# MTSCRA Functions To develop an iOS app using the MTSCRA SDK, follow the setup steps in section 2 How to Set Up the MTSCRA SDK, then create an instance of the MTSCRA object in your software project, then call the functions described in this chapter to communicate with the device. For sample code that demonstrates how to use these functions, see the contents of the MTSCRA Demo folder included with the SDK. Generally, these functions will run in one of two modes: * Asynchronous functions will return data using the event handlers (callback functions) defined in section 5 MTSCRA Delegate Methods. * Synchronous functions will return requested data immediately in the function’s return value. If the requested data is not available immediately, synchronous calls will generally block until a specified wait time has elapsed. Most calls that wait for input from the user will run in the asynchronous mode. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://developer.magtek.com/hardware/card-readers/magnetic-stripe-readers/idynamo-5-gen-iii/documentation/developers-manuals/secure-card-reader-authenticators-sdk-programmers-manual-ios/mtscra-functions.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.