Preeflow controller, German Preeflow model, Preeflow price

The Preeflow controller uses a chip to control switches at various positions in the LED lamp circuit. There are two types of controllers with different structures due to different design methods. A micro-operation is an operation that cannot be further decomposed; performing a micro-operation always requires a corresponding control signal (called a micro-operation control signal or micro-operation command). A digital computer can basically be divided into two parts: the control unit and the execution unit. The controller is the control unit, while the arithmetic logic unit, memory, and peripheral devices are the execution units relative to the controller. One connection between the control unit and the execution unit is through control lines. The control unit sends various control commands to the execution unit via control lines; these control commands are usually called micro-commands, and the operations performed by the execution unit after receiving the micro-commands are called micro-operations. Another connection between the control unit and the execution unit is feedback information. The execution unit reflects the operation status to the control unit via feedback lines, so that the control unit can issue new micro-commands based on the state of the execution unit; this is also called "status testing". Micro-operations are basic operations within the execution unit.

Preeflow controller classification

1) Non-networked door controller: a single unit manages one door. It cannot be controlled by computer software, nor can records be viewed; control is performed directly through the controller. Features include low price and simple installation and maintenance. However, records cannot be viewed. It is not suitable for locations with more than 50 people or where personnel turnover is frequent (referring to frequent hiring and resignations), nor is it suitable for projects with more than 5 doors. 2) Networked door controller: an access control type that can communicate with a computer, allowing direct management via software, including card and event control. Benefits include convenient management, centralized control, record viewing, and analysis of records for other purposes. Features include higher price and increased difficulty in installation and maintenance, but training is simple, and value-added services such as attendance tracking are available. Suitable for projects with many people, high turnover, and many doors. 3) TCP/IP network door controller: also known as Ethernet networked access control, this is a networkable access control system that connects the computer and controller via network cables. In addition to all the advantages of networked access control, it offers faster speed, simpler installation, greater networking capacity, and the ability to network across regions or cities. However, equipment costs are high, and computer networking knowledge is required. Suitable for large projects, locations with many people, applications requiring high speed, and cross-regional projects.

Preeflow controller structure

Instruction Register: A register used to hold the instruction currently being executed or about to be executed. The instruction contains an opcode that determines the operation type and an address that indicates the source or destination of the operand. Instruction length varies among different computers, and the length of the instruction register varies accordingly. All computer operations are performed after analyzing the instructions stored in the instruction register. The input end of the instruction register receives instructions from memory. The output end of the instruction register is divided into two parts. The opcode part is sent to the decoding circuit for analysis to determine what type of operation the instruction should perform; the address part is sent to the address adder to generate the effective address, which is then sent to memory as the address for fetching or storing data. Memory can refer to main memory, cache, or register stacks used to hold the instruction currently being executed. When executing an instruction, it is first fetched from memory into the data register (DR), and then transferred to IR. Instructions are divided into opcode and address fields, composed of binary digits. To execute any given instruction, the opcode must be tested to identify the required operation. The instruction decoder performs this task. The output of the opcode field in the instruction register is the input to the instruction decoder. Once the opcode is decoded, it sends specific signals for the specific operation to the operation controller. Program Counter: A counter that specifies the address of the next instruction to be executed in the program, also known as the instruction counter. It combines the functions of an instruction address register and a counter. When an instruction is finished executing, the program counter, acting as the instruction address register, must have its content changed to the address of the next instruction, allowing the program to continue running.

Preeflow controller wiring

1) DC 24 V terminal block: The 24 V terminal block on the PLC can also supply current to external sensors (such as proximity switches or photoelectric switches). When the 24 V terminal is used as the sensor power supply, the COM terminal is the DC 24 V ground. If an expansion unit is used, the 24 V terminals of the basic unit and the expansion unit should be connected. Additionally, no external power source should be connected to this terminal. If an overload occurs, the voltage will drop automatically, and the input at this point will not affect the programmable controller. The number of input points for each model of PLC is specified. Each unused input point does not consume power, so in this case, the current supply capability of the 24 V power terminal can be increased. 2) Input wiring: Generally accepts discrete signals from inputs such as limit switches and travel switches. The input terminal block is the port for signal conversion between the PLC and external sensor loads. Input wiring generally refers to the wiring between external sensors and input ports. Input devices can be any passive contacts or collector-open NPN transistors. When the input device is activated, the input terminal is connected, the input circuit is closed, and the input indicator LED lights up. Galvanic isolation via optocouplers is used between the primary and secondary circuits of the input terminal. The secondary circuit includes an RC filter to prevent malfunction of the PLC caused by contact bounce or electrical noise coupled from the input lines. If a diode is connected in series in the input contact circuit, the voltage across the series diode should be less than 4 V. If a reed switch with an LED is used, the number of series diodes must not exceed two.

Weidou Intelligent Technology specializes in selling German Preeflow servo drives, Preeflow servo amplifiers, Preeflow programmable controllers, Preeflow control units, Preeflow industrial PCs, Preeflow logic controllers, Preeflow drum controllers, Preeflow relay controllers, Preeflow control systems, Preeflow motion controllers, Preeflow microcontrollers, Preeflow control modules, Preeflow control switches, Preeflow servo controllers, and Preeflow expansion modules. Preeflow products are original imports from Germany. Customers are welcome to inquire and order.