There is one significant difference between the Scan Manager API and the PODSSymbolScanner API. The Scan Manager API requires you to open the Scan Manager library before you can make any other call to the library. PODSSymbolScanner opens the library for you whenever you enable a piece of the scanning hardware (that is, the aimer, the LED, or the scanner itself) and the library is closed.

Any time you disable the scanner, LED, or aimer, PODSSymbolScanner checks to see if any of the other scanning pieces are still enabled. If not, it closes the library for you. Closing the library when it is not in use prolongs battery life.

Calls that do not actually require use of the scanning hardware (such as the calls that retrieve version numbers) open the library, retrieve the requested information, and close the library when finished. The majority of PODSSymbolScanner calls, however, simply return NULL or -1 if the Scan Manager library is not open. If you want to explicitly control the opening and closing of the library, you can use PODSSetEnabled().