Interaction with the graphical user interface (GUI)

The Frame tool

The Frame tool is used to generate a new TxFrame element within an EAP device object. Frame elements can only be generated within the box of an EAP device object that is located within the Publisher Area or the Configuration Area.

The TxData tool

Within a TxFrame, TxData elements are then added with the aid of the TxData tool . TxData elements cannot be generated anywhere else.

In addition to the standard commands, the context menu for the TxData element contains the command [Process Data Configuration]. The command opens a dialog for generating and editing TxPDO elements. One of the TxPDOs can then be selected for the TxData. A more detailed description of the dialog can be found in section Generating a communication link manually.

The RxData tool

The RxData tool is used to generate a new RxData element within an EAP device object. RxData elements can only be generated within the box of an EAP device object that is located within the Subscriber Area or the Configuration Area.

Like for TxData elements, in addition to the standard commands, the context menu for the RxData element contains the command [Process Data Configuration], which can be used to generate and edit RxPDO elements, and to assign them to the RxData (cf. section Generating a communication link manually).

The Connector tool

The Connector tool is a wizard, used for semi-automatic configuration of a communication link between two EAP device objects. Two application cases are supported: TxData to RxData and EAP device object to EAP device object.

TxData to RxData
The first case relates to the application of a Connector between TxData and RxData. For this action the properties of the respective Publisher and Subscriber elements are adjusted such that a communication link is created.

It lists three options which can be set as required, and depending on the current configuration status:

• Set Frame Target Address from Target EAP Device.
  This option is enabled by default. In this case, the AMS NetID of the target EAP device is entered as destination address during automatic generation of the TxFrame.
• Set ID and Version from TxData.
  This option ensures that the identification number and the version number of the selected TxData element are adopted during configuration of the RxData Subscriber element. If these two properties do not match, a communication link cannot be established.
• Generate Process Variables corresponding to TxData PDO.
  This option is only available if a TxPDO has already been defined and configured on the Publisher side for the TxData. Ideally, the TxPDO should already have the full list of references for the required Tx variables. This ensures that the whole RxPDO including all required Rx variables is created and configured on the receiving side. Accordingly, the communication link is then also configured correctly.

EAP device object to EAP device object
The second case is the use of a Connector between two EAP device objects. With this action, a Publisher with all the nested elements it requires is created and preconfigured for the EAP device object with the starting point of the Connector. For the EAP device object with the end point of the Connector, a Subscriber with all the nested elements it requires is created and preconfigured according to the previously created Publisher, so that a valid communication link is available.

The dialog is divided into two halves. In the left half, a list box shows all symbol names of process variables whose data can be sent with the aid of the EAP device. The process variables may originate from a PLC program of the machine on which the EAP device was instantiated, for example.

In the right half, the symbol names of the process variables of the target machine are listed, to which the target EAP device can write the received data. If no symbol names are listed, no communication link can be generated.

The dialog offers several filter options for the symbol table. One option is to display all available symbol names: either symbols that have already been used, together with unused symbols (Used and Unused); or only symbols that have not yet been used (Unused).
In addition, you can select whether only the symbols for the input variables should be listed (Exclude Output enabled) or only the symbols for the output variables (Exclude Input enabled) or both (neither Exclude Input nor Exclude Output enabled). By default only the symbols for the output variables are shown on the left (for the EAP Publisher) and only the symbols for the input variables on the right (for the EAP Subscriber).

If a symbol from one of the two lists has been selected, the two filter options Matching Size and Matching Type can be used in a meaningful way. If, for example, the symbol for a process variable was selected on the left for the EAP Publisher, the symbol name list for the EAP Subscriber on the right can be filtered such that only the symbol names of the process variables are listed,

• with a Matching Size
  (the data type has the same size as the data type of the Publisher process variable);
• with a Matching Type
  (the data type is the same as the data type of the Publisher process variable);
• or with a Matching Size and a Matching Type
  (both properties match).

Finally, there is the option Set Frame Target address from Target EAP Device. This option is enabled by default. In this case, the AMS NetID of the target EAP device is entered as destination address during automatic generation of the TxFrame.

Generating a communication link manually

The ideal approach to generating a communication link between two EAP device objects manually is to generate and configure the variables and process data objects (PDOs) first (See sections Generating variables and Generating process data objects). A Tx/Rx PDO then represents a data unit, for which send and receive characteristics can be configured with the aid of a TxData and TxFrame or an RxData element. Once the required PDOs have been created, the required TxFrames, TxData and RxData can be created (cf. sections The Frame tool, The TxData tool and The RxData tool) and fully configured (cf. sections The Frame, The TxData and The RxData).

Reading an active device configuration

The command [Read from Device] from the context menu of the EAP device object reads the current device configuration of a TwinCAT EAP device. Three conditions must be met:

• The TwinCAT EAP device must be active.
• An ADS/AMS route must be entered from the PC on which the TwinCAT EAP Configurator runs to the PC on which the TwinCAT EAP device runs.
• The Local AoE Net ID must be entered correctly in the TwinCAT EAP Configurator under the EAP device properties.

An TwinCAT EAP device only becomes active once it was configured and activated via TwinCAT 3. If one of these prerequisites is not met, the TwinCAT EAP Configurator cannot communicate with the EAP device. Once the current EAP configuration has been read, it is visualized directly.

The current device configuration is discarded. When a device configuration is read, the existing configuration is discarded and is therefore lost, if it was not backed up.

Writing a new device configuration

One of the main functions provided by the TwinCAT EAP Configurator is writing of a device configuration. The convenient option to generate and modify an EAP configuration with the aid of the TwinCAT EAP Configurator leads to the need to transfer this configuration to a TwinCAT EAP device. In addition to the prerequisites for reading an EAP configuration, a further requirement must be satisfied for reading.

Before a configuration can be transferred to a TwinCAT EAP device, the device must be set to a suitable state, in which changing the configuration is uncritical. The TwinCAT EAP device features a state machine with four states.

• Init (INIT)
  The TwinCAT EAP device is never in INIT state, except for a short time during activation of the TwinCAT project. In this case the EAP device was already instantiated, but not yet configured.
• Pre-Operational (PREOP)
  In PREOP state the TwinCAT EAP device is fully preconfigured, so that cyclic processing of the process data is ready to commence. In PREOP state further configurations can be implemented in the TwinCAT EAP device, e.g. with the aid of the TwinCAT EAP Configurator.
• Safe-Operational (SAFEOP)
  When the EAP device switches from PREOP state to SAFEOP state, the current configuration is checked for consistency, references between objects defined via the configuration are created, and links to the PLC variables are created based on the configured symbol names. In SAFEOP state the EAP device already sends variables, but it does not yet receive data.
• Operational (OP)
  In OP state, the EAP device receives and sends the configured process data cyclically and highly deterministically.

Before the new device configuration can be written, the TwinCAT EAP device must be switched to PREOP state. The state can be switched using the icon bar in the EAP Config Tool Window (see section Displaying the object dictionary).

A device configuration can be written in two ways:

• Write All to Device
  The command [Write All to Device] transfers all configuration data relating to the EAP device object in the TwinCAT EAP Configurator to the TwinCAT EAP device. All these configuration data are grouped with the aid of the object dictionary (cf. section The object dictionary). The command [Write All to Device] can also be called up from the icon bar .
• Write Changes to Device
  The command [Write Changes to Device] it used to selectively transfer those configuration data to the TwinCAT EAP device, which were modified with the aid of the TwinCAT EAP Configurator. The modifications are indicated with a yellow marker, which is displayed in the object dictionary and in the graphical interface. The object dictionary contains detailed information on which entries were modified. The command [Write Changes to Device] can also be called up from the icon bar .

Once the transfer is complete, the marking for the successfully written configuration data changes to green. Any configuration data for which the transfer failed are marked in red.

Displaying the object dictionary

All configuration data relating to the EAP device object in the TwinCAT EAP Configurator are grouped with the aid of the object dictionary. This object dictionary can be displayed in tabular form by selecting the command [Show in Tool window] from the context menu of the EAP device object (see illustration). Up to four of these Tool windows are supported, so that the object dictionaries of up to four different EAP devices can be viewed at the same time.

At the top of the Config Tool window, the file name of the corresponding EAP device object is displayed, and an icon bar below, which can be used to execute several commands (see illustration above), as explained below.

Set EAP Device State

The first four icons can be used to change the state of the TwinCAT EAP device. Each of the four states of the EAP state machine has an icon.

Read from Device

The icon executes the command [Read from Device] as described in section Reading an active device configuration.

Write Changes to Device

The icon executes the command [Write Changes to Device], as described in section Writing a new device configuration.

Write All to Device

The icon executes the command [Write All to Device], as described in section Writing a new device configuration.

Clear Object Dictionary

The icon executes the command [Clear Object Dictionary], as described in section Deleting the configuration.

Clear Change Flags

The icon executes the command [Clear Change Flags], as described in section Configuration state display.

Compare to Online Data

The icon can be used to add a further column to the object dictionary, in which the configuration data of the currently active TwinCAT EAP device are displayed. The icon works like a toggle switch, i.e. the column appears when the icon is clicked for the first time and is hidden when it is clicked again. Whenever the column display is enabled, the configuration data are read from the TwinCAT EAP device again and displayed.

Deleting the configuration

The configuration can be deleted via the command [Clear Object Dictionary] from the context menu of the EAP device object. A configuration can be deleted separately for each EAP device object. All objects (except a few) are deleted from the object dictionary of the respective EAP device object, so that the configuration is empty. The objects that are not deleted are standard objects, which are part of every EAP device and therefore cannot be deleted. They include the status of the EAP devices and the destination address such as MAC, IP and AMS NetID. This information is required by the TwinCAT EAP Configurator, for example, in order to be able to communicate properly with the TwinCAT EAP device.
The objects that can be deleted are the dynamic objects generated while new elements such as TxFrame, Tx/Rx data, Tx/Rx PDOs or Tx/Rx variables are created.

Configuration state display

The TwinCAT EAP Configurator executes various tasks on the configuration data of the EAP device objects. Some of these tasks are indicated in the graphical interface and in the tabular display of the object dictionary through colored flags. This flag indicates the configuration state and has the following meaning:

The flag can be reset with the command [Clear Change Flags] from the context menu of the EAP device.