Standards update: Modbus becomes Chinese standard; PC/104 Consortium to adopt EPIC spec
Ubiquitous Modbus network protocol has enjoyed wide de facto application in China.
Ubiquitous Modbus network protocol has enjoyed wide de facto application in China. Recently it has gained official status in that country, being adopted as a standard in the People’s Republic of China (PRC). Meanwhile, the PC/104 Embedded Consortium agreed to adopt the new EPIC Specification to widen support of embedded platforms that embrace PC/104 technology. More details about each development follow.
The Standardization Administration of China (SAC) has formally launched three standards for industrial automation in the PRC—as announced by Modbus-IDA , the international organization for suppliers, implementers, and users of Modbus and its companion protocols. The new Chinese standards comprise three parts of “Modbus Industrial Automation Network Specification,” namely:
GB/Z 19582.1-2004 (Part 1) Modbus Application Protocol;
GB/Z 19582.2-2004 (Part 2) Modbus Protocol Implementation Guide over Serial Link; and
GB/Z 19582.3-2004 (Part 3) Modbus Protocol Implementation Guide over TCP/IP.
Mr. Ouyang Jinsong, director of standardization, Department of Instrumentation Technology & Economy Institute, PRC and general secretary of the National Standardization Technical Committee on Industrial Process Measurement and Control, confirmed the standards were effective Oct. 26, 2004.
Modbus-IDA welcomed the news, calling it “a striking affirmation of the ubiquitous Modbus protocol.” Chinese standardization authorities have been working closely with Schneider Electric as they develop and propagate use of standards in their industrial infrastructure. Along with launching the Modbus standard, a conformance test laboratory is anticipated to open in China within the next few months, according to Modbus-IDA.
Ken Crater, president of Modbus-IDA, says, “It makes sense that the Chinese industrial market adopt Modbus as its fieldbus standard. Simplicity and ease of integration make it a natural choice. The fact that it is already widely used in China was also an important factor in the standardization decision.”
Form factor of EPIC specification measures 29.4 sq in., which is virtually the midpoint footprint size between EBX and PC/104 formats for single-board computers.
With an overwhelming majority of member votes, the PC/104 Embedded Consortium recently announced its adoption and management of the new EPIC standard for mid-sized (4.5 x 6.5-in.) embedded single-board computers (SBCs). The move widens the Consortium’s support of embedded platforms that embrace PC/104 technology. EPIC’s format supports PC/104 and PC/104- Plus as part of its specification.
EPIC—Embedded Platform for Industrial Computing—represents the next generation of mid-sized SBCs, says the PC/104 Consortium. “EPIC standard represents an excellent opportunity for manufacturers to provide PC/104 technology to users in an efficient footprint and in combination with some of the latest CPU technology in the industry.” In a parallel path in 2004, the PC/104 Consortium adopted the EBX standard—which is used for implementing PC/104 technology on a larger footprint (see graphic).
EPIC standard was developed through cooperative technical effort of several companies: Ampro Computers Inc. , Micro/Sys , Octagon Systems , VersaLogic , and WinSystems . Products are available from these companies. EPIC specification is in review and accessible to users at the Consortium’s Web site.
—Frank J. Bartos, executive editor, Control Engineering, email@example.com