PCF Fieldbus Overview

Introduction:

Selecting the correct fieldbus configuration file is key to enabling the installation of a PCF node on a cell controller fieldbus.  This page contains descriptions of the various fieldbus configuration files available for the PCF systems, and their optional data maps.  Conceptual descriptions of the EDS, GSD, and GSDML files are provided for further understanding.

DeviceNet and EtherNet/IP EDS Files:

The CIP family of fieldbuses requires an Electronic Data Sheet (EDS) to be provided to the end user for each system on which the GCA-CGM is offered.  CIP standards, and Graco policy are to place the EDS files on the company internet page for free download.

The EDS is a specially formatted ASCII (text) data file that provides information about a device configuration data's context, content, and format. The information in an EDS allows configuration tools to provide informative screens that guide a user through the steps necessary to configure a device.  An EDS provides all of the information necessary to access and alter the configurable parameters of the device or system. It also provides a definition of the produced and consumed data items (objects), defining data type, size, and purpose of the item.

The EDS must be formatted in a precise manner, with specific keywords, and data presentation.  A software package called the EZ-EDS - EDS File Editor is offered by the ODVA for the generation and validation of EDS files, but use of this package requires an in-depth understanding of the CIP family and DeviceNet and EtherNet/IP in specific.

PROFIBUS GSD Files:

PROFIBUS DP family of fieldbuses requires a Generic System Description (GSD) file to be provided to the end user for each system on which the GCA-CGM is offered.  PROFIBUS standards, and Graco policy is to place the GSD files on the company internet page for free download. 

The GSD is an ASCII (text) file that contains both general and device-specific specifications for communication.  Each of the entries describes a feature that is supported by the device.  Utilizing predefined keywords, a configuration tool may read the device identification, the adjustable parameters, and the types and size for the data elements (Modules).

The GSD file has a predefined file name that is based on the manufacturing company's identification.  Previously, all CGM GSD files were named GRCI0B8A.  This is comprised of Graco's name reference and the PNO Ident number of the GCA-CGM (0B8A), and was assigned during conformance testing at a PI facility.  Note that the format of the file name is a PROFIBUS requirement, and a file with an incorrectly formatted name may be rejected by the customer's fieldbus configuration tool.

As a result of further research, it was determined that the first four letters are optional for selection by the module manufacturer.  So, as a change to the Graco policy, two initials representing the target system will be defined, and used in the creation of the filename. An example of the new file naming convention is: GRPF0B8A, to represent a Graco PCF system data map.
     
The GSD must be formatted in a precise manner, with specific keywords, and data presentation.  A software package called the GSD-Editor Version 5.0 is offered by PI for the generation and validation of GSD files, but use of this package requires an in-depth understanding of PROFIBUS communications to define a new GSD file.

PROFINET GSDML Files:

PROFINET fieldbuses require a Generic System Description file in an XML format (GSDML) to be provided to the end user for each system on which the GCA-CGM is offered.  PROFINET standards, and Graco policy are to place the GSDML files on the company internet page for free download. 

The GSDML is an XML(text) file that contains both general and device-specific specifications for communication.  Each of the entries describes a feature that is supported by the device.  Utilizing predefined keywords, a configuration tool may read the device identification, the adjustable parameters, and the types and size for the data elements (Modules).

The GSDML file has a predefined file name that is based on the version of the GSDML specification, manufacturing company's (Graco) name and generation date.  In addition, information may be inserted to make it specific to a system.  An example of a GSDML file generated for the Tandem Ram is: GSDML-V2.0-Graco-Tandem_Ram-20080925.xml.

The GSDML must be formatted in a precise manner, with specific keywords, data presentation, and XML formatting.  A software package called the PROFINET XML Viewer is offered by PI for the verification of GSDML files, but generation of the XML file requires an application such as XML Notepad 2007 from Microsoft Corporation, or some other text based editor.  The generation of a GSDML file requires an in-depth understanding of PROFINET communications and the XML format required.