2.2.4.4.3 Transparent Control Point (TCP) Characteristic

Before performing a Transparent Control Point procedure, the Transparent Client shall configure the Transparent Control Point (TCP) characteristic for notifications (i.e., via the Client Characteristic Configuration descriptor).

When Transparent Client prepares to send data to Transparent Server, the Transparent Client shall write a Characteristic Value to the Transparent Control Point Characteristic. The Transparent Server might respond it with a notification by Response Code that may include the Request opcode and might also include a Response Parameter as defined in [1].

When Transparent Server prepares to send data to Transparent Client, the Transparent Server shall perform a notification with a Characteristic Value to the Transparent Control Point Characteristic.

Table 4.4 shows the requirements for the TCP opcodes in the context of this profile:

Table 4.4: TCP Op Code Requirements
TCP Opcode	Requirement
Response Code (0x00 ~ 0x03).	Mandatory.
Downlink Credit Based Flow Control Enable (0x14).	Mandatory if the Downlink Credit Based Flow Control is supported.
Uplink Credit Based Flow Control Enable (0x15).	Mandatory if the Uplink Credit Based Flow Control is supported.