PLC Communication Fault Diagnosis

PLC communication failure of SCR system made the whole winch system unable to operate. After fault diagnosis and treatment, the system returned to normal.

At about 11 pm, the driller was pulling out of the hole. Suddenly, the winch stopped, all the indicators on the control box in the driller's room went out, and the driller reported that the system could not be used. Rushed to the driller's room in time to check. It was found that the et200 communication module of the driller's room control box reported a red light fault, but the power supply of the power module was normal. According to the fault phenomenon, it was judged that it should be the communication fault of the PLC system. Immediately go to the control room to check the cup status. The CPU fault indicator lights up to display the communication fault.

1. Because there is no computer software and program, the location of the fault point cannot be viewed directly, so it can only be checked one by one.

According to experience, the communication cable from PLC control panel to driller's room is easily damaged when it is often moved, and the connectors at both ends are often plugged and loose. Therefore, the 2-terminal plug was checked first, and the communication cable was measured with a multimeter. As a result, the cable connector and cable were not damaged or loose. After plugging in, the test communication fault still exists.

2. In this case, you can only check one by one from one end of the communication to the other end.

Since the frequency converter is one end of communication, first check the first section of cable from the frequency converter to the touch screen in the control room and the communication plug. The cable connection and disconnection are normal and the connector resistance is normal. Then check the communication cable and connector from the touch screen to the CPU in the second section. The cable is connected and disconnected normally and the connector resistance is normal. Then check the communication cable and connector from CPU to the external plug of SCR room, and the cable is connected and disconnected normally. Check the cable and connector from the station communication module et200 in the driller's room to the touch screen in the driller's room. The cable is connected and disconnected normally. It is found that the connector of et200 is grounded and the resistance value is normal. Therefore, it is considered that the grounding affects the communication, so the other cable connected to the repeater is temporarily removed for communication test, and the fault still exists.

3. At this time, it can only be judged that there may be a problem with the hardware module.

Therefore, inertia thinking judgment may be that the communication module et200 may be damaged, so replace a new et200 module immediately, and the test fault still exists. Randomly judge that there may be a problem with the CPU. Replace a CPU for testing, and the problem still exists.

4. Considering that the communication cable may be disturbed, a temporary cable from CPU to remote et200 communication module is simply used, but the problem still exists.

5. Finally, considering the grounding problem of et200 module, although the resistance value is normal, it may damage small internal electrical components, so the communication connector of et200 is removed for re inspection, and it is found that there are abnormalities. This situation rarely occurs at ordinary times, so it is felt that there may be a problem during inspection, and a new PROFIBUS communication connector is replaced. And power on the test, and the communication returns to normal. Remove the zero hour cable and use the original communication cable. The communication is normal.

PLC Communication Fault Diagnosis 1

get in touch with us
recommended articles
FAQ
What Is an OLED Display? This Article Teaches You to Understand the Difference Between LED Backlight
LED backlight refers to the use of LED (light emitting diode) as the backlight of LCD, while LED backlight display is only the backlight source of LCD, which is transferred from traditional CCFL cold light tube (similar to fluorescent lamp) to LED (light emitting diode). The imaging principle of liquid crystal can be simply understood as that when the external voltage is applied to deflect the liquid crystal molecules, it will block the transmittance of the light emitted by the backlight like a gate, and then project the light into the color filters of different colors to form an image.The transition of backlight module from CCFL to LED can bring many benefits, which can make the brightness of the display screen more uniform, the product power consumption is lower, and the shape can be lighter and fashionable. However, w-led (white LED) backlight is widely used in the market. In fact, this backlight only replaces the luminous components, and the improvement of display effect is very weak or even not improved. Rgb-led (three color LED), which has significantly improved the display effect of LCD products, has significantly improved the display effect, but at the same time, the production cost is high, so it is applied to high-priced LCD TVs. At present, the LED display mentioned by businessmen refers to the display products with white LED backlight. The difference between it and ordinary LCD is the change of backlight.LED display screen integrates microelectronics technology, computer technology and information processing. It has become the most advantageous public display media with its advantages of bright color, wide dynamic range, high brightness, long service life, stable and reliable operation. At present, LED display screen has been widely used in large squares, commercial advertisements, stadiums, information dissemination, news release, securities trading, etc, It can meet the needs of different environments.LED display is a display mode by controlling semiconductor light-emitting diodes. Its general appearance is composed of many usually red light-emitting diodes, which display characters by turning on and off the lights. A display screen used to display text, graphics, images, animation, market, video, video signals and other information.OLED display is considered as the emerging application technology of the next generation of flat panel display because of its excellent characteristics such as self illumination, no backlight, high contrast, thin thickness, wide viewing angle, fast response speed, flexible panel, wide temperature range, simple structure and process.OLED is the abbreviation of organic light emitting diode, which is translated as organic light emitting diode or organic light emitting display. In fact, this luminescence principle was discovered as early as 1936, but it was not until Kodak launched OLED double-layer device in 1987 that OLED attracted people's attention as a commercializable and excellent flat panel display technology. At present, more than 100 research units and enterprises around the world have invested in the R & D and production of OLEDs, including display giants in the current market, such as Samsung, LG, Philips, Sony and so on. On the whole, the industrialization of OLED has begun, in which monochrome, multicolor and color devices have reached the level of mass production, and large-size full-color devices are still in the research and development stage, but the production capacity is still low.Many netizens are easy to associate OLED with the LED backlight hyped by current manufacturers. In fact, OLED and LED backlight are completely different display technologies. OLED emits light by driving the organic film itself through current. The light can be monochrome such as red, green, blue and white, and can also achieve full-color effect. Therefore, OLED is a new luminous principle different from CRT, led and liquid crystal technology.The LED display screen is composed of LED dot matrix and ledpc panel. The text, picture, animation and video can be displayed by turning on and off the red, blue, white and green LED lights. The content can be changed at any time. All components are display devices with modular structure. The traditional LED display screen is usually composed of display module, control system and power supply system. The display module is composed of a dot matrix composed of LED lamps, which is responsible for luminous display; By controlling the lighting of the corresponding area, the control system can make the screen display text, pictures, videos and other contents. Monochrome and two-color screens are mainly used to play text. The full-color LED display can not only play text, pictures, animation, but also play video and other formats.At present, it is widely used in every corner of the world because of its wide audience area, simple operation, long service life, energy conservation and environmental protection. In general, LED display, LED backlight and OLED are three completely different imaging technologies.
Common Faults and Troubleshooting of LED Display Screen
???...My Laptop Display Screen Needs Cleaning...???
Design and Implementation of LED Multifunctional Remote Control Display Screen
What Does the Laptop Screen Flash Mean
How Much Cost to Repair Itel Vision 1 Display Screen in India?
Apple May Release a New Screen Fingerprint Technology Patent in 2020
Corning Brings Gorilla NBT Glass to Touch Screen Laptop
Beginners Guide to Laptop Screen Replacement
How Does QFN Package Solve the Heat Dissipation Problem of LED Display Screen
related searches
What Is an OLED Display? This Article Teaches You to Understand the Difference Between LED Backlight
Common Faults and Troubleshooting of LED Display Screen
???...My Laptop Display Screen Needs Cleaning...???
Design and Implementation of LED Multifunctional Remote Control Display Screen
What Does the Laptop Screen Flash Mean
How Much Cost to Repair Itel Vision 1 Display Screen in India?
Apple May Release a New Screen Fingerprint Technology Patent in 2020
Corning Brings Gorilla NBT Glass to Touch Screen Laptop
Beginners Guide to Laptop Screen Replacement
Contact US

    Bao’an District  Shenzhen City, China

     +86 189 3806 5764

NEWSLETTER SUBSCRIBE
no data
Copyright © 2021 CrowBerry

   

chat online
NEED HELP? WE'RE HERE!