Which Keypads Support Wiegand?

Hi guys,

i m looking for information on keypad reader data format sends over wiegand interface.

is there any industry standard data formats among different manufacturer's pinpad reader ?

How can any pin pad wiegand reader works with varies Access control platform ?

The good news is a device like this is pretty common in access. Take any of HID's "K" variant readers, for example. There are many more examples.

They all feature the ability of converting a PIN to a 26-bit Wiegand string:

In terms of how/why Wiegand is widely supported by various platforms, the answer is: it is very simple. Two wires carry small amounts of voltage, and when that voltage drops on a particular wire (either '0' or '1'), a bit is registered by the controller. It is not bidirectional (only sends from reader to controller), nor encrypted, nor particularly quick compared to more advanced protocols (like TCP).

It really is the simplest method of digital communication, and for small data sets like credentials or PINs, it works fast enough to be satisfactory.

Wiegand is the most general standard protocol, although 'Clock & Data' and OSDP might also be used in a similar way if supported by both reader & controller.

Many keypads readers designed for electronic access control include a Wiegand interface, and communicate via various Wiegand modes. These Wiegand modes allow the keypad readers to communicate with many standard electronic access control systems.

I'm not familiar with any one standard data format for keypad readers, through three of the more common Wiegand modes include:

8-bit Burst (aka Dorado output);

26-bit Wiegand;

and 4-bit Wiegand.

Here's a document you may find interesting in regards to these modes: http://www.farpointedata.com/datasheets/qsg_and_ref/KeypadMode_REF.pdf.

Hope this is helpful.

Thanks Scott and Brian...

It means Access control systems and keypad reader have Pre-configured data format for proper data transfer right ?

4 bit burst/8bit burst and 26bit wiegand are formats for keypad reader. same can be support by EAC system too for proper functioning of reader with EAC.

any EAC system which support different keypad reader format ?

Yes, you are correct. The protocol between the keypad reader and the electronic access control system is normally pre-configured for proper data transfer. Typically, today this will be Wiegand. Note that the term ‘Wiegand’ has broad meaning. It may be used to refer to cabling requirements, the electrical inferface of a device, or the structure of the data messaging.

Not certain of the specific PACS that support them, but in addition to Wiegand, keypads are available with many different interfaces. A few of these interfaces include ABA Track II magnetic stripe, serial, and matrix. This link includes a good listing under ‘OUTPUTS’: http://www.keyless.com/PDF/KTP.pdf.


the interface between keypad reader and EAC panel is mostly wiegand only. (at least in my case)

Do you know detail on the format of data transfer over wiegand interface of entered pin with below popular formats:

4 bit word style

8-bit word-style

26 bit wiegand

Hi Sundar-

Indeed, my experience shows the interface between keypad readers and EAC panels is indeed mostly Wiegand.

For specific details on the format of data transferred over the Wiegand interface when a PIN is entered, I recommend you download the reference document obtained by following this link: http://www.farpointedata.com/datasheets/qsg_and_ref/KeypadMode_REF.pdf.

A couple of extraneous points:

4-bit word style: common with many HID readers;

8-bit word style: widely supported and follows the legacy Dorodo PIN output;

26-bit Wiegand: a catch all for situations where the 4-bit or 8-bit word styles are not supported. Limitation is PIN length (five characters/digits), as this is typically represented by the 16-bit ID field.

Hope this is what you are looking for. If you still have questions, please feel free to give me a call.



Thanks Scott...

also found one useful link for keypad format details:


what i understand is Most keypad reader comes under 4bit word, 8bit burst and 26bit wiegand format ?

as i seen many keypad reader manufacturer are not mentioning the keypad format details in their datasheets.

Thanks Sundar for the worthwhile link. And your understanding is the same as mine, that most keypad readers come in either the 4-bit word, 8-bit buts or 26-bit Wiegand format.


again few queries relevant to wiegand PIN pad reader.

i have one wiegand based reader which supoort PIN and RFID card (Iclass). It works fine in only PIN mode or only CARD mode when i connect over wiegand to EAC controller. But, I don't understand how can i make work for CARD + PIN (both) mode in same setup.

this should be wiegand reader's functionality to verify CARD + pIN credential locally once and then only sent it to EAC controller ? (i guess reader has no memory or such function)


Yes Sundar, I do know that some CARD+PIN readers do indeed offer the functionality of verifying a credential (card) with a PIN. Specifically what I've seen is that a PIN is associated with a specific credential. In operation a user presents a credential to a multi-factor reader, for example a reader combining card read and keypad functionality. Next, the user enters a PIN into the reader's keypad. If the PIN is correct, then the multi-factor reader will output the credential data to the EAC controller. If the PIN is not correct, then the multi-factor will not output the credential data.

I can't tell you if HID, manufacturer of Iclass products, or Rosslare, offer this specific functionality. Best to check directly with them.

The old HID Biopass fingerprint readers worked like this; they used a biometric template stored on the card as a 'check' - the card was scanned, and if the fingerprint on the reader matched the card template, the credential data was sent via Wiegand to the controller.

However, this approach requires either a special card storing data, or a special reader to provide this logic at the reader alone.

The Rosslare part number Sundar is posting does not have this feature, and there is no storage for PINs or Card numbers on board the reader at all. In this case, Sundar's access system needs to support Card+Pin functionality, as having a dual factor reader alone is not enough.

As everyone points out, many keypads support wiegand. An excellent choice is Essex. I have been using it for 30 years. Good Luck.