What is a Proximity Card Time Clock

In Time and Attendance systems time clocks can be equipped with a variety of card readers. If we go back more than 5 years ago bar-code cards were not unusual but in today's market the Radio Frequency Identification Device (RFID) has become the preferred technology . Most of  these RFID devices are the passive type consisting of a chip containing a small integrated circuit used for storing and processing information and and a tuned antenna fro receiving and transmitting data. When an external transmitter is near the RFID tag it become active more or less powered by the external antenna.

RFID devices are fitted to an increasing number of products particularly in the security industry. They are used to protect goods in retail outlets, they are fitted to consumables in printers to ensure that genuine ink cartridges are used, the are used in access control applications to open doors. They are extensively used in the time and attendance industry where employees carry an RFID card or tag to clock in and out each day. The common name for these devices is a proximity time clock or RFID time clock.

Most end users would agree that RFID cards are simple to use, almost indestructible, safe, relatively inexpensive reliable and very convenient. They do however, come in a range of formats which generally do not impact performance but they do impact cost, cross application compatibility, ease of use and availability. Formats include proprietary offerings which are only available form certain manufacturers such has HID and Indala  and some which use an international standard such as the Mifare Smart-card.

When you are considering a time and attendance system for you business the product you use may be impacted by your current or intended use of security and access control systems . Your new time and attendance system should use RFID cards that are either compatible with your existing security system or it should use one of the more easily accessible RFID card systems.

It is almost certain that you will be able to find a time and attendance supplier using the same RFID Technology but you are more likely to find it an easier task if you are using an HID (who also make a mifare product) or Indala system. Because there are multiple options within the same technology provider  you will need to provide the time and attendance provider with a sample of your card to make sure their equipment can read the card. Once they have established suitability you can be confident that the systems will be able to use existing cards or tags which is both a convenience and a cost saving

If your security provider uses Mifare cards this will make the choice of time and attendance provider more complex due to the programmable nature of Mifare cards. Mifare cards are formatted with a number of programmable sectors depending on the memory capacity of the card. These sectors require a special secure electronic key to open and encode the sector and also to read that sector again. This is where the compatibility issues start. Your supplier of time and attendance will have to be able to specify the sector to which it writes and you current cards must be of sufficient capacity to take the encoded information for both the security and time and attendance systems . Unless your both applications are from the same provider they will not be able to access any sector encoded by the others hardware. If your applications are form different suppliers it is almost certain that they will not be able to access each others hardware.

Mifare cards are the new standard and their flexibility is certainly an advantage. You can encode quite a lot of information on a Mifare Card. In a recent application my colleagues facilitated the process of including staff time and attendance, security access control, car parking station access, canteen credit and employees medical records data on the same card in a large metropolitan hospital.

If you intend using and RFID solution for your time and attendance and this is the only current business system using this this technology, you canlt go too far wrong with HID or Indala . You will certainly be able to add access control later and not get caught out with odd standard. You may also use Mifare Card but you would be wise to opt for one of the larger memory sizes such as 4K to allow for expansion to other products.

The last factor to discuss is the cost of these technologies. While none of the  RFID technologies is expensive to produce there can be quite a significant variation in cost. HID  and Indala tend to be more expensive and it is rare to see much variation in price from your solution provider because their cost is fixed. Mifare cards by comparison are generally purchased unencoded at a very low price and then encoded by the solution provider and this provides a greater degree of flexibility.

One final tip...the price of the cards you buy will almost certainly go up once you have purchased the system. The salesman will almost certainly give some away to secure the sale so  negotiate for additional cards of tags when you purchase and you will save yourself hundreds of dollars in a very short time.

James Bell

Time and Attendance Consultant

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