Distance learning improves IQ
Remote interrogation and control technology is bringing increasingly high levels of sophistication to virtually every piece of equipment, and the valve actuator is no exception.Digital technology has radically changed the equipment available to the water industry on both macro and micro levels. On the smaller scale, it has enabled Rotork to develop the 'intelligent' IQ valve actuator.
Based on the original IQ actuator, the company believes the latest IQ is significantly improved. The electronics have been rationalised, separate components have given way to application-specific integrated circuit (ASIC) technology which will support diagnostic and communication functions. The IQ's chip replaces more than 500 individual components and incorporates the actuator's main measurement, data-logging and processing activities. Standard actuators have a single printed circuit board to support all local and remote control functions.
A sense of history
The data logger stores historical operating information as well as activity and output torque profiles. This information, plus commissioning settings, valve position and status, is stored in the actuator.
Data can be accessed directly or remotely using an infra-red commissioning and interrogation system in conjunction with the company's IQ-Insight software. IQ-Insight is a graphical user interface which allows set-up and re-configuration as well as data harvesting. The interactive application is browser-based and runs under Microsoft Internet Explorer 4. Internet browser features such as links, bookmarking, 'back' and 'forward' controls and history are intended to make data analysis simple. A laptop can be connected to an actuator via an Infra-red Data Association (IrDA) interface, alternatively a fixed-site PC running IQ-Insight can communicate with the actuator, via a modem and cell phone. The device will also support 'point and shoot' commissioning.
The IQ is compatible with Pakscan two-wire fieldbus control and supervisory systems and can be specified for direct communication with contemporary open protocols including profibus, foundation fieldbus and modbus. The new digital innards mean online support is possible using the manufacturer's Customer Lifetime Care Facility.
Users can obtain local and remote setting indication, even if the mains power supply is interrupted. A battery maintains transmission of the information and a simple incremental encoder continually updates the actuator's position processor. When mains power is off, position data is retained in the non-volatile EEPROM memory and the indication relays are mechanically latched in the last-driven position. If the hand-wheel is moved with the power off, the encoder 'wakes up' the battery power circuit and the data in the position processor is updated. The unit can run on a three-phase, single-phase or DC power supply.
Torque control is handled by a piezo-resistive device embedded into a pad of silicone rubber. This senses forward and backward pressure from the motor shaft when it is working hard to turn the worm-wheel, giving an accurate indication of torque. Tests have confirmed highly repeatable results during complete life cycle tests at diverse temperatures.