The Command ANSI-C API provides a backward compatible thread-safe Command API for user developed programs originally written for TReK Release 3.x. The API is provided to allow user applications that integrated TReK 3.x APIs an easy path to upgrade to the latest TReK release. It uses the Command C++ API to provide its functions. For new code consider using the Command C++ API as it provides more features than the Command ANSI-C API. A few functions from the Release 3.x API are not currently supported. Information is provided about these functions further down this page.

Sending Commands
There are six functions provided to send commands. The availability of any of the functions is dependent on the destination. All of the functions will fail safely if not available for a destination.

UplinkUserCommand() - Sends the binary command passed as a function parameter.
UplinkUserCommandVB() - Sends the binary command passed as a function parameter (intended for languages that don't support unsigned integers).
BuildAndUplinkCommand() - Sends a command that is defined locally to the destination. The local command can be updated prior to sending as needed.
AddHeaderAndUplinkCommand() - Inserts command data passed as a function parameter into a predefined command structure and sends the command to the destination.
AddHeaderAndUplinkCommandVB() - Inserts command data passed as a function parameter into a predefined command structure and sends the command to the destination (intended for languages that don't support unsigned integers).
UplinkPOICCommand() - Sends a request to the destination to initiate a command uplink for the specified command.

Updating Commands
Any command that is added from the GUI can be updated through the Command ANSI-C API.

GetNumericFieldValue() - Get the current value of a field that is a numeric data type.
GetStringFieldValue() - Get the current value of a field that is a string data type.
GetBinaryFieldValue() - Get the current value of a field that is a binary data type.
UpdateNumericFieldValue() - Update a field that is a numeric data type.
UpdateStringFieldValue() - Update a field that is a string data type.
UpdateBinaryFieldValue() - Update a field that is a binary data type.
UpdateBinaryFieldValueVB() - Update a field that is a binary data type (intended for languages that don't support unsigned integers).
UpdatePOICDatabase() - Update the contents of a command in the POIC database with the contents of the local command.

Destination Specifics
For a POIC destination you can obtain status and configuration information through the Command ANSI-C API.

GetPOICCommandSystemConfiguration() - Contains information on the POIC command system configuration including the clear to send mechanism.
GetPOICCommandSystemStatus() - Contains information on the POIC command system status including user enablement.
SetNumberOfRetries() - Resets the number of attempts for sending a command from the POIC to MCC-H.

Currently Unsupported Functions.
These functions all required the Remote Services application available in Release 3. Current security requirements make a new application more difficult to support and these are not planned for future development. If you use these functions and need to continue using them in the future, please contact the TReK help desk.

UplinkTReKCommand()
UpdateDestinationDatabase()
GetValidationEventName()
ChangeUplinkPacket()
GetUplinkPacketForValidation()
SendValidationResults()

Examples
The following examples are provided to show how to use Command APIs:

Command ANSI-C API Example
Uses the Release 3 Compatible API to check on user status, update, and uplink a command.
Source File:
cmd_api_r3/cmd_api_r3_main.c

Additional Dependencies
The TReK Command ANSI-C API (trek_cmd_user_api) is also dependent on the following libraries. See the Libraries main help page for more information.

trek_command_api
trek_toolkit_common_api
trek_toolkit_data_api
trek_toolkit_utilities_api
xerces-c_3_1