In this guide, we will explore how to achieve forward and reverse control of a stepper motor using a PLC (Programmable Logic Controller) and HMI (Human-Machine Interface). Below are the setup and programming steps required for precise control.
A programmable logic controller (PLC) is a digital arithmetic operation electronic system specially designed for application in an industrial environment. It uses a programmable memory in which the instructions for performing operations such as logical operations, sequence control, timing, counting and arithmetic operations are stored, and various types of mechanical equipment or production processes are controlled through digital or analog input and output. ATO online store offers you Delta's DVP series programmable logic controllers with high speed, stability and reliability, applicable for various industrial automation machines.
ATO HMI touch screen can be connected to industrial control equipment such as programmable logic controller, inverter, DC speed regulator and instrument. Its display shows that the digital device that realizes the interaction of human and machine information through input unit to write working parameters or input operation commands. Now let’s program and test the HMI and PLC.
Human machine interface refers to the field where people and machines contact or interact with each other in information exchange and function. This joint surface includes not only the direct contact between point, line and surface, but also the action space of long-distance information transmission and control. So how does HMI communicate with PLC?
A load cell is a force transducer. It converts a force such as tension, compression, pressure, or torque into an electrical signal that can be measured and standardized. As the force applied to the load cell increases, the electrical signal changes proportionally. The most common types of load cell used are strain gauges, pneumatic, and hydraulic.
A photoelectric sensor is a device that converts optical signals into electrical signals. Its working principle is based on the photoelectric effect. The photoelectric effect refers to the phenomenon of the corresponding electrical effect occurring when the electrons of the material absorb the energy of photons when light is irradiated on certain substances. Photoelectric switch is generally used for automation equipment. This blog mainly introduces how does a PLC control photoelectric sensor?
Generally, using PLC as an intermediate tool for HMI to control VFD is a good choice. Now, let’s us establish and HMI to control the VFD project. We need to communicate with an Omron PLC and use the PLC commands to control the VFD. Set the PLC model and communication parameters (RS232, Host Link communication protocol) that need to be communicated.
A programmable logic controller (PLC) or programmable controller is an industrial computer that has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, machines, robotic devices, or any activity that requires high reliability, ease of programming, and process fault diagnosis. A variable-frequency drive (VFD) is a type of motor drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and, depending on topology, to control associated voltage or current variation.
A programmable logic controller (PLC) or programmable controller is an industrial computer that has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, machines, robotic devices, or any activity that requires high reliability, ease of programming, and process fault diagnosis. PLCs were first developed in the automobile manufacturing industry to provide flexible, rugged and easily programmable controllers to replace hard-wired relay logic systems. In this article, we will introduce the counter function of PLC.
The PLC program interlocks the forward and reverses the rotation of the motor to prevent the wrong touch of the motor's reverse rotation button. PLC and the VFD are powered on for 2s time control. After the motor stops, it needs to wait for 10s before the motor can be restarted. This is very practical in practical applications (there is a good buffer process for motor inertial motion).
ATO relay module adopts high-current relay (1NO+1NC or 2NO+2NC), available with 2 to 32 channel, LED indicator for working status, standard DIN rail mounting, widely used for all MCU control, industrial automation, PLC control, smart home control. This blog shows that how does PLC control relay module.
Speed control is generally achieved by inverters, servo motors to do speed control, is generally used for rapid acceleration and deceleration or speed precision control occasions, because relative to the inverter, servo motors can reach thousands of revolutions within a few millimeters, because the servo is closed-loop, the speed is very stable. Torque control is mainly to control the output torque of the servo motor, again because of the fast response of the servo motor. Application of the above two kinds of control, you can treat the servo drive as a frequency converter, generally with analog control.
Programmable Logic Controller referred to as PC or PLC is an electronic system operated by digital operations, specially designed for application in an industrial environment. It uses a memory that can be programmed to execute instructions for storing logical operations and sequence control, timing, counting and arithmetic operations, and through digital or analog input (I) and output (O) interfaces, controls various Type of mechanical equipment or production process. PLC is developed on the basis of electrical control technology and computer technology, and gradually developed into a new type of industrial control device with microprocessor as the core and integrating automation technology, computer technology and communication technology. PLC has been widely used in the automatic control of various production machinery and production processes.
Programmable Logic Controller, short for PLC, is a digital electronic device with a microprocessor. The device is a digital logic controller for automatic control, which can load control instructions into the memory at any time for storage and execution. The programmable controller is composed of internal CPU, instruction and data memory, input and output units, power supply modules, digital and analog units.
When the PLC is put into operation, its working process is generally divided into three stages, namely input sampling, user program execution and output refresh three stages. Completing the above three stages can be called a scan cycle. During the entire operation, the CPU of PLC repeatedly executes the above three stages at a certain scanning speed.
In PLC control system, we mostly use DC proximity sensors. And in DC circuit, the proximity sensors used include 2-wire proximity sensor, 3-wire proximity sensor and 4-wire proximity sensor. And they can be further divided into NPN type and PNP type. Generally, people in the United States and Japan usually use NPN proximity sensor, while in the Europe use the PNP proximity sensor.
The difference of NPN proximity sensor and PNP proximity sensor lies in the conduction situation. NPN proximity sensor belongs to the low level conduction and PNP proximity sensor belongs to the high level conduction. In other words, signal of the NPN proximity sensor flows from the load to the proximity sensor, while that of the PNP proximity sensor flows from the proximity sensor to the load.
We will take FX3U PLC and S7-200 PLC as examples to explain how is the NPN proximity sensor and PNP proximity sensor connected to PLC.
In our load cell product pages, when we introducing the load cells, we often say that you can buy a transmitter/amplifier with a customized output signal (0-5V, 0-10V, 4-20mA) to output standard signal to PLC, DCS and other control systems. Then someone will ask us how to connect load cell to plc. Now today we will explain the connection methods of load cell in details. When forming the weighing and batching control system with PLC, there are four connection methods for load cell.
