250 PArt | II Test and Measurement same specification as the communications for device config- uration and maintenance, strategy building and device man- agement, as well as network management, can be performed from the same single software tool. in the case of the Smar SYSCoN software, this means that users can drag and drop from the strategy directly into the devices. imprecise mechanics and simple analog electronics, have been unable to respond to demands in position change by less than a few percent. Modern positioners such as the Smar FY302 use a noncontact position-sensing method that eliminates mechanical linkages, and they perform all characterization and positioning algorithms in software, thereby being able to modulate with a precision of a fraction of a percent. 19.12.7 measuring directives it is likely that many process measurements that at present are not subject to weights and measures surveillance will become so in future. directives requiring further integration of diagnostic routines into these instruments, data backup, and so on are to be expected. 19.12.9 Integration of Intelligent transmitters into Instrument management systems The situation is quite different when we consider the advan- tages to be gained from integrating information from a number of intelligent transmitters into the management system. The real benefits from the use of intelligent transmitters arise from the fact that so much basic data regarding the transmit- ter itself, such as the model number, serial number, tag, loca- tion, materials of construction, and so on, and its application, such as the zero and span, units of measure, and damping, are stored in the memory of the transmitter electronics and can be accessed via the two-way communication system. For an individual transmitter operating in a 4­20 mA mea- surement loop, this means that its identity can be identified and its operation monitored from any junction box or set of terminals in the measurement loop, thereby avoiding the need to gain access to the transmitter itself to check its status or to make an adjustment to its operating range. if, however, the transmitter is connected directly to a fieldbus, together with other transmitters and actuators, as shown in Figure 19.38, the same information can be accessed at any junction on the fieldbus or via an interface unit. This opens the opportunity to collect data from all the sensors and actuators in the control system and analyze that data using a variety of statistical and knowledge-based techniques, to optimize the maintenance and technical management of the process plant. 19.12.8 Further developments of Intelligent transmitters The accuracy and versatility achieved by the present gen- eration of microprocessor-based and intelligent transmit- ters is such that there is little real advantage to be gained from further improvement in these respects. For temperature and differential pressure transmitters for which accuracies of 0.1 percent of the measured value are claimed, the point has been reached where it is necessary to question whether the transmitted signal has the significance implied by the number of digits in the displayed value. For most process measurements, the noise component can range from 1 percent to 30 percent of the mean value, and the damping applied may be anything from 1 to 60 s. it is then necessary to consider how realistically the displayed value represents the process variable. The focus has now shifted toward the valve positioners that until now have been contributing significantly to signifi- cant process variability. Until recently positioners, due to their FIgure 19.38 Typical arrange- ment of the equipment connections to a fieldbus.