User guide

Silicon Labs Page of 13 21
Attribute Description
_writeencrypted
This attribute defines that writing the characteristic value over a connection Bluetooth
requires that the connection is encrypted. With iOS 9.1 and newer, devices must also
be bonded at least with Just Works pairing. This attribute is only valid with the
Bluetooth stack in the BT121.
NOTE! Attribute must also be set to . or write write_no_response "true"
encrypted_notify
This attribute defines that Notifications and Indications require the connection to be
encrypted. This attribute is only valid with the Bluetooth stack in the BT121. With iOS
9.1 and newer, devices must also be bonded at least with Just Works pairing. This
attribute is only valid with the Bluetooth stack in the BT121.
NOTE! Attribute must also be set to . or notify indicate "true"
reliable_write
This attribute defines that reliable write procedures to modify attributes are allowed.
This is just to inform the GATT client of this possibility. The stack always allows using
reliable writes to modify attributes.