A failure in the central control system
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This post was last edited by whwglp on 2012-7-29 09:12. On July 28, 2012, did the operating device stop suddenly? Checking the fault diagnosis information revealed a bus failure in the 02# main control card (the equipment stopped operating at exactly the time when this alarm was triggered) ； Check the control stations: The four main control cards in the 2 control station configurations exhibit intermittent FALL alarm indications (with an interval of about 2 minutes) ； However, the alarm messages are not displayed in the fault diagnosis information during this period ； Checking the history curve: A jump was detected in a custom one-byte variable that causes the device to shut down, but the factors affecting this variable were all normal ； Treatment: Based on the diagnostic information, it is determined to be a fault in Network A ； Disconnecting the A network one by one (to suppress the alarm signals from the main control card) results in the issue being caused by a specific operation station; by disconnecting the A network cable of that operation station, the system alarm is eliminated ； Confusion: A fault at the operational level should not affect the operation of the control layer. I really can’t figure out the actual principle or reason behind it; I’m just sharing this issue with everyone here ； This device has been in operation for 11 years. In terms of hardware, it features a large number of discrete components. It serves as the control system for an important set of equipment, with numerous interlocks. Apart from replacing the monitoring software, no other hardware components have been updated. I’m curious to hear what others in the industry think about the service life of DCS hardware
1. A failure of the network card or the network itself should not cause a shutdown of the control layer; that shouldn’t happen. 2. Has anyone checked the operator’s action logs to see if anyone modified those variables? 3. A network failure is a problem affecting the entire communication system, so those main control cards should flash. Each computer should have at least two network cards. Are there any other symptoms? Please share them
1. Regarding the first point mentioned above, I also believe that such a situation should not occur. However, a fault did arise, and it was not possible to simulate similar faults; therefore, only the actual, surface-level symptoms of the fault could be addressed before production could resume (production needed to start immediately)； 2. There are no issues with the operation records or any of the variables within the program ； 3. The flashing of all four main control cards at the two stations indicates a network failure in the common components; it shows that there is a fault on bus 0 of main control card 2# (this was not clearly stated earlier, please forgive me). This suggests a fault in network A or an address conflict. The equipment continues to operate, with no other devices connected to it, and no one has entered the system to change addresses; therefore, it was possible to quickly identify that the network card of one of the operation stations is faulty ； 4. One operation station is equipped with three network cards: one of them is used for data recording and transmission (to ensure that the curves recorded by each operation station are error-free), while the other two are connected to networks A and B respectively. When connected to either network A or B, an alarm indicator should appear on the monitoring screen of the operation station; however, in reality, an alarm is only displayed when connected to network A or B. There is also one operation station for which no alarm is triggered regardless of whether it is connected to network A or B. The exact reason is unknown, and further discussion is needed with the manufacturer ； 5. This DCS system is of the JX-300x type; it was put into operation in 2001. The operating system used evolved from NT4.0 to WINDON2000, and the monitoring software was upgraded from version 3.12C to 3.16 in 2004. There were some issues with the historical data during that period, but these were resolved after applying updates to the control system ； In 2007 it was upgraded to AdvanTrolPro (V2.5), with patch SP06; it worked fairly well ； But this time, I’m not sure if it’s due to a software conflict or prolonged system operation that caused these negative effects ； If for no other reason, then something that was impossible has happened – it’s confusing! I really want to find the root cause theoretically, and I hope my colleagues can offer more suggestions and ideas
Our factory’s JX-300x urea system has also been in use for 8-9 years. Last March, it was upgraded from version 3.16 to AdvanTrol Pro V2.65, and the operating system was changed from WIN2000 to XP. It has been in use for over a year now without any problems. . . Or a software conflict. It seems the original poster has quite strong technical skills; could it be a problem with the equipment being used? . . . The stability of the DCS system is quite good. “4. One operation station is equipped with three network cards, one of which is used for data recording and transmission (to ensure that the curves recorded by each operation station are error-free). Is there an engineer station serving as a historical data server? . . Do other operation stations read data from the engineer station? ? ? Every control station in our factory keeps records, and it’s the same everywhere. . It’s just that the operation records vary for each operation station.