# Using the function reference

This section provides an alphabetical reference to the NCC service functions. A prototype of each function is shown with the function description and details of all arguments and return values. A typical function description includes:

Prototype | The prototype is shown followed by a list of the function arguments. NMS Communications data types include: WORD (16-bit unsigned) DWORD (32-bit unsigned) INT16 (16-bit signed) INT32 (32-bit signed) BYTE (8-bit unsigned) If a function argument is a data structure, the complete data structure is defined.
Return values | The return value for a function is either SUCCESS or an error code. For asynchronous functions, a return value of SUCCESS indicates the function was initiated; subsequent events indicate the status of the operation. Refer to the Alphabetical error summary for a list of all errors returned by NCC service functions.
Events | If events are listed, the function is asynchronous and is complete when the DONE event is returned. If there are no events listed, the function is synchronous. Additional information such as reason codes and return values may be provided in the value field of the event. Refer to the event reference in this manual for details for all NCC service events.