The configuration data of the PLC controllers of bus systems can be exchanged with different PLC configuration programs. The PLC configuration data exchange is based on an exchange file that one editing program writes and another editing program reads. This file can be exchanged simply between the EPLAN designer and the PLC programmer.

PLC configuration programs and EPLAN view the configuration data differently. While the electrotechnical hardware details are represented in EPLAN, PLC configuration programs have a logical view for the purpose of the PLC programming. For instance, there are PLC connection points in EPLAN that are dedicated to the power supply. These connection points are not required in the PLC configuration program. On the other hand, there is interface information, such as router information, in the PLC configuration programs that is not needed in EPLAN. Data that an editing program does not find in the exchange file because the other editing program does not know them, are supplemented during importing.

EPLAN treats the Ethernet-based bus systems equivalently during exporting / importing, because they have the same hardware topology.

Scope of interface

In principle the following configuration data is exchanged:

• Hardware data of the used devices
  Rack structure with part information.
• Symbol table (also called assignment list, table of variables or similar)
  Assignment of the symbolic address to a hardware address.
• Network structures
  Logical view (association of the devices to networks), not the exact cabling.

Through the different views of the programs and the current developments on the hardware and software sector, the data exchange cannot always cover all the requirements. The applies for example to passive items in the bus bundle and used field bus systems.

Device identification

Identification of the devices both in EPLAN and in the PLC configuration program is effected either by means of the PLC type designation or by specifying a device description file. The part allocation during the import of PLC configuration files is also carried out on the basis of these properties.

Every PLC card can only have one device identification. A combination of several parts by entering several PLC type designations, device description files or indexes is not supported.

PLC type designation

The PLC type designation often corresponds to the order number in the hardware catalog of the respective PLC configuration program. The upper- / lower-case letters as well as the position of blanks has to be taken into consideration. For certain Import formats several parts with the same PLC type designation can be differentiated by means of the Object description property.

Device description file

The specification of a device description file can be necessary, among other things, if you use devices from different manufacturers within a bus system, for example a Beckhoff device that is coupled with a SIEMENS control unit.
A device description file contains device information that is not contained in the default hardware catalog of a manufacturer. You obtain device description files (for example GSD files) from the manufacturers of the used components. These files have to be integrated into the default hardware catalog of the PLC configuration program.

A description file is specified at the PLC card in the Device description: File name property. The file name is entered with the file name extension, but without file path. In addition to the Device description: File name property, the Object description property or - when exchanging data in the AutomationML format - the Device description: Index in file property has to be specified as well. On the basis of these properties a device is selected within the file during the import of PLC configuration files.

In the Device description: File name property not only the GSD file name but also other entries, for example device IDs of CC-Link modules, can be stored. To this purpose you enter a prefix followed by a colon before the actual device ID, for example CSP+:AJ65VBTCE2-8T. This entry is then exported unchanged. This value also has to be contained in the parts management for the import. Otherwise the device cannot be found during importing.

If the entry does not contain a prefix (meaning no colon) or the prefix "GSD:", for example GSD:SIEM8139.GSD, the entry is interpreted as a device description file. In this case the device description file name is exported together with the index (if it exists).

Recommendations for the project planning

Begin with the rack layout on a single-line schematic page. Use single-line PLC boxes as main functions.

• The hardware data of the used devices is planned through the rack layout. All the main functions exist in the single-line representation. When this representation is copied, the parts entered there are copied as well.
• Individual functions (I/O connection points, power supply, bus ports, etc.) can be placed via drag & drop from the PLC navigator.
• The rack layout can be exchanged with PLC configuration programs.

Connect the single-line bus ports of the modules via autoconnecting.

• The network structure can be documented clearly by connecting the single-line bus ports.
• The network structure can be exchanged with PLC configuration programs.

Place the I/O connection points with the associated sensors / actuators on multi-line schematic pages. Use bitwise representation (meaning one macro per channel) with functional grouping of the devices. Represent one I/O connection point with the associated sensor / actuator and, if applicable, main circuit per page.

• Once macros have been created they can be used repeatedly for similar machine functions.
• I/O connection points or channels can be placed via drag & drop from the PLC navigator or assigned.
• You can check the assignment in the PLC navigator or on an overview page.

See also

Structure of PLCs

Exporting PLC Configuration Files

Importing PLC Configuration Files