Yokogawa Electric Corporation announces the release of the UT551 Digital Indicating Controller, a product that enables users in fields ranging from production to research and development to acquire temperature, pressure and flow rate data and to make changes to controller settings via an Ethernet connection. Also being released today is an Ethernet-enabled version of the GateMODBUS*1 interface component for the DAQWORX Data Acquisition Software Suite. This product allows users to establish an Ethernet link between the UT551 and the DAQWORX software running on a PC or some other host system. Both products are targeted at production equipment and machinery operators in practically every industry including automobiles, electronics, machine tools, chemicals, and foods as well as at operators of in-plant equipment and facilities such as air conditioners and motor-driven equipment.
*1 Modbus: A control protocol developed and made public by Modicon Inc. (AEG Schneider Automation International S.A.S) that is used widely in the industrial automation field.. 

Development Background
In plants, a variety of measurement data such as temperature, pressure, and flow rate as well as data on equipment operation are monitored and controlled using digital indicating controllers. Till now, digital indicating controllers have had to be connected to a programmable logic controller (PLC) or a conversion adapter had to be used to send information to higher-order systems such as a production control system. The UT551 has been developed in response to a growing demand for the capability to simultaneously monitor and control two or more plants not only from a monitoring room but also from remote locations such as an office, and it enables this without any sacrifice to cost-effectiveness.

Product Features
1. Ethernet-enabled controller
• Employs the Modbus/TCP protocol*2 and is equipped with a 10BASE-T interface
• Enables parameter settings to be changed and data to be acquired through an Ethernet connection
*2 Modbus/TCP protocol: A protocol in which the Modbus protocol is adopted as the TCP protocol for an Ethernet

2. The first controller in the industry to support a gateway function
The conventional UT351 Ethernet-enabled indicating controller was designed to allow a host system such as a PC to access it via Ethernet; non-Ethernet-enabled indicating controllers or peripheral devices could not be accessed. Thanks to the incorporation of the gateway function, it is now possible for a PC or any other host system to access non-Ethernet-enabled indicating controllers or peripheral devices*3 by simply connecting them to the UT551.
*3 “Non-Ethernet-enabled indicating controllers or peripheral devices” refers to controllers or devices equipped with communication functions that are compliant with the RS-485 protocol and use the Modbus/RTU protocol.

3. Futuristic control functions
As standard features, the UT551 includes a “SUPER” function that suppresses the effects of changes in operating conditions and/or unexpected disturbances and overshoots arising from insufficient control parameter tuning, and a “SUPER 2” function that suppresses hunting (periodic vertical oscillations).

4. Readings provided by active display
In the event of a failure, an alarm is triggered and the display measurement indicator changes automatically from green to red, communicating the control status to the operator at a glance.

Yokogawa's Approach Toward This Field
Yokogawa developed the first distributed control system (DCS) and has been leading the way in the world’s control systems industry ever since. The company entered the temperature controller market in 1987 and in 1991 became the first in the industry to incorporate a fuzzy logic-based hunting-suppression function into its products. Following the 1997 transfer of business operations to Yokogawa M&C Corporation, Yokogawa developed the Ethernet-enabled UT351 controller.
In April of this year, the control business of Yokogawa M&C, including its temperature controller product line, was integrated into Yokogawa in order to strengthen product development and increase sales efficiency. To serve its customers’ needs and boost its operations in this business area, Yokogawa will continue to focus on introducing state-of-the-art technologies and expanding its lineup of temperature controller products.