Cansec Blog

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Active Presence Reader - Machine Control


There is a rapidly growing emphasis on workplace safety being driven by regulatory bodies such as OSHA in the USA and the Canada Labour Code. In addition, the introduction of Bill C-45 in Canada established new legal duties for workplace health and safety, and imposes serious penalties for violations that result in injuries or death.

The unrestricted use of dangerous machinery on the shop floor constitutes a significant liability issue for employers as evidenced by a $190K fine paid by Walmart in August 2013 for, amongst other things, “unsafe trash compactor procedures”. Under the settlement, trash compactors must remain locked while not in use, and may not be operated except under the supervision of a trained manager or other trained, designated monitor.

Clearly, hanging a sign on a piece of dangerous shop floor equipment which says “To be used by authorized personnel only” is not adequate.

Access systems have been used for many years to manage physical access to restricted areas. However, they can also provide a cost effective means of insuring that dangerous machinery is only used by trained and authorized operators.



Access control systems are designed to unlock doors, gates or other physical barriers by momentarily activating a relay. The relay remains activated for a fixed interval (i.e. 5, 7, 10 seconds). This works fine for doors, gates, etc. but it does not work well when the item being controlled is a piece of machinery.

Obviously the momentary relay output from the access control panel can be used to activate the equipment for a fixed and pre-programmed period (i.e. 5, 10, 30 minutes) but what deactivates it? If the activation period is too short, the operator has to keep presenting their access card to “buy more time”. If the activation period is too long, the machine will be left activated (and unattended) should the operator leave before the activation period expires.


What is needed is a way to have the operator's card “clip” onto the reader and remain there as long as the operator is working on the machine. The machine should remain activated as long as the card is present. When it is removed, the machine should be immediately deactivated.

This solution is implemented with a product developed by Cansec Systems Ltd. called the Active Presence Reader.

This solution consists of a Cansec CanProx One reader with a built-in card clip and an Active Presence Reader control module. The CanProx reader contains firmware which continuously reads the card and outputs Wiegand data to the control module.

The control module has two Wiegand ports and an onboard Machine Control Relay which is used to activate/deactivate the controlled machine.

When a card is snapped into the reader clip, the following occurs:

1.    The card data is sent to the control module.
2.    The control module sends the data to the connected access control panel and monitors the access control panel’s lock output relay.
3.    If the lock relay is activated, the control module knows the cardholder is authorized to use the machine at which the card was presented and turns on its Machine Control Relay.
4.    The control module monitors the Wiegand data constantly being sent by the reader.  When the access card is removed from the clip, the control module turns off its Machine Control Relay and sends the Wiegand data (for the card just removed) to the connected access control panel.

Besides providing control of the machine, the host PC will have two transactions in its audit trail file - one when the machine was activated and one when it was deactivated. With the appropriate reporting software, this allows a report to be generated of machine utilization by operator.

Another application for the Active Presence Reader is controlling lighting. Only specific authorized users would be allowed to turn on the lights. When their card is removed the lights are turned out. The ON event and OFF event are both recorded in the access control audit file allowing users to be charged for their usage. This is very handy in a commercial multi-tenant high rise.

The Active Presence Reader is compatible with all access control panels and all 125kHz HID or HID-compatible access cards regardless of their Wiegand format.

Emergency Lockdown



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