On the certification front: Enhanced DDL; flow monitoring, sensing

Efforts to expand the international standard on Device Description Language (IEC 61804-2) are being promoted by Emerson Process Management.

By Control Engineering Staff February 19, 2004

Efforts to expand the international standard on Device Description Language ( IEC 61804-2 ) are being promoted by Emerson Process Management . The company is collaborating with members of global standards groups to enhance DDL technology, which, according to Emerson, offers a better solution than the alternative Field Device Tool/Device Type Manager (FDT/DTM). The company says efficiency in ownership of process automation requires that users be able to cost-effectively add, upgrade, and integrate instruments, equipment, and systems of choice. Open, interoperable, standards-based DDL is proven global technology that meets these needs.

DDL provides underlying technology for use by host suppliers to design robust human-machine interface (HMI) and automation interfaces, and enhancements being developed will add to this functionality, says the company. DDL-based field devices from all suppliers will interface identically to the various hosts. When host operating system changes are needed, the host suppliers have complete ability to make all upgrades; field device descriptions are unaffected.

FDT/DTM technology development, recently undertaken by the FDT Joint Interest Group as an alternative, has goals described as similar to the DDL collaboration. However, Emerson’s review of the concept prompted concerns about important shortcomings for users in such areas as device choices, ease of use, integration of devices, and system upgrades. Emerson is therefore focusing its resources on enhancement and standardization of DDL. Click here to read more about the company’s position on these technologies .

In other certification/standards news, CiDRA Corp . has received Class 1, Div. 2 certification for its SONARtrac process monitoring system from Underwriters Laboratories (UL). The flowmeter is UL approved for use in hazardous environments containing volatile flammable liquids, gases or vapors. The sonar-based flow technology provides accurate, non-intrusive flow and sound speed measurement for single- and multi-phase flows. It detects the speed at which sound waves propagate within a pipe. Measured sound speed can be correlated precisely to the amount of air in the process fluid.

FLT Series flow switch from Fluid Components Intl . has received ATEX certification . Flex-Switch FLT93 flow/level/temperature series device with dual port enclosure has been approved by the European Community’s KEMA organization for use in potentially explosive environments classified as EX II 2G Eexd IIC T4. The thermal mass switch performs flow or level sensing along with temperature measurement simultaneously. Circuitry has two independent 6-Amp relays for precise switch point setting along with two voltage outputs: one for flow and one for temperature monitoring.

—Jeanine Katzel, Senior Editor, Control Engineering, jkatzel@reedbusiness.com