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Driver ID Options [G120]

The G120 supports a variety of Driver ID options to provide driver behaviour monitoring, access control and logbooking solutions.

If a worksite already has a specific reader or card type in use – chances are one of our devices will be able to read it, enabling a variety of unique, cost effective options, and removing the hassle of reissuing ID cards! There are even keypad options for those that prefer this ID type.

Driver ID Interfaces

The G120 has the following interfaces to support various readers:

This interface is used on the G120 with the DM RFID reader. The G120 harness has a 5V output which powers this reader. 
iButton (1-wire)
Common interface, a wide variety of readers are available
Common access control interface - wide variety of readers available
Can be used with any readers that output RS232 - integration required. Generally Wiegand or iButton readers can be sourced which will work without FW integration.
TTL - DM RFID Reader

Reads DM Supplied 125kHz EM4001 fobs. On the G120, it simply plugs in. This makes for a convenient out of box solution. 

  • Contains an internal buzzer for in-cab feedback
    • Buzz if a driver hasn't tagged on as a reminder
    • Buzz on overspeed
    • Buzz on harsh events
    • Many other options

Manufactured by Maxim/Dallas Semiconductor, an iButton is a microchip housed in a round stainless steel button (it looks a bit like a coin cell battery). iButtons and their readers require physical contact to function, but they are cheap, rugged and effective.  

Digital Matter stock and supply iButton tags and iButton readers. But a variety of 3rd party readers can be sourced to suit other requirements.

iButton readers send their data over a 1-wire interface, developed by Dallas for the tag format. However, it does not mean only iButton tags can be read over 1-wire. In fact, a multitude of readers can be sourced that will read a variety of cards and connect to the 1-wire input on our devices.

These card types include: MiFare, EM4001 125kHz and HID cards.


The Wiegand Interface is a wiring standard found on card readers and access control systems. It has become somewhat of a de facto standard for such systems.

Wiegand initially caught on in the 1980s due to its ability to support far longer cable runs than other standards at the time. Wiegand swipe cards also do not contain microchips and cannot be magnetically erased, making them durable.

Newer standards have since developed, and you do not see many Wiegand cards in use anymore. However, while the actual swipe card may use a different protocol, many readers have a Wiegand output which is used to send the data to other devices or control systems. 


The G120 also has an RS 232 interface. RS232 is a serial interface used for the transmission of data. Any readers that output RS232 can be potentially integrated with the G120, however Firmware work needs to be undertaken. This provides another driver ID option. 

Typically if a certain type of card is required to be read, a Wiegand or 1-Wire compatible reader can be sourced which is the preferred option due to its plug and play nature. 

Driver ID Card/Fob Types

Common ID types include:

  • EM4001 125kHz cards (ready by DM RFID reader and fobs supplied by DM)
  • MiFare
  • HID
  • iButton

What does this mean in practice? 

Many companies utilise swipe cards for their employees to grant them access to buildings, vehicles, or equipment. A large site may have hundreds of employees with swipe cards already issued.  

When rolling out tracking devices into their vehicles, Driver ID is often key requirement.

While the DM RFID reader is a simple and effective solution in terms of installation and setup – it may require the company to issue and maintain another RFID Fob – which can be quite a task.  

To simplify the solution, a suitable reader that reads the swipe cards already issued and has a Wiegand or 1-wire interface can be sourced. Such readers can work with our devices, meaning the current cards can still be used! 

So how do I work out what reader to get? 

  1. Find out the format of the access cards – the reader must read these. 
  2. Search for readers that read this type of card and check their datasheet to see whether they have a Wiegand or 1-wire output.
  3. Select one that is reliable, a suitable price and form factor.
  4. Connect this reader to the G120.

Example, searching for readers - we could apply these filters on a site stocking readers when trying to find a solution to reading HID cards.

HID is the tag we need to read, and to read this with the G120, we can use the 1-Wire interface.

Powering the Reader

We also need to consider how the reader will be powered. Typically iButton readers don't need to be externally powered and operate off the 1-wire interface alone. Check the voltage spec on the reader to see if it makes sense for your application.

List of Driver ID readers and solutions

The below is a list of reader solutions which we have come across to read a given card type. Not all are thoroughly tested by DM, resellers should conduct their own testing to ensure the performance is satisfactory. Additionally this list is not exhaustive, there are many solutions available on the market to fulfil various needs.

iButton Tags
EM4001 RFID Tags
HID Cards

HID Global is a manufacturer of security and access control products. Their cards and readers are commonly used in buildings and worksites. 

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