Megmeet PLC - What are the five stages of the PLC work process?

1. Correctness (low debugging cost) First of all, the PLC program must be able to work correctly to meet the requirements of the actual control process. This is the essence of the PLC program, and if you don't do that, nothing else makes sense. 2. Reliability (low maintenance cost) Not only to ...

1. The meaning of the representation is different: PLC is the abbreviation of planar optical waveguide (technology), the so-called planar optical waveguide, means that the optical waveguide is located in a plane. A servo control system is a feedback control system used to accurately follow or reproduce a certain process.

1) Hand arc welding (STICK) Shielded Arc Welding (abbreviated SMAW) in English, The principle is: the welding method of generating an electric arc between the coating electrode and the base metal, and using the arc heat to melt the electrode and the base metal. The outer layer of the electrode is covered with solder, and it melts when heated.

Fault one Fault phenomenon: the leakage protection switch trips, the inverter is energized or the equipment leakage protection switch is operated during operation Solution: 1. When the inverter drives the motor, the leakage value is larger than that of the non-inverter system, and the leakage protection value of the leakage protection switch is required to be more than 150mA, ...

(1) Spot welding: The weldment is pressed between the two cylindrical electrodes, heated by electricity, so that the weldment melts at the contact to form a nugget, and then the power is cut off, and it solidifies and crystallizes under pressure to form a dense solder joint. Spot welding is suitable for welding thin plates (laps) and steel bars below 4 mm.

(1) In terms of control method: PLC adopts a program to achieve control, which is easy to change or increase the control requirements, and the contact points of PLC are unlimited; (2) In terms of working mode: PLC adopts serial working mode to improve the anti-interference ability of the system; (3) Control speed: PLC ...

1. Grounding problems The grounding requirements of the PLC system are relatively strict, and it is best to have an independent dedicated grounding system, and it should also be noted that other equipment related to PLC should also be reliably grounded. When multiple circuit grounding points are connected together, unexpected currents can be generated, resulting in logic errors or ...

1. The welding machine has no welding current output 1. Cause of failure: the internal wiring of the non-voltage input at the input end of the welding machine falls off or the internal coil of the broken circuit is burned out. 2. Treatment method: check whether the switch, wire, fuse and connection parts from the distribution box to the input end of the welding machine are in good condition.

1. Check the circuit according to the drawing (without power transmission) The drawings of the general PLC system include two parts: the drawings in the cabinet and the drawings outside the cabinet; The drawing in the cabinet refers to the wiring diagram inside the cabinet; The out-of-cabinet drawings are the wiring diagrams of all electrical cabinets. This part needs to be checked for; ...

Open-loop control Open-loop control of switching quantity is the most basic control function of PLC. The instruction system of PLC has powerful logic operation ability, and it is easy to realize various logic control methods such as timing, counting, and sequential (stepping). Most PLCs are used to replace traditional relay contactors...

First, the disadvantages Choosing too high a voltage level results in too high an investment and a long payback period. With the increase of the voltage level, the insulation of the motor must be improved, so that the price of the motor increases. The increase of voltage level increases the number of series connections of power semiconductor devices in the inverter, and the cost rises. ...

1. Overcurrent fault of inverter Fault Code: OCF. (1) Fault name: inverter overcurrent fault (2) The cause of the failure: the motor nameplate data input is incorrect: the load dragged by the motor is too heavy: the machinery is stuck; Motor stalled. （3） ...

1. The electrical control cabinet installed with PLC should have a clean and dry environment. Moisture-absorbing dry materials should be placed inside, and the splashing of coolant and oil mist should be prevented. 2. Regardless of the system working or shutdown, the electrical cabinet door should always be closed, and the electrical components should be kept in a good state.

1. Leakage protection switch Phenomenon: The leakage protection switch of the equipment is activated when the inverter is powered on or running Measures: When the inverter drives the motor, the leakage value is larger than that of the non-inverter system, and the leakage protection value of the leakage protection switch is required to be 150mA and above, and the action delay is ...

1. Application field: The initial design goal of PLC is only to replace complex relay circuits, and DDC is originally only used in industrial automation instruments: PLC emphasizes versatility, DDC emphasizes specificity: PLC is used in the field of industrial control, and DDC is used in professional building systems. 2. Structural differences ...

The first is that the PLC sends a start/stop signal to the server through the I/O point, and the server controls the operation of the servo motor. The PLC controls the operation/stop of the servo through the digital output, so as to achieve the purpose of controlling the servo motor. The second is through the pulse output of the PLC, which ...

(1) Select components and materials with good heat resistance and thermal stability to increase their allowable working temperature; (2) Reduce the heat generated inside the equipment (device). To this end, micropower devices, such as low-loss IGBTs, should be used more often, and the number of heat-generating components should be minimized in the circuit design.

1. The operating ambient temperature of the inverter (mainly refers to the air temperature of the air inlet of the power unit cabinet) requires a minimum ambient temperature of -5 °C and a maximum ambient temperature of 40 °C. In order to improve the reliability and extend the service life of the drive, check the following items: Air conditioning and refrigeration ...

1. Understand the type of variable frequency load The correct selection of the frequency converter is very critical for the proper operation of the control system. When selecting a frequency converter, it is important to fully understand the load characteristics driven by the frequency converter. In practice, production machinery is often divided into three types: constant torque load, constant ...

1. Hydraulic coupling method. That is, a hydraulic coupling device is inserted between the motor and the load in series, and the size of the coupling force between the motor and the load is adjusted by the height of the liquid level, so as to realize the speed adjustment of the load; 2. Cascade speed regulation. Tandem speed regulation must use a wound asynchronous motor, and the rotor ...