Support of battery-powered Z-Wave devices requires special considerations. These devices “sleep” the majority of the time, “waking up” on a defined interval, or when the device detects an event.

As previously mentioned, to properly support battery-powered nodes, the JACE should be configured as an SUC or SIS. This will keep the JACE’s Z-Wave interface node ID from changing. It also allows notification when a Z-Wave device has been installed on the network. The JACE can “discover” a battery-powered device when it is installed, since it is in an awake state at that time.

The “Wake Up” command class of a battery-powered device is configured with the node ID of the device that it will send wake-up notifications. If the JACE is configured as an SUC or SIS, the node ID of the JACE’s Z-Wave interface is used—otherwise, a Z-Wave broadcast address is used.

If the battery-powered device also supports associations, the driver automatically adds the JACE to the devices’ association groups. Typically, this causes the JACE to be notified via the “Basic” command class report when the device detects an event.

There seems to be some inconsistency between vendors and devices in the way battery-powered devices react when they detect an event. Some devices send a Wake Up command class wake up notification message, while others only send a Basic command class report to the association group members.

The Z-Wave driver does support posting changes to the Configuration and Associations command classes, so that those changes will be processed on the next wake up. Other command classes that the battery-powered device may also support require a coordinated manual wake up of the device, prior to making changes.

The “Naming” command class is an example. If you wish to change the Z-Wave name or location of a battery-powered device, it requires that the device is awake when you make the change.

When the driver evaluates a device as asleep, it sets the device's stale flag. When the device is detected as awake, the stale flag is cleared.

The driver does not ping the device to determine device up/down status. Its down flag will never be set, unless the device also implements the WakeUp command class. If it does, the device is marked down only if a WakeUp Notification message is not received at the interval specified in its WakeUp command class.