The industrial computer 400PLC (lower computer) adjusts and controls the field equipment and process parameters. Raw meal batching station and cement batching station use 486 industrial computer to form a centralized control frequency conversion speed regulation batching system. The use of industrial computer has improved the automation level of the cement plant. In order to ensure the normal operation of the industrial computer and avoid the "crash" of the industrial computer affecting production, the reasons for the common "crash" of the industrial computer are analyzed and countermeasures are found.
1. Hardware reasons
When the factory was established in 1997, the two Siemens industrial computers in the central control system were configured as follows: the central processing unit was Pentium 200MHz, the memory was 32M, and the hard disk was 1G. This configuration was relatively advanced at that time. Because of using Windows95 operating system and running WinCC control software system, the speed of IPC processing S7-400PLC information is relatively slow. During the debugging and operation of the cement plant, the industrial computer often "crashes". When the industrial computer processes more than 100 on-site signals transmitted by the PLC, the CPU frequency of the industrial computer is low and the memory is small, so it cannot recognize and process so many at the same time. signal, so that these signals "crash", causing the industrial computer to "crash".
Countermeasure: Due to the limitation of the memory slot on the mainboard of the industrial computer, the memory can only be expanded to 64M. The main solution is to reduce the frequency at which the industrial computer processes and recognizes the on-site signal, so as to avoid the signal "collision". The specific scheme is: when the industrial computer is connected to the on-site signal through the PLC, the signal sampling period is set to be more than 2s, and the analog signal with little change, such as temperature, can be set to more than 10s. In the WinCC programming process, after the sampling period of all analog signals is set to more than 2s, the phenomenon of industrial computer "crash" rarely occurs.
2. Ambient temperature
The raw meal and cement batching station uses the 486 industrial computer, which is more sensitive to the ambient temperature. When the summer is hot and the air conditioner is damaged, the industrial computer is easy to "crash".
Countermeasures: Repair the air conditioner, reduce the ambient temperature of the industrial computer, and ensure the normal operation of the industrial computer.
3. Poor heat dissipation inside the industrial computer
The environment where the industrial computer is located is harsh, in addition to the high temperature, the dust is also large. When dust enters the industrial computer, the heat dissipation effect of various boards, CPUs and other electronic components is poor, causing the industrial computer to "crash".
Countermeasures: Regularly remove dust inside the industrial computer and maintain good ventilation.
4. Check the CPU fan and the host power supply fan
The heat dissipation of the industrial computer is mainly carried out by the CPU fan and the power supply fan. When the CPU fan is damaged, the temperature of the CPU rises, which can easily cause the industrial computer to "crash". This phenomenon has occurred in raw meal batching stations.
Countermeasure: Check the fan of the industrial computer frequently, and replace the damaged fan in time. When the industrial computer in the central control room leaves the factory, only a heat sink is installed on the CPU, and there is no fan. After installing a special cooling fan, the temperature of the CPU is reduced by nearly 5 degree .
5. Frequently clean up temporarily generated files
When the industrial computer is running, it will generate a large number of temporary files such as Temp files, which occupy the hard disk and system resources and affect the speed of the industrial computer processing information. Regularly check the hard disk and delete temporary files to improve the speed of information processing by the industrial computer.
6. Frequent maintenance of the system
Due to editing control programs and other reasons, other application software is installed in the system. Too many application software will make the running speed of the industrial computer slower and slower. Therefore, do a comprehensive maintenance on the industrial computer every once in a while, click "Start" → "Programs" → "Accessories" → "System Tools" → "Maintenance Wizard", and then click the "OK" button to conduct a comprehensive maintenance of the industrial computer. maintenance, so that the industrial computer can maintain a better state. It is better to do a "hard disk defragmentation" every 1 month, after finishing, it can speed up the running speed of the program.
7. Industrial computer "crash" caused by information blocking
The industrial computer (upper computer) in the central control room monitors and controls the S7-400PLC (lower computer). When the information is blocked, the fault phenomenon is: "shadow" appears at the monitoring signal on the industrial computer screen and the signal values are all zero. Unable to monitor and control. This failure is not the same as the "crash" phenomenon mentioned above. The cause of the failure is caused by information blocking. The upper computer cannot receive the signal due to the "crash" of the lower computer or the failure of the transmission signal network cable and network card. In fact, the upper computer does not "crash". This kind of failure happened in early November 2001. Due to the poor contact between the network cable and the network card, the upper computer could not monitor and control the lower computer.
Countermeasure: When there is a "shadow" on the upper computer screen, first check the working status of the lower computer. There are various error indicators on the CPU template of S7-400PLC, which can be operated according to the status of the indicators. If the PLC is "dead", restarting the PLC's CPU with the key will return to normal. If there is a problem with the network cable and network card, the operator (or notify the electrician or the factory technician) should immediately check whether the signal cable plugs of the upper and lower computers are in poor contact, and lightly press or swing each plug by hand to find the fault. point to create conditions for factory technicians to come to the scene for diagnosis and treatment.
8. It is recommended to upgrade the industrial computer
At present, through the above measures, the number of "crash" of the industrial computer has been greatly reduced. However, due to the lower hardware configuration of the upper computer, the lower version of the software operation and control system, and the slower information processing speed of the upper computer, it is recommended to upgrade the industrial computer and increase the CPU frequency, memory capacity and hard disk capacity. In order to better meet the production needs, it is recommended to upgrade the CPU of the industrial computer in the central control room to Pentium 41.5GHz or above, the memory to be 256M, and the hard disk to be above 20G. At the same time, the operating software is upgraded to Chinese Windows98 or WindowsNT system, and the control software is upgraded to WinCC5.0 version. In this way, the speed of processing information of the industrial computer can be greatly improved, and the "crash" can be avoided.
