User`s manual
43
Transmission Retries and Device Inactivity
A remote device is considered inactive if a certain number of sequential transmissions to
that device fail (see “ZDO_Device_Manager.max_sequential_TX_failures” on page 46).
When a remote device is marked as inactive, clusters on the gateway will be informed
that any matching clusters on the remote device are no longer available.
SE Server Clusters and Inactive Devices
If an SE server cluster on the gateway is notified that a client cluster has been removed,
that client cluster will be removed from the list of known SE client clusters for that
particular SE server cluster. Events which are missed by the remote device while it is
inactive will be sent when that device becomes active again.
Periodic Refresh
In order to keep network information up to date, refresh messages are sent periodically
(see “ZDO_Device_Manager.refresh_rate” on page 46). These are in the form of Match
Descriptor broadcast requests for the SE Key Establishment cluster server (0x0800).
Devices which do not respond within the timeout period will be considered to have a
transmission failure (see “Conversation.TX_status_timeout” on page 45).
In this manner, active devices which have dropped off the network or otherwise become
unable to receive transmissions (interference, power loss, etc), will be marked as
inactive even if no user-initiated communication to that device has taken place. Devices
currently marked as inactive will be marked as active if they respond to the broadcast.
Explicit Device Add and Open Join
The gateway can be in either open join or explicit device add mode. When in open join
mode, any device can become active. Devices that become active will be added to the
list of known devices (see “Device Detection” on page 42). When in explicit device add
mode, only devices which have previously been added as known devices can become
active. In either mode, devices can be added to the list of known devices by using the
add_device command (
see “add_device_response Parameters:” on page 73).
The gateway defaults to open join mode.
(See “ZDO_Device_Manager.require_explicit_device_add” on page 47.)