[Daily Question 20090203] Contents of daily maintenance of DCS operating system and issues to pay attention to

HollySys MACSV has a monthly maintenance plan~~· Every week, the computers in each workshop are shut down for one day, the computer is disinfected once a month, the project file is saved before each change of the project, the monthly server history is compressed and saved, and the ground resistance is measured once every three months~ The network equipment is regularly powered off and restarted~ Stop the car to do UPS switching test, main control switching test, these are what come to mind~

First, pay attention to the cleanliness of the engineering station. Do not sweep the floor, but use a vacuum cleaner. Frequently wipe the dust on your computer and desk. Second, you can use the hard disk as a spare disk. If one of the hard disks breaks down, you can immediately switch to the spare disk. Third, use the maintenance time to carry out dust removal, inspection and other work. It is strictly forbidden to modify or disassemble the machine without authorization. It is strictly forbidden to use non-genuine software. Use foreign floppy disks or CDs with caution to prevent virus intrusion.

1. User security management 2. Configuration change management 3. System performance report 4. Scraping system for consumables (printers, LCD screens, ordinary PCs, etc., it is best to scrap them in advance if their lifespan is limited, and there is no need to wait until they can no longer be used before replacing them)

1 Daily maintenance work 1.1 Process channel faults The most common process channel faults are I/O card faults.: The general judgment and treatment of I/O card faults are through system diagnosis, replacement of channels or replacement of spare parts. As for the damage caused by the aging of its internal components or other reasons, it is difficult for general thermal control personnel to judge. The maintenance of I/O cards is generally handled by the manufacturer. The current thermal control maintenance personnel cannot perform maintenance like conventional instruments. Moreover, manufacturers' I/O cards have become integrated, so only spare parts can be purchased. Fortunately, this type of fault only occurs more often during the debugging stage, and the probability of occurrence during normal operation is very low. Failures of primary components or control equipment sometimes cannot be directly discovered by the operator, and thermal control personnel are notified only after an abnormality or alarm occurs. In this way, the quality requirements for maintenance personnel and operation personnel must be improved. The operation personnel must introduce the status before and after the fault in detail so that the thermal control maintenance personnel can quickly and accurately handle the defects and reduce the expansion of the fault. In addition, many DCS manufacturers support hot-dipping of cards in product promotion. As controllers, safety protection measures must be taken when replacing cards during operation, otherwise it will cause system changes or load changes, especially digital cards. 1.2 There are related reports on operator station crashes, regardless of domestic or imported equipment. There are many reasons for this, such as hard disk or card failure, cooling fan overload, etc. Sometimes human operation phenomena occur. Generally, when modifying the control logic and downloading software to restart the equipment or forcing equipment protection signals, operational events are most likely to occur, ranging from equipment abnormality to serious equipment outage. ； For restarting after a crash, different manufacturers have different start-up times, ranging from tens of seconds to several minutes. Human-made faults for this operation account for a large proportion of unsafe events in the thermal engineering profession. Special attention should be paid to reducing human faults during operation. 1.3 The abnormal operation of the ball mark is generally caused by the long-term operation of the mechanical device, aging, pollution, unreliable point on and off, weak cable plug-in, etc. It needs to be replaced and inspected. 1.4 Control operation failure: It is because the operating signal of the ball mark does not change the state of the process channel normally, causing the operation to fail. This is caused by two aspects. One is the software defect, and the other is the faulty state of the hardware itself. For such defects, it is common practice to check that the function of the process channel is normal, and then check the operation again and restart the initial operation if necessary. 1.5 For membrane keyboards, the main reason is poor keyboard contact, loose signal cables, or the host mistakenly operates the keyboard or incomplete startup, which can lead to abnormal function. Applications are handled according to different situations. 1.6 The reason why the printer does not work is generally due to configuration reasons. If such a fault occurs, you should check whether the printer settings and its hardware are normal and handle them properly. The weak function of the report software is mainly caused by the printer crashing when printing reports and SOE, or the SOE record time of the printer does not match the actual situation. ； SOE cannot return to historical curves after printing and browsing ； The SOE time sequence is inconsistent and sometimes has a large deviation, which will delay the progress of the accident analysis and sometimes mislead the direction of the analysis. The SOE problem is not only related to the unreasonable system design and the SOE points are not completely concentrated on one DPU, but also related to the insufficient consideration of the system hardware and software design. The occurrence of this kind of fault, through analysis, is believed to be mainly due to the imperfect consideration of the overall aspects of the power plant. In small aspects, such faults may occur because of not being careful enough. This situation must be taken seriously, not letting go of any clues, and carefully studying with the manufacturer to propose problems for further improvement, so that the system can better serve production. 1.7 Power failure: There are many problems with power supply failure. The insurance configuration is unreasonable, the backup power supply cannot be switched on automatically, power fluctuations cause protection malfunctions and poor plug contact can easily lead to no power supply. Troubleshooting a power failure is relatively easy. First of all, carefully check the configuration and capacity of the insurance to truly play the role of insurance ； Secondly, the configuration of UPS is very important. It can ensure the normal power supply of the system even when the power supply fluctuates, and redundancy and backup issues must be considered. 1.8 Failure caused by interference: Interference is mainly caused by grounding issues, backup power switching and high-power wireless communication equipment such as mobile phones and walkie-talkies. In addition, the interference signal of the DCS system may be caused by itself. Then the grounding problem of DCS systems has attracted more and more people's attention, especially in the power industry. The starting and stopping of high-power electrical equipment will interfere with the control signals of DCS and cause unnecessary faults. In order to prevent interference signals from entering the system, shielding and grounding requirements and methods must be strictly implemented, signal lines must be kept away from interference sources, and measures to prevent power supply fluctuations must be taken. When the unit is running between the master/slave process processors, unless absolutely necessary, try not to artificially switch to prevent interference. If switching is necessary, measures should be taken to manually switch the control first to avoid affecting the operating conditions of the unit. The use of high-power radio communication equipment should be absolutely prohibited in key locations such as electronic equipment rooms and engineering stations. 2． Operation management The operation management of the DCS system refers to the inspection of the system, the commissioning and withdrawal of thermal protection, and the supervision and management of DCS software and hardware. 2.1 Software backup management, application software (database) should be backed up in a timely manner, and minimal changes can be recorded. ； Modifications to the database should be saved to the engineering station at the same time, and should also be saved to a floppy disk or other hard disk. However, please note that the backup disk should not be used beyond the expiration date to prevent data loss. 2.2 Software inspection and functional testing should be carried out in accordance with the general methods of computer equipment, mainly to check the settings of permissions at all levels.: The use of non-DCS software is strictly prohibited: Configuration by unauthorized personnel is strictly prohibited. 2.3 The work ticket system should be strictly implemented for the operation and withdrawal of thermal protection. When overhauling a certain operating equipment, correct isolation measures should be taken to prevent cross-reaction of related equipment. In view of the above common faults, in order to avoid the occurrence of faults and reduce the number of occurrences, a strict inspection, maintenance and regular inspection system should be formulated, the DCS equipment inspection card should be carefully filled in, various small defects should be discovered and dealt with in a timely manner, so that faults disappear in the bud, and the operation log should be filled in to strengthen management methods.

DCS/ESD is an important control system for production equipment. The stability, reliability and safety of DCS/ESD electrical equipment need to be guaranteed by a strict management system. A complete set of organizational and technical measures for DCS/ESD system management should be established. The ESD system should formulate emergency response plans. The management regulations are as follows: Hardware management ； Software management (database, system configuration, constant changes) ； System security management. The main tasks of daily maintenance are as follows: ； 1. Whether the UPS power supply status is normal and discharged regularly 2. Whether the various power outputs of the DCS/ESD system cabinet are normal 3. Whether the controller, I/O card, safety barrier, communication card, switch, etc. are normal 4. Production history database and batch database are regularly backed up and saved 5. Cabinets and PCs are regularly dusted 6. DCS and ESD system grounding systems are measured regularly 7. Make various inspection and maintenance records