plc program
Using two or more normally closed contacts to ensure the coil does not power on function "interlock". Pros and cons of three-phase asynchronous motor control circuit for a typical interlock circuit, as shown in Figure 5-4. KMl and KM2 of which is to control the forward run and reverse operation of AC contactors.Figure 5-4 the … Continue reading Interlocking functions of PLC program of ladder diagram
Its normally open coils continue to stay in power "ON" State function is called locking. As shown in Figure 5-3 the start, maintain and stop the program (stop program for short) is a typical ladder with locking function, X2 and X1 as the starting signal for the stop signal.Figure 5-3 from the stop procedure and … Continue reading Self locking function of PLC ladder diagram
Ladder diagram relay diagram in the structure, element symbols and logic control functions are similar, but they also have many differences, ladder diagram programming has its own rules.1) each logical line always begins with a bus left, then contact connection, finally ending in the coil or the right bus (bus could not draw on the … Continue reading Rules of PLC ladder diagram programming
1. Overview of FX-2DAFX-2DA analog output module FX series specific analog output module. Converts the numeric value of this module, 12-bit analog output accordingly. FX-2DA channel 2 output through the output terminal transforms can also choose any voltage or current output state. When the output voltage, output signals in the range of ~+10V, can be … Continue reading FX-2DA PLC analog output module
FX2N series in the analog special function module: FX2N-2AD (2 channel analog input), FX2N-4AD (4-channel analog input), the FX2N-8AD (8 channel analog input), FX2N-4AD-PT (4 channel RTD input directly), FX2N-4AD-TC (4-channel thermocouple direct input), FX2N-2DA (2 channel analog output), FX2N-4DA (4-channel analog output) and FX2N-2LC (2-way temperature PID control module).Following introduces common analog input module … Continue reading FX-4AD PLC analog input module
Traditional analog control system using electric instrument, common DDZ-and DDZ-type ⅱ-ⅲ instrument. The characteristics of simple structure, low price, great size, great power, installation complexity, generality and flexibility, accuracy and stability. In addition, its control functions are simple, complex process control cannot be achieved. With the development of technology and new process control computers emerging … Continue reading PLC compared with other analog devices
PLC I/O wiring diagrams, selection of FX2N-48MR PLC, there are 18 input devices output device and 5 respectively, occupy 18 inputs of the PLC output and 5 points, invites the reader to consider whether the fourth section of this chapter describes the method can be used to reduce the amount of PLC I/O points. In … Continue reading FX2N-48MR PLC I/O distribution
PLC in practical applications often run into two problems: one is the PLC I/O points is not enough and needs to be expanded, however increased I/O points will increase costs; second, the PLC has selected an Extensible I/O points are limited and cannot be increased. Therefore, on the premise of meet the system requirements, the … Continue reading How to reduce PLC outputs
PLC in practical applications often run into two problems: one is the PLC I/O points is not enough and needs to be expanded, however increased I/O points will increase costs; second, the PLC has selected an Extensible I/O points are limited and cannot be increased. Therefore, on the premise of meet the system requirements, the … Continue reading How to reduce PLC input points
Linear programming Division of programming and structured programming (industrial mixing system).Objects that are mixing requirements are as follows:1. When component a (b) pump when required: 1) components of a (b) inlet valve has been opened, discharging valve is open; 2) mixing bucket is not full, the mixing valve closed; 3) the pump drive motor failure, … Continue reading Structure design of PLC control system
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