +0100, Arthur van Deursen wrote:
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>At 14:25 14-03-96 +0800, you wrote:
>>Does anyone have knowledge of any standards for Magnetic Key Readers?
>Well, I'll give it a try.
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>A few months ago I succesfully implemented a wiegand interface for a PIC
>16C57. It now makes part of a commercial reader, so I am not allowed to
>give you my sources... but I can help you with a short description of the
>magstripe protocol.
>=====================_827474146==_
>------------------------------------------------------------
>Arthur J.H. van Deursen
Thanks Arthur;
My original question related to magnetic Keys.
These keys have four or five rows of magnet slots transversally across the
key, molded into the inside.
------------- end of key
X X X X first row
X X X X second row
X X X X third row
X X X X last row
Each row has four magnet slots, (sometimes on both sides, making a possible
combination of 8 data bits per row. The keys I have in my possession have
magnets on only one side)
A data bit of "1" has a magnet present inside the key, and a "0" has no magnet.
1 1 0 1
1 1 1 1
0 0 0 1
0 1 1 0
The Key interrupts one of five I.R. leds which cues the processor to poll
for a magnetic reading (via hall effect switches) The first led near the
entrance of the key slot, when interrupted, tells the processor: wake up,
there is a key present. The 2nd,3rd,4th & 5th is so placed as to indicate
to the PIC that the magnets should now be over the Hall Effects, and a
reading should be made. After all data is read in, it is comared with data
set by two 8 bit dip switches.
If the dip switch and key data match, a two- wire wiegnand protocol is
initiated to interface with a mainframe or mother processor and, provided
data is acceptable, the door is unlatched.
I 'd like to know how ( in what format) this verify data is sent over the
two lilnes, and if it is a standard format.
If it's not a standard, I'd probably have to get ,hold of an actual working
unit and try to extract the info. with a CRO or data analyser (not, I think,
an easy task)
Any suggestions would be appreciated.
At 21:12 24-03-96 +1000, you wrote:
>I 'd like to know how ( in what format) this verify data is sent over the
>two lilnes, and if it is a standard format.
>If it's not a standard, I'd probably have to get ,hold of an actual working
>unit and try to extract the info. with a CRO or data analyser (not, I think,
>an easy task)
>Any suggestions would be appreciated.
>
>Cheers,
>K.ParkynKILLspamsct.gu.edu.au (Ken Parkyn)
>
At this moment I don't have any information about Magnetic Key Readers; the
Wiegand interface I build was ment as an interface between an access control
system and a chipcard reader.
Maybe the manufacturer of the Magnetic Key Reader that you wish to improve
can provide you with some product information? In the documentation of most
commercial readers there is a chapter about data communications and formats.
This would be the most easiest way to find out...
However, if you can tell me the name of the manufacturer and the type number
of the device, I'll try to find out.
Greetings, Arthur
------------------------------------------------------------
Arthur J.H. van Deursen
ITsec Nederland B.V.
P.O. Box 703
2003 RS HAARLEM
The Netherlands
At 21:12 24-03-96 +1000, you wrote:
>I 'd like to know how ( in what format) this verify data is sent over the
>two lilnes, and if it is a standard format.
>If it's not a standard, I'd probably have to get ,hold of an actual working
>unit and try to extract the info. with a CRO or data analyser (not, I think,
>an easy task)
>Any suggestions would be appreciated.
>
>Cheers,
>EraseMEK.Parkynspam_OUTTakeThisOuTsct.gu.edu.au (Ken Parkyn)
>
At this moment I don't have any information about Magnetic Key Readers; the
Wiegand interface I build was ment as an interface between an access control
system and a chipcard reader.
Maybe the manufacturer of the Magnetic Key Reader that you wish to improve
can provide you with some product information? In the documentation of most
commercial readers there is a chapter about data communications and formats.
This would be the most easiest way to find out...
However, if you can tell me the name of the manufacturer and the type number
of the device, I'll try to find out.
Greetings, Arthur
------------------------------------------------------------
Arthur J.H. van Deursen
ITsec Nederland B.V.
P.O. Box 703
2003 RS HAARLEM
The Netherlands
ITsec.nl>