Safety and control from Japan
Yokogawa has a slew of new products for safety monitoring and process control

Safety instrumented systems (SISs), which oversee distributed process control (DCS) and other systems to ensure a high degree of safety at all times, are traditionally separate from the systems they protect. A new SIS from Yokogawa breaks this mould because it can be fully integrated with a DCS.

The ProSafe-RS safety system can be integrated with Yokogawa’s Centum series of process control systems, eliminating for the first time the need to build process control and safety systems separately. As a result, plant information can be managed centrally, and the integrated information contributes to greater operational efficiency and safety. ProSafe-RS monitor the status of the plant and shuts it down a plant whenever an unexpected condition is detected.
Yokogawa entered the SIS business in 1997 with the launch of the ProSafe series, which comply with the IEC 61508 international standard. Because their roles and functions are different, process control systems and safety systems have traditionally been constructed separately. However, says the company, there is a growing need to integrate the two systems in order to centralize plant information management. ProSafe-RS also meets the need for SISs that are more reliable and more flexible than their predecessors.
ProSafe-RS can share a network and operator station, as well as plant data,
with a Centum DCS. Safety and operability are improved because operators are
working in a familiar environment; for instance, alarms from both the SIS and the DCS can be displayed simultaneously on a single screen. The basic non-redundant system has been certified to SIL 3 by
TÜV Rheinland/Germany, with various
redundancy options to improve reliability still further. ProSafe-RS is the world’s first safety system to receive SIL3 certification under IEC 61511.

Centum upgrades
To support the new ProSafe-RS safety system, Yokogawa has upgraded its Centum CS 3000 R3 Integrated Production Control System to Release 3.06. As well as being fully compatible with ProSafe-RS, the new CS 3000 is cheaper to set up and maintain than its predecessor, says the company.
A new System Integration OPC Station (SIOS) allows a CS 3000 system to easily monitor process data and event messages from other control systems. Because it uses the industry-standard OPC interface, this functionality can be added without adding significantly to the engineering work required for tasks such as the configuration of data integration. For example, the operator of a CS 3000 controlling a plant’s upstream operations can now use this system to monitor downstream operations controlled by another control system.
Integration with the Centum CS 1000 control system has also been improved. It is now possible to convert a CS 1000, which is intended for small- and medium-sized plants, to a CS 3000 without modifications or hardware additions. When the plant outgrows the CS 1000, the expanded functions of the CS 3000 can simply be
added.
The CS 3000 system is a core building block of VigilantPlant, a new initiative promoted by Yokogawa under its Vigilance campaign, which began in 2003. Launched by Yokogawa President and CEO Isao Uchida at the ARC Forum in February,
VigilantPlant brings together Yokogawa’s existing products and services for plant optimization. Through the motto “See Clearly, Know in Advance, and Act with Agility”, VigilantPlant aims to eliminate unplanned downtime, improve asset utilization, and help businesses adapt to shifting market conditions and customer demands.
Analyzers and recorders
Sophisticated control and safety systems are of little use without instrumentation to match, and in this department Yokogawa has several new offerings. The new EXA450 family of pH and conductivity analyzers combine a versatile new user interface with powerful communications and control functions. Each instrument has Hart communications as well as two 4–20 mA outputs and four SPDT relay contacts.
The EXA450 family includes three 4-wire models: the PH450G pH/ORP analyzer, the SC450G conductivity/ resistivity analyzer, and the ISC450G inductive conductivity analyzer. High accuracy and integrity are guaranteed by advanced temperature compensation algorithms and dynamic sensor checking.
The new user interface uses a backlit greyscale dot-matrix LCD combining simple operation with easy access to process and diagnostic information. All information is displayed in plain, easy-to-understand text with no abbreviated words or
coded messages. Operation is via context-sensitive buttons on a robust membrane-protected touch-sensitive screen. The rugged and watertight field housing, measuring 144 mm on each side, has the same dimensions, mounting arrangement and termination details as Yokogawa’s earlier EXA400 and EXA402 series.
The temperature compensation function of the pH meter has significant benefit in pure water applications that are common in the power generation industry where the dissociation of water molecules can introduce temperature related discrepancies between field and laboratory test results.
Other features include pre-defined buffer solutions, three sets of pre-loaded pH buffer standards, a trending display for up to two weeks of data, and on-screen logbooks for the storage of calibration data, configuration changes and events.
Yokogawa has also launched a new
100 mm chart recorder, the µR10000, as a successor to the µR1000, which dates from 1992. The µR10000 provides the same functionality as the µR1000 but is more reliable, weighs less, and consumes less power. Its large dot-matrix vacuum fluorescent display is very flexible in operation—it can show numerical values and bar graphs simultaneously, for example—and simplifies initial setup.
Traces can be compressed or expanded as required, for better recording of data under different conditions. Charts can also be divided into recording zones to record trends. It is also possible to print measured data, points of alarm occurrence/cancellation, and messages. RS-422A/RS-485 interfaces are standard, with Ethernet compatibility as an option