The technical breakdown analysis with common in use process PLC and safeguard

[editor's note] PLC is can make up Cheng controller one kind, there is certain application between many industries, dominate systematic life to lengthen PLC, the facility that pair of this systems want in be being used with production in systematic design is used up, yuan malfunction of equipment of parts of an apparatus produces a dot to have clearer estimation, that is to say, should know whole system what component gives trouble the most easily, so that take step. PLC is one kind can make up Cheng controller, there is certain application between many industries, dominate systematic life to lengthen PLC, the facility that pair of this systems want in be being used with production in systematic design is used up, yuan malfunction of equipment of parts of an apparatus produces a dot to have clearer estimation, that is to say, should know whole system what component gives trouble the most easily, so that take step. To breakdown of system of PLC process control distributinging rule undertakes an analysis, the system that hopes to be able to control a system to PLC process is designed and safeguard daily help somewhat. The notional system breakdown of systematic breakdown shows whole production controls the total of systematic invalidation commonly, it can be divided again control equipment malfunction for PLC breakdown and spot production two parts. PLC system includes O of ／ of box of central processor, lead plane, patulous box, I module and relevant network and peripheral equipment. Equipment of spot birth control includes port of I ／ O and spot control to detect equipment, wait like relay, contactor, valve, electromotor. The place of the most incidental breakdown is in system of lead plane of PLC of system of PLC lead plane commonly power source system and communication network system, power source is working continuously, medicinal powder absorption, the fluctuant concussion of voltage and electric current is inevitable. The possibility that communication and network suffer exterior interference is large, external environment is one of the biggest factors that cause trouble of communication peripheral equipment. The attaint of systematic bus line is main because PLC is plug-in unit structure more now, use for a long time insert unplug module can be caused local presswork board or the motherboard, bus line damage that receives the part such as plug-in unit interface, in air temperature the influence of change, humidity change falls, the plastic ageing of bus line, presswork the reason that the ageing of circuit, oxidation that contacts a dot is loss of systematic bus line. Be designed in the system so and processing system breakdown when should wait for the element destruction to equipment considering air, dust, ultraviolet ray. At present of PLC advocate memory is used mostly can brush write ROM, its service life besides basically close with photograph of the craft that make outside, return level of craft of module of the power supply with motherboard, CPU to concern. And the central processor of PLC uses high-powered processing chip at present, fault rate has dropped greatly. The precaution of the breakdown to system of PLC lead plane and processing basically are to raise concentration to control the level of management of the room, add outfit drop in temperature measure, remove dust regularly, make the external environment of PLC accords with his to install service requirement; It is at the same time when systematic maintenance, undertake strictly operating according to operating rules, beware the system causes pair of factitious main engine damage. The weak point with the biggest PLC of port of I ／ O of PLC is in port of I ／ O. The technical advantage of PLC depends on port of O of its I ／ , differ in the technical level of lead plane system very few below the circumstance, module of I ／ O is the crucial part that reflects PLC performance, accordingly it also is the outstanding link in PLC attaint. The breakdown that should reduce module of I ／ O is about to decrease exterior all sorts of interference are affected to its, the requirement that should use according to its above all undertakes use, cannot reduce its at will exterior protection equipment, analyse main interference factor next, to main interference the source should undertake keep apart or be handlinged. Spot control equipment is controlled in whole process site of the most incidental trouble is in in the system the spot, listed below a few gives trouble the most easily sides in the spot. 1) the first kind of breakdown is nodded (also be the place with most breakdown) in relay, contactor. In be being safeguarded what control a system like PLC of this product line daily, wastage of electric spare parts is the biggest for of all kinds relay or air switch. Main reason divides product itself outside, it is spot environment more abominable, contactor contact easy strike a light or oxidation, give out heat next till cannot be used,be out of shape. The control box of all on this product line spot is dish of ark with choose airtight sex better, its are in-house yuan of parts of an apparatus is otherer use open wide type dish inside ark yuan the service life of parts of an apparatus should grow apparently. Reduce this kind of breakdown to should choose high-powered relay as far as possible so, improve yuan of parts of an apparatus to use an environment, reduce changing frequency, in order to reduce the effect that its run to the system. 2) the 2nd kind of breakdown sends a dot to be in more valve or flashboard on this kind equipment, because the key of this kind of equipment carries out place, opposite displacement is general bigger, the position that perhaps should wait for the valve of ability of a few measure that finish or flashboard through electric changeover is changed, perhaps use the positional changeover of valve of dynamoelectric actuator push-pull or flashboard, each link such as mechanical, electric, hydraulic pressure does not have a bit reach the designated position to be able to produce error or breakdown. Use lack for a long time to safeguard, the main reason that barrier of hereat of mechanical, electric malfunction produces, because this wants to strengthen the check of make one's rounds to this kind of equipment when the system moves, discover the problem is handled in time. My factory built the rigid system that order check to this kind of equipment, often check valve to whether be out of shape, actuator is usable, controller is effective wait, assured the effectiveness of whole control system well. 3) on a few component that spot of the 3rd kind of trouble may produce on position of switch, maximum, safe protection and field work or equipment, because wear away for a long time,its reason may be, also may be long-term need not and rustily ageing. Like this product line kiln tails ball store the cloth on the library walks the car moves back and forth frequent, and spot dust is bigger, be close to switch contact to go out to be out of shape now so, oxidation, dust jams wait to bring about contact to contact thereby bad or orgnaization movement is not acute. Main to the processing of malfunction of this kind of equipment body is safeguarded regularly now, make equipment hour is in whole position. To spacing switch especially the spacing switch on heavy equipment besides scheduled maintenance, join multiple safeguard in the process of the design even. 4) spot of the 4th kind of trouble may happen in PLC system child equipment, be like the place such as nut of terminal of wiring box, line, bolt. The account that this kind of breakdown produces is returned besides the reason of the craft that make of equipment itself and install craft to concern, what if somebody thinks electrical wiring and bolt join are,press is closer better, but bring about very easily when be maintained 2 times it is difficult to disassemble, when disassembling energetically cause connection easily reach its the harm of around component. Long-term strike a light, rustily etc also is the cause that causes trouble. According to engineering experience, this kind of breakdown is very difficult discovery and maintenance commonly. The installation craft that must ask according to installation in the installation of equipment and maintenance so undertakes, do not take equipment hidden trouble. 5) spot of the 5th kind of trouble is sensor and appearance, what this kind of breakdown mirrors in signal commonly in controlling a system is abnormal. The screen layer of the line when this kind of equipment is installed should Chan Duanke relies on ground connection, lay apart with dynamical cable as far as possible, especially the transducer of senior officer faze outputs cable, and software filter wave should have in PIC interior. The discovery of this kind of breakdown and processing also are mixed check of daily feature make one's rounds is concerned, discover the problem should be handled in time. 6) the noise that the 6th kind of breakdown basically is power source, ground wire and line (disturb) , the settlement of the problem or improvement basically depend on the experience when the project is designed and the observation in be being safeguarded daily analysing. Want to reduce fault rate, very important is to should take plant technology and safe operating rules seriously, want to abide by craft and safe operating rules in day-to-day work, implement the provision of relevant management strictly, maintain concentration to control the environment of the room, at the same time aborning also should strengthen the management of these respects. CNC Milling