Terms Used

The configuration interface in e!COCKPIT, as well as this documentation, uses certain technical terms from the CIP or EtherNet/IP specification:

Scanner/Adapter

The EtherNet/IP standard uses the terms “scanner” and “adapter.”
Note: Please note that the configuration interfaces in e!COCKPIT and this document generally speak of the “master” (scanner) and “slave” (adapter) due to their use for different fieldbuses.

In EtherNet/IP, I/O data (input and output data points) is transferred via so-called connections (“implicit messaging”). When the fieldbus starts up, one or more connections can be established between an EtherNet/IP master and an EtherNet/IP slave. The input and output data points of a connection and the configuration data is grouped into so-called assemblies. To see which connections a slave device support, consult the device description file (EDS file) or the respective product manual of the slave.

The connections and the data to be transferred are usually configured automatically using the information contained in the EDS file, and the configuration can be viewed or changed in the data point configurator. The connections to be transmitted can then be selected in the fieldbus configurator, and the communication parameters can be adjusted, e.g., the cycle time for data transmission (RPI).

Explicit messages are used when establishing a connection between master and slave and for writing user parameters, for example. They are also used by the IEC library “EtherNet/IP Services,” via which services for communication with slave devices can be implemented in the program of the EtherNet/IP master (see “EtherNet/IP Services” IEC Library). This enables the exchange of certain data via the fieldbus (e.g., status queries).

User parameters can be defined in an EDS file. These can be general settings for the device. The parameters are written by “explicit messaging” to the slave device by the master before the connections are established. If parameters cannot be written to the slave device, communication is cancelled, in which case no connections are established. User parameters are configured on the “User Parameters” Tab of the data point configurator.

This notation is used to indicate the direction of communication.
T (Target) represents the slave and O (Originator) the master. This entails the following meanings:

• T → O: The slave sends data to the master (input data)
• O → T: The slave receives data from the master (output data)

When connections are established, the data is exchanged between master and slave via assembly instances. Each assembly instance in the slave device has a specific data structure, which is defined in the EDS file of the slave or in the respective product manual. The assembly instances of a connection are classified as follows:

• Input Assembly
  The assembly defines the input data points of a connection that are transferred from the slave to the master (T → O).
• Output Assembly
  The assembly defines the output data points of a connection that are transferred from the master to the slave (O → T).
• Configuration Assembly
  The assembly defines configuration data that is transferred from the master to the slave when a connection is established. Two configuration assemblies can be defined for a connection:
  • Target configuration
  • Proxy configuration^*

Via the assemblies input data points, output data points and configuration data can be combined into a data block to allow efficient access to the data for communication on the fieldbus.

With non-modular slave devices, the structure of an assembly is typically fixed. With modular slave devices, the input and output data points must be set in the data point configurator or result from the node configuration (e.g., with WAGO fieldbus couplers). Examples of modular slave devices include fieldbus couplers, which have a different number of input/output data points depending on the hardware configuration.

^* Note: WAGO’s EtherNet/IP solution does not currently support proxy configuration. An EDS file that contains a connection with an assembly for the proxy configuration is imported, but the connection is not displayed in the data point configurator or offered for selection when a connection is created. In the data point configurator, configuration data of a connection’s target configuration is only displayed if this configuration is defined for the connection in the EDS file.

There are different types of connections, defined via the application type. The following types are supported:

• “Exclusive Owner” Connection
  An “exclusive owner” connection is not dependent on another connection for its existence. The target (slave) accepts only one “exclusive owner” connection per path. Both input and output data can be exchanged via “exclusive owner” connections.
• “Input Only” Connection
  An “input only” connection is not dependent on another connection for its existence. A target (slave) can accept multiple “input only” connections that have the same path. Only input data is exchanged via “input only” connections (slave sends to master).
• “Listen Only” Connection
  A “listen only” connection depends on a pre-existing “exclusive owner” or “input only” connection; otherwise, it cannot be established. A target (slave) can accept multiple “listen only” connections that have the same path. If the last connection on which a “listen only” connection depends is closed or times out, no more data is sent via the “listen only” connection. Only input data is exchanged via “listen only” connections (slave sends to master).
• “Redundant Owner” Connection
  A “redundant owner” connection corresponds to an “exclusive owner” connection, with the difference that multiple senders/masters can try to claim the connection for themselves. All masters configured as “redundant owners” receive messages from the slave. However, the slave only uses the messages of the one connection. If this connection drops out, another master configured as a “redundant owner” can take over the communication. The current owner of a connection is determined by certain values in the header of the O → T message.
  Note: In WAGO’s current EtherNet/IP solution, connections can only be established between one slave and one master, not multiple masters.

The path of a connection specifies the addresses of the assembly instances that are transferred by a connection (input, output and configuration). The path of a connection can be fixed or parameterizable. If it is parameterizable, different assembly instances can be configured, and thus different data can be made available via the assembly.

Note: The input and output data points must match the assembly instances set in the path. If this data is defined via the EDS file, it is displayed in the data point configurator. If the data is not defined in the EDS file (e.g., for modular devices), the data must be adjusted to the new assembly instance according to the definitions in the product manual of the device when an assembly instance is changed in the path. For WAGO fieldbus couplers, this adjustment is made automatically based on the node configuration.

The input, output and configuration sizes represent parameters of a connection and specify the size of the assembly data structure in bytes for the three possible assembly instances. The sizes are defined for each connection by the EDS file or are specified in the product manual of the device. They can be fixed or parameterizable.

• Configuration Size (Target)
  The size of the configuration assembly is usually fixed and should not be changed. However, the manufacturer may provide for a configurable size. In this case, configuration options must be checked in the product manual of the device.
• Input Size (T → O), Output Size (O → T)
  The sizes for the input and output assemblies are defined via the EDS file and are usually configurable. The limits on the input/output sizes are listed in EtherNet/IP Master: Features and Functions.

Two cases must be distinguished for setting input/output sizes:

• Non-Modular Devices
  For these devices, sizes are usually specified via the EDS file and do not have to be modified (example: WAGO I/O System Field, 0765-4503/0100-0000). However, the manufacturer may provide for configurable sizes. In this case, configuration options must be checked in the product manual of the device.
• Modular Devices (e.g., fieldbus couplers)
  For these devices, the sizes are not fixed and are therefore configurable. The sizes result from the device configuration (input/output modules in the case of a fieldbus coupler). The input and output data points of the assemblies are configured in the data point configurator. This yields the byte sizes that must be set (see the example of setting the input and output data points in Example Configuration for Data Exchange with a WAGO EtherNet/IP Fieldbus Coupler 750-363).

The “Electronic Data Sheet,” or EDS file for short, is a device description file in ASCII format that specifies how a device can be used in an EtherNet/IP network. It is provided by the device manufacturer and contains the descriptions of all relevant communication parameters and data of the EtherNet/IP device. Furthermore, it provides information that a configuration tool can use to identify the device.
In e!COCKPIT, the EDS file of a device can be imported (Backstage View > “Product Catalog” page). This adds the device to the e!COCKPIT product catalog and allows it to be integrated into a network and configured according to the information in the EDS file. Notes on the “Electronic Data Sheet” (EDS) Device Description File describes which information of an EDS file the WAGO EtherNet/IP solution supports.

A “Generic_EtherNet/IP_Adapter” is available in the e!COCKPIT product catalog. This can be used if no EDS file is available for a device. The necessary configuration data for the device can then be entered on the basis of the product manual of the device.