User's Manual

This command is effective only if the handle is valid in server service. Characteristic
in server service is always writable regardless of its property. Characteristic
property is only for remote access. The content of a configuration handle, which
starts or stops notification/indication, is usually set remotely. We highly
recommend not writing to configuration handle, although such operation is not
prohibited.
When Buffered Read feature (See section 3.2.1.12 for command “SR”) is not enabled,
RN4020 requests content of a characteristic from the host MCU, when receiving
read request from the remote device. The host MCU needs to use command “SHW”
or “SUW” to write the content and therefore responds to the request.
When command “SHW” is issued to change the local content of characteristic, a
notification or indication might be send to remote device, if following conditions are
met:
 An active connection exists
 Remote device support the corresponding service and characteristic as client
role
 Property of corresponding characteristic supports notification or indication
 Notification or indication service for the corresponding characteristic has been
started by the remote device
Example: SHW,001A,64 // Set local value of characteristic Battery
// Level with value handle 0x001A to be
// 100%. If notification service has been
// started on Battery Level before, local
// device will notify the new value of
// 100% to the remote peer device
3.3.3.12 SUR
According to command interpolation method described in section 3.3.3.1, command
“SUR” reads value of characteristic in server service on local device by addressing its
UUID.
The parameter of command “SUR” is hex value of the UUID of a characteristic. The
UUID could be either 16-bit short UUID for public characteristic, or 128bit long
UUID for private characteristic.
This command can only read value of a characteristic. Generally speaking,
configuration of a characteristic in server service is accessed remotely by peer
device. Therefore local device does not care about the setting. If user needs to know