Technical staff first recommendation: DCS general troubleshooting manuals

DCS general fault repair work instructions for a factory

       DCS is responsible for the company's major production tasks and is the key equipment for instrument maintenance. In order to ensure the safe operation of these instrumentation equipment and to perform repairs quickly and effectively after a failure, this DCS fault work instruction manual is formulated.

One: Operation station failure

        As a man-machine interface, the operation station is the main equipment for the operator to monitor the production site. It is the most frequently operated part and the most prone to problems.

1 , operating station hardware failure: Operating station hardware failure mainly refers to the computer hardware failure, including the host, monitor, mouse and keyboard and other peripheral equipment, maintenance, mainly based on the phenomenon of failure to take the replacement method and exclusion. Specific steps are as follows:

A. Make backup of DCS software system software and configuration files;

B. Observe DCS operation station to display fault information or phenomena, and initially determine where the fault is.

C. Turn off the computer and monitor power, and unplug the power or air switch;

D , with anti-static gloves, replace the faulty hardware;

E. Turn on the power and start the computer to determine if it is normal.

F. If the process is normal, the DCS operation station is put into use and observed for 24 hours. If it is not yet normal, continue to perform the above steps until the cause of the fault is found and dealt with.

2. Software failure of the operation station : Software failures of the operation station mainly include operating system software failures and DCS system software failures. These types of failures are most likely to occur and are often handled. The specific processing steps are as follows:

A. Make backup of DCS system software and configuration files;

B , ready for operating system software, hardware driver software (including video card, sound card, network card, mouse, etc.), DCS system software;

C. Restart the computer to see if it can return to normal. Most of the problems can be restored to normal.

D. If it does not return to normal, it is the cause of the operating system or the cause of the DCS software. If necessary, reinstall the corresponding software. In particular, it must be pointed out that the installation must be performed according to the installation instructions and the installation requirements of the software must be met. For example, how many versions of the operating system need to be patched;

E. Restore the configuration file to the DCS operation station and start the operation station. Observe for 24 hours.

II: Control station failure

        The control station is the core component that directly participates in the control. The main faults are controller failure, I/O card failure, channel failure, and power failure.

1, controller failure

The DCS controller is the core of the control station and is generally redundant. If the controller fails, the entire control station will be unavailable. The following troubleshooting process is as follows:

A , contact the craftsman to make a parking plan;

B , ready to replace the controller;

C. Make a backup of the configuration data.

D , wear anti-static gloves;

E. Pull out the bad controller and replace it with a good one.

F , upload the configured data;

G. Synchronize the data of the main controller and the redundant controller.

2. I/O card faults

I/O card faults include I/O processing cards and terminal board failures. Processing steps:

A. Contact the craftsman to cut out the meter related to this faulty card and change the manual control at the scene;

B. Finding where the fault occurred is an I/O processing card fault, a terminal fault, or a connection cable fault between them;

C. Prepare corresponding accessories.

D , wear anti-static gloves;

E , replace the card;

F. Observe the operation of the card. If there is no problem, contact the technician to use the instrument loop.

3 , channel failure

The main reason for the failure of the channel is the on-site strong power entry, the burnout of the channel components or the fuses. If the fuse is broken, replace it. If the channel components are damaged and cannot be restored in a short time, the channel can be replaced. Proceed as follows:

A , find free channels;

B , change the channel connection line;

C , change the configuration to the new channel;

D , investment instrumentation.

4 , power failure

        The power system is an important guarantee for the reliable operation of the DCS. It supplies power to the controller and I/O cards. Generally, it has redundancy. The troubleshooting steps are as follows:

A , ready for standby power;

B. If you can power off the power, you can turn off the power switch. If you can't power off, you must pay attention to prevent short circuit. At the same time, you should pay attention to the positive and negative of the DC power. The AC power must be in the same phase, otherwise it may burn the power and cause equipment damage.

C. Use the power supply and check the output of the power supply with a multimeter.

Three: Communication failure

The communication of the DCS includes communication cables, communication cards, and failures of communication cables with high failure frequency.

1, the failure of the communication cable

The fault of the communication cable includes the fault of the terminal connector and the fault of the cable body. The processing steps are as follows:

A. Test the cable and determine whether the cable is normal. If not, replace the cable. If the cable is normal, check the terminal connector to see if the connector is loose, whether it is rusted, contact is not good, and the communication failure and error are caused. Increase in rate;

B. Use special tools to tighten joints or special cleaning fluid to remove rust;

C. Clearing the error rate on the DCS is 0. Observe whether the error rate value increases. If it does not increase, it means that the error rate is normal. If it still increases, check if there is a large source of interference around.

2. Failure of communication cards

        Communication cards include operating station communication cards and control station communication cards, dedicated communication cards and universal Ethernet cards. The processing steps are as follows:

A. Power off the device where the communication card is located;

B , first check the communication card parameters are set correctly, if not correct, change the parameters, if correct, you can use the test software to test the communication status, if it is a communication card failure, replace the communication card, and set the correct parameters.

Four: maintenance equipment and materials

No. Name Quantity Remarks

1 anti-static gloves 1

2 digital multimeter 1

3 adjustable wrench 2

4 straight screwdriver 2

5 Phillips screwdriver 2

6 brushes 2

7 mobile hard disk 1

8 DCS spare parts set

9 DCS data set

Five: maintenance precautions

DCS system as a large instrument control system, it relates to the safe production of the branch, such as improper repair, will have very serious consequences, continue to affect the production, it is possible to expand the fault, causing greater losses, according to the DCS system Characteristics, pay attention to the following items when performing maintenance on the DCS system:

1 , DCS configuration data are many, such as the configuration data is lost, the workload of the reconfiguration is huge, so the configuration data and system backup should be made before the overhaul;

2. A set of DCS system involves a lot of devices and positions. It must contact the technicians to make an accident handling plan. When there is a problem in the inspection, the technicians can ensure the safe operation of the device.

3 , DCS uses large-scale integrated circuits, static electricity is a great harm to it, so in the maintenance must wear anti-static gloves or handle static discharge;

4 , maintenance must be careful, careful, detailed maintenance procedures, to seize the fault, can not get the wrong card or cable, causing the entire DCS system to crash;

5 , DCS system equipment failure, the main method of elimination, and maintenance is very complex, so we must prepare adequate spare parts.