ANSI/CTA-2017.1:2007 pdf download.Serial Communication Protocol for Portable Electronic Devices.
3.2.1 Function Blocks
FBlocklD identifies a function block. A function block is a group of functions for a device. A single device may have multiple components and therefore multiple function blocks. FBlocklD consists of 8 bits, and has a limit of 255 maximum number of function blocks.
3.2.2 Functions
FktlD identifies a specific function within a device that can be called via the serial protocol. FktlD Consists of 12 bits, but each function block has a limit of 508 maximum number of functions. The range of FktlDs is subdivided into groups that have specific purposes. The subdivision of FictIDs is as follows:
• General Functions (0… 9FFh) General functions in an function block
• Player Specific Proprietary Functions (AOOh. . FFEh)
o Proprietary functions that the portable electronic device manufacturer may use
• Accessory Specific Proprietary Functions (AOOh.. . FFEh)
Proprietary functions that the portable electronic device accessory manufacturer may use
• ProprietaryISupplier Specific (FOOh. . . FFEh)
o Functions that may be used by suppliers for any poprietary purpose. Supplier specific functions are not reported in FBlocklD.FktlDs.Status. If a supplier specific property supports notification, notification of this property is not affected by the FBlocklD.NotiIication.Set (SetAll) command. If a supplier specific property supports notification, notification of this property is cleared by the FBlocklD.Notification.Set (ClearAll) command.
3.2.3 Function Operations
When accessing functions, certain operations are applied to the respective function which is either a property of the function block or a method it provides. The type of operation is specified by the OPType. The parameters of the operation follow the OPType, resulting in the following structure:
FBlocklD.FktlD.OPType(Data)
OPType identifies the operation that shall be applied to the property or method specified in the FktlD,
A property is a segment of computer code that may be used to read and write data, and is frequently used to set or get method calls.
A method is a segment of computer code that performs an action, and may include a set of input parameters that customizes the action and an output value.
The meaning of the OPType value is different depending on whether FktlD is a property or a method. OPType consists of 4 bits, so each function may have up to 16 OPType values. The possible meanings for the various OPType values are listed in Table 1.
3.2.3.1 Function Types
A function is a defined attribute of a function block through which it communicates with the external world.
Functions are subdivided into three classes, methods, ‘properties”, and “events”.
3.2.3.2 Method Function Type
Functions that can be started and which lead to a result after a certain period of time, are called “methods”.
Methods can be used to control function blocks. In general, a method is triggered only once at a certain point of time, for example, starting the auto-scanning of a tuner. Methods can be defined without parameters or with certain parameters that specify their behavior.
After the reception of a method called by a function block, the respective process must be started. If this is not possible, the function block has to return the respective error message to the sender of the method call. This may happen if the addressed function block has no method of that kind, it a wrong parameter was found, or if the current status of the function block prevents execution of the method.
After finishing the process, the controlled function block should report execution to the HDEV. This report may contain results of the process. If a process runs for a long time, it may be useful to return intermediate results before finishing, such as informing the HDEV about the successful start of the process.
3.2.3.3 Property Function Type
Functions for determining or changing the status of a device, which refer to the current properties of a device are called “properties”.
