免费人成视频19674不收费

    <tbody id="ofkqm"><pre id="ofkqm"></pre></tbody>

    1. <dd id="ofkqm"><noscript id="ofkqm"></noscript></dd>

        1. <dd id="ofkqm"><noscript id="ofkqm"><video id="ofkqm"></video></noscript></dd>
        2. Home > Operational Area > ELECTRICAL & DCS
          Problems in the application of DCS system

          1. Dispersion of faults: At present the DCS system has not realized dispersion of faults of true sense, on one hand this is because the current device is still more expensive, the control system cannot be dispersed geographically(approach to the traditional instrument control system as far as possible).The  field conditions of industrial control generally is badly, it is still difficult for the remote I/O cards provided by the current vendors to adapt the dust, temperature and humidity. On the other hand, the control functions in design are not enough dispersed, including the design of DCS system and project design. For example, MOD - 300 system, and its I/Os are  too concentrated, the faults of I/O card fault will affect the normal work of the system. In addition, the auxiliary control of the unit is done by programmable logic controller (PLC )system, GATEWAY is used for the communication of PLC and MOD - 300 system , the GATEWAY becomes one bottleneck of the whole control system, once it fails, and it will affect the normal operation of the unit. In addition, the controlled objects contained in MFP are too much, one piece of MFP card failure will affect the normal work of quite a lot of control circuit. The control system like this design is bound to have higher requirement on the reliability of cards or systems.

          2. Real- time. The process control requires the control system to have very high real-time. Due to the limitation of communication technology and computer technology, the current system still has to be improved in real- time, such as the early MOD - 300 system, for operating one valve,  it requires more than 10 seconds from when the operator presses the key to issue commands to when the feedback signal  is seen on the screen. Later, after upgrading the hardware and changing into a new generation of chips, the problems are solved. Because the pictures are opened slowly, for some systems, to operating one device required switching several images, in an emergency situation, the operator feels very inconvenience. In addition, the time needed for communication (or the response time of DCS system) deteriorate the characteristics of the controlled objects, making the quality indexes of the transition process of the closed-loop system decrease.

          3. The convenience of configuration and the necessary protection of permission. Regarding system configuration, the current DCS system mostly uses computer window technology, generally speaking, it is convenient, but in aspect of line configuration, there are still problems to study. Most systems are configured in engineer station, then are downloaded to the control subsystem or the control card pieces, and this process takes long time, especially during debugging, it is common to modify the configuration, it is required to seek one convenient and safe on-line configuration method.

          4. Manufacturing process and installing process. The manufacturing process and installing process are very important factors to affect the normal use of DCS system. Sometimes just because of the bad small plug-in quality and poor contacting, a major fault or accident happens. The hardware manufacturing process  provided by some systems is unsatisfactory, the cards and connectors are not reliable. Some cards have failure. Sometimes pulling, inserting and shaking the cards can make the failure disappear. This aspect is one problem that DCS manufacturers must attach great importance. If the systems provided  cannot meet the requirements of reliability in process, then they are hard to be accepted though they are attractive in principle. On the other hand it is the installation process that is one aspect to be further studied in application technology of DCS system.

          5. The reliability and maturity of the application software. The application practice of DCS system is still in the practice of continuous accumulation process, many application software are not very mature, and their reliability are to be tested by time. In this aspect, the DCS system manufacturers shall strengthen the study in order to make DCS system that has been put into use or will be soon put into use have enough reliability.


          Favourite