What Is a Microsequencer?
A microsequencer is a compact control device used for industrial equipment control and process control. It can perform various control tasks, such as digital signal processing, I/O control, and execution of control algorithms.
Microsequencers are characterized by their small size, ease of installation, and low cost.
In addition, combining multiple microsequencers may facilitate automatic control and remote control. By rewriting the program inside the control device, it is possible to supplement the role of another device.
Uses of Microsequencers
Microsequencers have a variety of uses as industrial devices. The following are typical applications:
1. Automation and Control Systems
Microsequencers are often used to control automated production lines and manufacturing processes. As an example, they are responsible for controlling each process on an assembly line in an automobile manufacturing plant. They are used in processes such as body welding, painting processes, and component installation. For each process, a microsequencer sends control signals to keep the production line operating efficiently and accurately.
They are also often used for product packaging, such as food and pharmaceutical packaging lines. Each process, such as label application and packaging material supply, is controlled for fast and accurate packaging.
2. Building Automation
Microsequencers are used to control lighting, air conditioning, and other equipment in office buildings. They can detect the presence of people and automatically control lighting, and monitor temperature and humidity for efficient energy use.
Similarly, they are also used to control smart homes. Not only can lighting and home appliances be remotely and automatically controlled, but services such as security system monitoring and alert functions can also be controlled. This provides a comfortable and safe living environment.
3. Energy Management
Microsequencers play a controlling and monitoring role in energy management systems, such as power plants and power supply networks. They can be used for power supply and distribution control, power quality management, and optimization of energy efficiency.
4. Traffic Control Systems
They are used in traffic control systems, such as traffic signal control and railroad signal control. They can reduce traffic accidents and facilitate traffic by regulating traffic flow and optimizing signal timing.
Principle of Microsequencers
Microsequencers are based on a control board that combines a CPU and peripheral circuits. The processing unit used is a specialized processor for digital signal processing and input/output control.
First, input data is acquired via sensors and external devices. Sensors used include temperature sensors and optical sensors. If the acquired data is analog data, it is converted to digital data inside the microsequencer using an analog-to-digital converter (ADC).
The control algorithm stored in the program’s memory is then executed. This algorithm is a program that performs control processing and calculations based on the input data to generate the appropriate output. The control algorithm is developed in a programming language and written to the microcontroller.
Based on this control algorithm, the appropriate output is generated. The outputs are sent as digital or analog signals to other devices. By repeating these series of operations, the device can be controlled.
How to Select a Microsequencer
There are several factors to consider when selecting a microsequencer. The following are the main selection factors:
1. Number of Inputs
This is the number of input signals that the microsequencer can process. You should evaluate the number of inputs required for your industrial process or control system and select a microsequencer with the appropriate number of inputs. In some cases, the number of inputs can be increased to several hundred by expansion.
2. Number of Output Points
The number of output signals that can be controlled by a microsequencer. Evaluate the number of output points required considering the number of devices and actuators to be controlled. It is often used to control solenoid contactors and solenoid valves.
3. Program Capacity
Microsequencers have program memory, which stores control algorithms and program code. When executing large control tasks or complex algorithms, it is necessary to select a microsequencer with sufficient program capacity. Depending on the product, this may be referred to as the number of steps, etc.
4. Communication Interface
This is an interface for communication with other systems or devices. Selecting a microsequencer with a communication interface compatible with industrial networks and protocols facilitates system integration and data collection and monitoring.
5. Power Supply
Microsequencers require a power supply. The type and voltage range of the power supply should be checked to select a microsequencer with a power supply suitable for the industrial environment. It is also important to consider features such as battery backup and redundant power supplies.