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

Table 46. PLC Settings

Refresh I/Os in stop

standard icon : The values of the input and output channels are also refreshed when the PLC is in STOP mode. If the watchdog detects a malfunction, the outputs are set to the predefined default values.

: The values of the input and output channels in STOP mode are not refreshed.

Behavior of the outputs at stop

. Handling of the output channels when the controller enters STOP mode:

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: The handling of the output values is controlled by a program contained in the project which is executed in STOP mode. Enter the name of the program in the field on the right.

Always update variables

Globally defines whether or not the I/O variables are updated in the bus cycle task

This setting is effective for the 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): The I/O variables are updated only if they are used in a task.
Enabled 1 (use bus cycle task if not used in any task): The I/O variables in the bus cycle task are updated if they are not used in any other task.
Enabled 2 (always in bus cycle task): All variables in each cycle of the bus cycle task are updated, regardless of whether they are used and whether they are mapped to an input or output channel.
Important
The availability of this option depends on the device description.

Table 47. 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 applies (use cycle settings of the superordinate bus). This means that the device tree is searched upwards for the next valid definition of the bus cycle task.

Important

Before you select the "<unspecified>" setting for the bus cycle task, you should be aware that "<unspecified>" means that the default setting given in the device description goes into effects.

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!

Important

For fieldbuses, a fixed cycle matrix is necessary to assure a determined behavior. Therefore, do not use the "freewheeling" type for a bus cycle task.

Table 48. Additional Settings

Force variables for the I/O mapping	This setting is available only if it is supported by the device. : When compiling the application, two global variables are created for each I/O channel which is mapped to a variable in the I/O Mapping dialog. You can use these variables for the forcing of the input or output value on this channel, for example via an HMI visualization.
Activate diagnostics for devices	: The `CAA Device Diagnosis` library is integrated in the project. An implicit function block is generated for each device. If there is already a function block for the device, then either an extended function block is generated (example: EtherCAT) or another function block instance is added. This then contains a general implementation of the device diagnostics. By means of the function block 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. For more information, see: CAA Device Diagnosis Library Documentation
Display I/O warnings as errors	Warnings concerning the I/O configuration are displayed as errors.
Enable symbolic access for I/Os	: Input and output variables`(VAR_INPUT` and `VAR_OUTPUT`) are automatically created for the I/O channels of the device. For this purpose, an extended function block is created for each slave. The basis is the existing function block of the slave. This kind of automatically generated function block can be accessed directly in the application code. This symbolic access works in parallel to the I/O mapping which was set up manually. : Access to I/O channels is not supported. It is necessary to manually set up a mapping and specifically assign new or existing variables per I/O channel.