Configuring inputs and outputs

The Accessia platform allows you to configure polarity of both inputs and outputs in either software on the Cloud Converter, or in hardware on the AI Security Hub. When connecting to relay outputs, you can choose between using the NC or NO output.

Input devices such as door position sensors and exit buttons are available in either NC or NO versions, or feature both NC and NO outputs.

Locks are available in different types such as maglocks, which require power to lock the door, or electric strikes, which can require power to lock the door (fail safe), or power to open the door (fail secure).

Reading and understanding this document will help you wire and configure your access control system for proper functionality.

Choosing the right wiring options and software configuration is essential to ensure compatibility with the chosen hardware and for correct functioning in cases of broken cables or power loss etc.

Inputs

Door position sensors

Usually, the 'normal' state of a door is considered to be in the secure state, i.e. with the door closed. This might not match the wording shown on the output of the sensor, for example:

  • For a reed switch type contact, the normal state would be with the door open

  • For a maglock field strength sensor, normal is typically when the maglock is not energized, for example when the door is open and unlocked

Other inputs

For a button, the normal state is when the button is not pressed. Understanding this helps with the below:

  • For a REX button, typically the button offers NC and NO outputs. Usual configuration is to connect the NO output into the input on the controller, and choose the option Door release request closes circuit (NO)

  • For a presence detector, the sensible option is Presence detection closes circuit (NO). This ensures that, if a presence detector fails (for example, in the case that even when people are present, the input stays open), all door openings will result in an alert. This might be the opposite of typical usage of a PIR sensor in an alarm sensor, where it is desirable for a cable break to trigger the alarm, so Presence detection opens circuit (NC) would be used

  • For an emergency door release, usual setup is that a failure in the emergency door release mechanism, or a break in the cabling connecting the emergency door release to the controller, will result in the door being released. To enable this, use the NC output of the emergency door release, and choose the Emergency door release opens circuit (NC) option. This way a break in the cable will cause an open circuit to appear to the input, and so trigger the door to open

  • For a door position indicator, the active state should be when the door is open. Therefore, if the sensor is installed such that closing the door closes the circuit, choose the Circuit is closed when door is closed (NC) option.

Outputs

To correctly choose how to connect the output, consider the type of lock and the desired behavior in case of a controller failure, as might be caused by hardware failure or complete loss of power including exhaustion of the backup battery.

To control the behavior of the relay in case of controller failure, use the software control of the output polarity. If, in the case of a failure, the lock should open (fail safe), the Energize relay on lock option should be used. On the other hand, if in the case of a failure the lock should lock (fail secure), the Energize relay on open option should be used.

Note that fail secure locks can trap people during a power outage or failure. Install a mechanical exit mechanism to ensure people can safely exit at all times

Cloud Converter for S2 Netbox outputs

When using the relay outputs, three terminals are available, NC, NO, and COM. For all installations, COM and one of either NC or NO should be used. To choose whether to use NO or NC, consider the software option, and the type of lock

Lock requires power to lock (e.g. maglock)

Lock requires power to unlock (e.g. electric strike)

Energize relay on lock (fail safe)

COM & NO

COM & NC

Energize relay on open (fail secure)

COM & NC

COM & NO

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