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Command: Online Config Mode

Function: The command is for switching the online configuration mode on and off. When switching on, it establishes a connection to the PLC and downloads an implicitly created HiddenOnlineConfigModeApp application to the PLC. Depending on the device, CODESYS goes into simple online configuration mode or a dialog opens for selecting between simple and advanced online configuration mode.

Call: Context menu of the PLC object in the device tree

Requirement: The communication settings for the PLC device are set correctly.

Simple online configuration mode

The command creates the implicit HiddenOnlineConfigModeApp application and downloads it to the controller. The application automatically initializes all inputs and outputs of the controller one time. After that you can access the I/Os as follows:

  • Read I/Os

  • Write outputs

  • Diagnosis (in the device tree and on the Status tab of the device editor)

  • Scan (of the current hardware)

  • Interactive online functions, if available (for example, writing asynchronous messages)

Advanced online configuration mode (parameter mode)

If there are already applications on the PLC and the controller supports it, the command first opens the Devices dialog, which displays the applications existing on the controller. In this dialog, you can click the Parameter Mode button to connect to the PLC and then access the values of the device parameters without having to log in with a real application.

Writing and forcing in the I/O mapping

In online configuration mode, the writing and forcing of values on the I/O Mapping tab works differently as in real online mode. The outputs are written immediately after insertion into the table. There is no Prepared Value column, but the initial values can be changed directly after you double-click the Current Value column.

Dialog: Select config mode

The dialog opens after the Online Configuration Mode command if the device supports the advanced online configuration mode and there are already real applications on the controller.

Parameter mode

The controller configuration in the project is compared with that on the device. If they correspond, then CODESYS establishes a connection to the PLC. Unlike the simple online configuration mode, it allows for reading and – if supported by the driver – writing of parameters in the generic device editor. The applications already downloaded to the device remain unchanged in this case.

Config mode

CODESYS switches to "Simple online configuration mode".

For more information, see: Checking the controller configuration with the help of the Online Config Mode command

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