The working principles of common B&R modules

The working principles of common B&R modules 

Input/Output Modules:

• Digital Input Module: Digital signals from external devices such as switch signals and sensor status signals are input to the module. The internal circuit of the module processes and converts the input signals into a digital form that can be recognized by the control system and transmits them to the controller or other related modules through the communication interface. For example, when a photoelectric sensor detects an object passing by, it generates a high or low level signal. The digital input module converts this signal and transmits it to the control system so that the system knows the detection status of the object.

• Digital Output Module: When the control system issues a control command, the digital output module receives the command signal. The internal circuit of the module controls the on and off of the output circuit according to the command to output the corresponding digital signal to control the switching, starting and stopping actions of external devices. For instance, when the control system wants to start a motor, the digital output module will output a high-level signal to connect the starting circuit of the motor and start the motor.

• Analog Input Module: External analog signals such as continuous changing voltage signals output by temperature sensors and current signals output by pressure sensors enter the module through connection lines. The analog signal processing circuit inside the module amplifies, filters, and performs analog-to-digital conversion on the input analog signals to convert the analog signals into digital signals. Then, the digital signals are transmitted to the control system through the communication interface so that the control system can analyze and process the analog quantity.

• Analog Output Module: After the digital signal output by the control system enters the analog output module, the digital-to-analog conversion circuit inside the module converts the digital signal into an analog signal. The converted analog signal is output through the output interface to control devices that require analog signal input, such as frequency converters and proportional valves, thereby realizing continuous control of external devices. For example, when the control system wants to adjust the opening degree of an electric valve, it will output a corresponding current signal through the analog output module to the control mechanism of the valve to make the valve open to the specified opening degree.

Communication Modules:

• Fieldbus Communication Module: This module is responsible for realizing fieldbus communication between different devices in the automation system. It will encapsulate and encode the data to be sent according to the specifications of the supported fieldbus protocol (such as Profibus DP, Profinet, EtherCAT, etc.), making it conform to the format requirements of the protocol. Then, the data is sent to the bus through the physical connection line. At the same time, the module will receive the data sent by other devices on the bus and decode and decapsulate the data and transmit it to the local control system or related modules. In this way, different devices can exchange data and communicate through the fieldbus.

• Ethernet Communication Module: The Ethernet communication module works based on Ethernet communication protocols (such as Ethernet/IP, Modbus TCP, etc.). It converts the data from the control system or other modules into Ethernet packets and sends them to the network through the Ethernet interface. The module will also receive Ethernet packets from the network, parse them, and transmit the data to the local system or module. In this way, it realizes communication with upper computers and other Ethernet devices as well as remote monitoring and management functions.

Controller Modules:

• Programmable Logic Controller (PLC) Module: As the core control component of the automation system, the PLC module continuously executes the scanning program in a loop. First, the module samples the input signals and reads the status information of external devices obtained by the input module. Then, according to the control program written by the user, it performs logical operations and processing on the input signals, and performs judgment, calculation and other operations according to the logical relationships and algorithms set in the program. Finally, according to the processing results, it outputs control signals through the output module to control the operation of external devices. For example, in an automated production line, the PLC module controls the actions of a robotic arm according to the workpiece position and status information detected by sensors to realize the operations of grasping, transporting and placing workpieces.

• Industrial PC Module: The working principle of the industrial PC module is similar to that of an ordinary personal computer, but it is optimized in hardware and software to meet the requirements of the industrial environment. It uses the processor to calculate and process various data and runs the control software and monitoring software installed on it. These softwares can realize advanced control, management and monitoring of the production process, and at the same time provide a friendly human-machine interaction interface to facilitate operators to operate and monitor. The industrial PC module can communicate with other modules, obtain data from field devices, and analyze and process these data to make reasonable control decisions.

Motion Control Modules:

• Servo Drive Module: First, the module rectifies the input three-phase power or mains power through a three-phase full-bridge rectifier circuit to obtain the corresponding direct current. Then, the rectified direct current is frequency-converted by a three-phase sine PWM voltage source inverter to convert the direct current into three-phase alternating current with variable frequency and voltage to drive the three-phase permanent magnet synchronous AC servo motor. During the process of driving the motor, the module will monitor the running status of the motor in real time, such as speed, position, current, etc., and compare it with the set target value according to the feedback information. Through the control algorithm, the speed, position and torque of the motor are precisely controlled to achieve high-precision motion control.

• Stepper Motor Drive Module: The module controls the rotation of the stepper motor according to the pulse signal and direction signal issued by the control system. When a pulse signal is received, the module will drive the stepper motor to rotate a fixed angle (step angle). By controlling the frequency and number of pulse signals, the speed and rotation angle of the stepper motor can be controlled. At the same time, the module will also monitor and protect the running status of the stepper motor, such as overcurrent protection and overheating protection, to ensure the normal operation of the stepper motor.