Process supervisor gets sequencing capability while in redundant mode

Citation

(2001), "Process supervisor gets sequencing capability while in redundant mode", Pigment & Resin Technology, Vol. 30 No. 5. https://doi.org/10.1108/prt.2001.12930eab.002

Process supervisor gets sequencing capability while in redundant mode

Process supervisor gets sequencing capability while in redundant mode

Keywords: Eurotherm, Process control

Eurotherm reports that it has enhanced the functionality of its recently introduced process supervisor distributed process controller by giving it the capability of performing sequence routines while operating in redundant mode. Described as a highly reliable unit, it features two independent processors, arranged such that if one processor fails then the other will seamlessly take over.

Process supervisor has evolved from, and fully complements, Eurotherm's T103 Unit Controller. The enhanced new system is said to have a fully configurable, open network architecture which allows simple interfacing to up to 16 Eurotherm Process Interface (2500 System) I/O modules as well as other third-party devices. By separating processing functions from the I/O section, the system allows physical distribution of the I/O modules, saving on wiring costs.

Built in support for PROFIBUS DPVI (as master), MODBUS RTU (both as master and slave) and advanced peer-to-peer communications on ALIN, Eurotherm's proprietary instrument networking protocol, is believed to have resulted in a truly distributable system. The unit is considered therefore capable of supporting Alin, Profibus and Modbus simultaneously.

When used for continuous control situations, an overall control strategy is built up by interconnecting function blocks from a large library of analogue and logic elements. The function block library includes control timing, logic, maths, etc. There is also a set of control module software blocks, based on the ISA-888 standard, representing physical plant equipment such as valves and pumps. These include all the fimctionality required to control a device in a single block. In addition to fixed function blocks, ACTION blocks support user algorithms written in ST (structured text).

Eurotherm reports that the sequential control capability of process supervisor, which can now function in redundant mode, allows the configuration of phases for batch processes as defined by the ISA-S88 process model. Sequence strategies are built using a powerful and intuitive SFC configurator, and act in a supervisory role relative to the continuous control mode. Multiple sequences can be loaded and unloaded as required to provide even more sequence flexibility without any adverse effect on the continuous control.

Further details are available from Eurotherm Limited. Tel: +44 (0)1903 268500; Fax: +44 (0)1903 695666; E-mail: info@eurotherm.co.uk; Web site: http://www.eurotherm.co.uk