Tab ‘PLC settings’

On this tab of the generic device editor you make the basic settings for the configuration of the PLC, for example the handling of inputs and outputs and the bus cycle task.

Application for I/O handling Application that is responsible for the I/O handling.
PLC settings
Update IO while in stop

024bd3d3dd3468d6c0a8640e01ba6ec0_9a3f06830c0506c5c0a8640e012f0ace : CODESYS refreshes the values of the input and output channels even if the PLC is in the stop state. If the watchdog detects a malfunction, the outputs are set to the predefined default values.

024bd3d3dd3468d6c0a8640e01ba6ec0_4681610f0c058035c0a8640e0049916a : CODESYS does not refresh the values of the input and output channels when the PLC is in the stop state.
Behaviour for outputs in Stop

Handling of the output channels when the controller enters the stop state:

  • Retain values: the current values are retained.
  • All outputs to default value: the default values resulting from the I/O mapping are assigned.
  • Execute program: you can control the handling of the output values via a program contained in the project, which CODESYS executes at “STOP”. Enter the name of the program in the field on the right.
Always update variables

Global setting that defines whether CODESYS updates the I/O variables in the bus cycle task. This setting is effective for I/O variables of the slaves and modules only if ‘deactivated’ is defined in their update settings.

  • Deactivated (update only if used in a task): CODESYS updates the I/O variables only if they are used in a task.
  • Activated 1 (use bus cycle task, if not used in a task): CODESYS updates the I/O variables in the bus cycle task if they are not used in any other task.
  • Activated 2 (always in bus cycle task): CODESYS updates all variables in each cycle of the bus cycle task, regardless of whether they are used and whether they are mapped to an input or output channel.
Edit Licenses This command opens the dialog box Edit licenses for the management of your device licenses.
Bus cycle options
Bus cycle task

Task that controls the bus cycle. By default the task defined by the device description is entered.

By default the bus cycle setting of the superordinate bus device (use cycle settings of the superordinate bus) applies, i.e. the device tree is scanned upwards for the next valid bus cycle task definition.

Pay strict attention to the following notes!

Attention

Before you select the setting <unspecified> for the bus cycle task, you should be aware of the following: ‘<unspecified>’ means that the default setting given in the device description becomes effective. You should therefore check this description. Use of the task with the shortest cycle time may be defined as the default there, but use of the task with the longest cycle time could equally well be defined!

Attention

For fieldbuses, a fixed cycle matrix is necessary to assure a determined behavior. Therefore, do not use the type ‘free-running’ for a bus cycle task.

Additional settings
Generate force variables for I/O mapping

This setting is available only if it is supported by the device.

024bd3d3dd3468d6c0a8640e01ba6ec0_9a3f06830c0506c5c0a8640e012f0ace : When compiling the application CODESYS creates two global variables for each I/O channel that is mapped to a variable in the dialog box I/O Mapping. You can use these variables for the forcing of the input or output value on this channel, for example via an HMI visualization.
Enable Diagnosis for devices

024bd3d3dd3468d6c0a8640e01ba6ec0_9a3f06830c0506c5c0a8640e012f0ace : CODESYS automatically integrates the library CAA Device Diagnosis in the project and creates an implicit function block for each device. If there is already a function block for the device, then either an extended FB is used (for example with EtherCAT) or a further FB instance is added. This then contains a general implementation for the device diagnosis.

By means of the FB instances you can determine the status of all devices in the application and evaluate errors. In addition, the library contains functions for the programmatic editing of the device tree. Example: scanning of all children of a bus system, jumping to the parent element.
Show I/O warnings as errors Warnings concerning the I/O configuration are displayed as errors.

See also