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Scanner Card Interface > Description > Operation Modes

Operation Modes
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The scanner card interface provides different operation modes for the underlying output device that influence command flow:

Continuous Mode:

In continuous mode the output device stays in a running state as long as execution is activated. In this mode the output device sees the incoming data as a continuous stream. It tries to execute a command sequence as soon as it is safe to do so or if it is forced to execute it by specific stream info commands. In this mode waiting for the end of a marking sequence should be done by calling the command. That function forces the execution of all available stream information, blocks the execution of the calling program and returns after marking has finished completely.

Non-Continuous Mode:

In the non-continuous mode the output device buffers commands and waits until it gets the execute command before it starts any marking operations. This mode requires each stream to be opened and closed with start and end markers explicitly. Additionally, control returns to the application and waiting for the end of the marking process can be done asynchronously. To do that the execute state can be checked. If its value becomes 0, marking has finished. If its value is set to 0 by the program explicitly, any ongoing marking process is canceled. The maximum allowed size of one stream depends on the implementation.

External Trigger:

If this mode is selected the output device waits until a trigger signal is detected before starting the marking process. The external trigger signal can be applied in continuous and non-continuous mode. This changes the behavior of continuous mode: flush no longer blocks execution, and the client application has to use other means to determine if its marking operation has finished (for example checking the exposure flag). The external trigger is set by a specific enable flag.

note

Set/GetContinuousMode

Flush

Stream Information

Set/GetExternalTrigger