The CFH File Extension

Fieldbus

• Fieldbus Foundation is both the name of the networking standard and the organization that defined it. A general distinction between the two is made by capitalizing all the letters in the name of the standard. The organization is an industry group of about 350 companies. The members of the organization are all either producers or major users of industrial networking applications. Fieldbus Foundation was formed by the merger of InterOperable Systems Project (ISP) and WorldFIP North America in 1994. It is a not-for-profit organization. The Fieldbus Foundation is not a standards body. It defines standards and then strives to get them validated by international standards bodies.
  
  

Types of Network

• Fieldbus FOUNDATION supports two different physical layers of the network. The lower speed network is called H1 and was first defined in 1995, with the first compatible components appearing in 1998. Fieldbus FOUNDATION H1 employs capability files with the CFF file extension. The Industrial Ethernet-based system achieves data transfer rates of up to 100 Megabits per second, which is more than three times the speed of H1. This faster networking system is Fieldbus FOUNDATION HSE (High Speed Ethernet). The Foundation began work on the definition of HSE in 1999. This standard was complete in 2001. Its capability files use a CFH file extension.
  
  

Network Nodes

• The Fieldbus FOUNDATION HSE network connects together actuators, sensors and Programmable Logic Controllers (PLCs). PLCs control industrial machinery like lathes and welders. Each node on the network needs to have a capabilities file. This file explains the networking capabilities of the device. Usually, the equipment will be shipped from the manufacturer with a capabilities file in its supporting documentation.
  
  

Capabilities File

• The capabilities file is written in plain text. It is like a configuration file except its information is intended not for the associated equipment, but for access by a central network controller. The file is formatted in paragraphs. Each paragraph is headed by a category in square brackets. Each line in each paragraph is listed as a parameter and a value. The parameter name is taken from Fieldbus standards. It is mixed case and contains no spaces. An example of a line in the file is "NumberOfSoftwareDownloadObjects=1."