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 601: PLC Settings
“Refresh I/Os in stop”	: 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 “Disabled” is defined in their update settings. “Disabled (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.

Table 602: 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.

NOTICE

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!

NOTICE

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 603: 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.
“Enable online configuration change”	This option is available only when the device description includes the setting for the online change feature. : If the device configuration of the project has changed, or if new devices have been added which have the setting for the online change feature in their device description, then an online change is possible without restarting the application. The existing devices continue to run without interruption, and the new devices are initialized and set to operating mode. The same applies when a device is deleted. When this option is enabled, logging in without download is no longer possible. When this option is enabled, direct addresses are no longer possible for devices with I/O channels. For more information, see: .