Commands and Signals (I/O Camera)

MERLIC provides various signals and commands when using a camera device with digital I/O channels for the process integration mode of MERLIC. The commands can be used by the PLC to trigger different events, for example, the execution of the MERLIC Vision App (MVApp).

To ensure a correct configuration of the input and output channels, the information about the available signals and commands should also be considered. The assignment of the input and output channels to the respective commands and signals is crucial for the correct usage of MERLIC in process integration mode. For more information on the configuration, see Configuring I/O Cameras.

Overview of Supported Commands

Depending on the type of device or plug-in used for the process integration, different restrictions might apply. The following tables gives a short overview which commands are supported for the different types of plug-ins.

Device	Start continuous execution	Start single execution	Change recipe	Get MVApp results	Check MERLIC state	Get image results
Hilscher card	✔	✔	✔	✔	✔	✘
Digital I/O device	✘	✔	✔	✔ (Only Boolean values)	✔ (Only "Ready" and "Error")	✘
Camera with GenICam compliant digital I/O channels	✘	✔	✘	✔ (Only Boolean values)	✔ (Only "Ready" and "Error")	✘
Communication plug-ins	✔	✔	✔	✔	✔	(✔)

When using cameras with I/O channels for the process integration, only single executions can be triggered. It is not possible to trigger a continuous execution of the MVApp. In addition, it is not possible to trigger a recipe change with the I/O camera. However, MERLIC will be aware if a continuous execution or a recipe change is triggered by another process to avoid conflicts.

Commands for I/O Cameras

For camera devices with digital I/O channels, MERLIC provides a command to trigger a single execution of an MVApp. To start the execution, the corresponding command must be triggered via the associated digital input channel.

Command	Description
StartSingleJob	Set the respective digital input to 1 to start a single execution of MERLIC. If "StartSingleJob" is set to 1 permanently, MERLIC is executed subsequently until the last execution is finished.

Signals for I/O Cameras

When using a camera device with digital I/O channels, some signals are provided by default. For example, the signals "Error" and "Ready" are provided for each digital I/O device. In addition, depending on the device multiple digital outputs are available for the transmission of MVApp results.

The following table lists the available signals for the communication between MERLIC and the I/O camera. To enable the transmission of a specific signal, you have to assign a digital output channel to the signal in the "I/O" tab of the MERLIC RTE Setup.

Signal	Description	Setting
Ready	The value of this signal indicates if MERLIC is ready for the execution. If it is set to 1, a recipe has been loaded and MERLIC is ready for the execution. In addition, it is also possible to change the recipe via a different communication device. When triggering a single execution, the "Ready" signal is necessary for the synchronization of the commands.	Mandatory
Error	The value of this signal indicates if an error occurred. If the value 1 is returned, MERLIC is in the "Error" state and a restart of MERLIC is required. An error occurs in the following cases: A recipe file with an invalid recipe ID is loaded. The configuration of the I/O channels is wrong in the "I/O" tab of the MERLIC RTE Setup. The number of input values in the recipe does not match the number of MVApp parameters An MVApp parameter represents a basic or an additional parameter in a MERLIC Vision App which can be modified via a recipe file when using MERLIC process integration. You can define a tool parameter as an MVApp parameter in the MERLIC Creator. The panel "MVApp Parameters and Results" shows a list of all MVApp parameters that are currently defined. defined in the referenced MVApp.	Mandatory
Result0 ... Resultn	These digital output signals can be used to transmit an MVApp result to the camera device. For more information, see MVApp Results.	Optional
ResultState	The value of this signal indicates the state of the queried result data. If it is set to 1, the processing was carried out correctly and the queried results are up-to-date. If it is set to 0, the processing failed or was aborted. In this case, no results might be available or the existing result values might not be up-to-date, for example, the values might be outdated and from a previous execution. 0 (Undefined/Processing/Aborted/Failed): The processing failed or was aborted. 1 (Completed): The processing was carried out correctly.	Optional