Communication - System description WO

Each GatewayNode in WaveNet expands its own segment and manages LockNodes within its segment. The WaveNet quality guidelines stipulate a maximum of 16 LockNodes per GatewayNode. A maximum of two repeaters (SI.GN.R) are permitted per wired (Ethernet/RS-485) (see GatewayNode radio radio).

Communication between GatewayNode and LockNode is limited to one active communication per segment. A GatewayNode can therefore only communicate with one LockNode at a time. During this communication, no other communication between the GatewayNode and another LockNode can take place in this segment.

All communication is event-based. If there is nothing to share, then no connection is established either.

GatewayNodes, whose radio ranges overlap, so-called overlapping segments (crosstalk), are also affected by this.

Communication between GatewayNode and LockNode for engaging usually takes a maximum of 500 ms. As a result of this short duration, limiting the connection to a maximum of one active connection is normally not a problem. Larger processes such as extensive programming of locking device configurations (e.g. after updating a whitelist with many entries) can reduce the available bandwidth in WaveNet and lead to temporary disruptions. The integrator system is responsible for sequential processing here.

All components use a list-before-talk procedure. Before sending, the components always check first whether communication is currently taking place within their segment.

  • A new communication is only established if no communication is currently taking place in the segment (i.e. the segment is free).
  • If communication is ongoing in the segment (i.e. the segment is not free), the component waits and tries to send the data packet up to three times. After the third unsuccessful attempt, the data packet is discarded.

There are three types of communication between the integrator system and LockNode:

  1. LockNode to GatewayNode: Events (e.g. reading the card)
  2. GatewayNode to LockNode: Commands (e.g. engage locking device)
  3. LockNode to GatewayNode: Answers to commands (e.g. successful or why not successful)

In order to extend the battery life of battery-operated locking devices, the following components of the locking device are always in standby mode:

  • Card reader
  • LockNode

They only become active when they are needed. The LockNode checks every three seconds for a very short time whether a GatewayNode is currently trying to communicate with it. The frequency of these tests can be adjusted (see Shorter LockNode response times (short wake-up period)).

Example: A user opens a door with their card

Event

  1. A user holds their card in front of the locking device.
  2. The locking device registers an event.
  3. The locking device immediately activates the LockNode.
  4. The LockNode sends the event immediately via WaveNet.
  5. The LockNode remains active for a few seconds in order to receive commands from the integrator system.

Command

  1. The integrator system receives the event via WaveNet.
  2. The integrator system decides on the opening.
  3. The integrator system sends an opening command via WaveNet to the LockNode of the locking device.

Answer

  1. The LockNode receives the opening command via WaveNet and forwards the opening command to its locking device.
  2. The locking device will engage.
  3. The locking device transmits the result of executing the command to the integrator system via its LockNode and WaveNet.

Example: A is opened without an event (e.g. remote opening from the integrator system)

Command

  1. The integrator system sends an opening command to the lock.
  2. The corresponding GatewayNode attempts to establish contact with the locking device LockNode for a maximum of 12 seconds.
  3. (Wake-up signal with interruptions according to 868 MHz specifications)

Answer

  1. The LockNode checks every three seconds (adjustable) whether a GatewayNode is currently contacting it.
  2. The LockNode receives the opening command from the GatewayNode and forwards it to its locking device.
  3. The locking device will engage.
  4. The locking device transmits the result of executing the command to the integrator system via its LockNode and WaveNet.

It may take up to twelve seconds between sending a command that comes directly from the integrator system and not responding to an event at the locking device and the corresponding response at the locking device. In a few cases (high frequency utilisation, faults), several attempts may be necessary until a command arrives at the locking device. This process is controlled by the integrator system.