Master/slave

Definition

The master/slave architecture is a communication model used in industrial control systems, where one device, the master, controls one or more devices, the slaves. In this setup, the master sends commands to the slaves, which respond with data or perform tasks as directed. This relationship allows for organized communication and control within systems like PLCs, ensuring that data flows smoothly and efficiently.

5 Must Know Facts For Your Next Test

1. In master/slave configurations, the master device initiates all communication, reducing the chances of data collisions and ensuring orderly operation.
2. Master/slave architectures can be found in various industrial communication protocols, such as Modbus, CAN bus, and Profibus.
3. Slaves typically do not communicate with each other directly; they only respond to commands from the master.
4. This structure is highly effective for monitoring and controlling multiple devices from a single point of control.
5. The concept of master/slave has evolved in discussions about inclusivity and terminology in technology, prompting some to seek alternative terms.

Review Questions

• How does the master/slave architecture enhance communication efficiency in industrial control systems?
  • The master/slave architecture enhances communication efficiency by having the master device manage all interactions. Since the master initiates commands and requests data from the slaves, it prevents data collisions that can occur when multiple devices try to communicate simultaneously. This organized communication structure allows for precise control over multiple devices and ensures that data is relayed in a systematic manner.
• Compare the roles of master and slave devices in a typical PLC setup, highlighting their interactions.
  • In a typical PLC setup, the master device is responsible for sending commands to the slave devices, which are programmed to perform specific tasks or provide feedback. The master can poll slaves to gather status information or instruct them to execute certain operations. This interaction defines a clear hierarchical structure where the master maintains overall control while slaves focus on executing tasks or responding to queries.
• Evaluate the implications of using master/slave terminology in modern industrial communication protocols and consider alternative approaches.
  • Using master/slave terminology in modern industrial communication protocols can raise concerns about inclusivity and sensitivity in language. As discussions around these terms evolve, some industries are exploring alternatives like 'primary/secondary' or 'controller/device' to foster a more inclusive environment. This shift not only aims to avoid negative connotations but also encourages innovation in communication models that reflect contemporary values while still achieving effective control and monitoring.

Related terms

PLC (Programmable Logic Controller): An industrial digital computer designed for the control of manufacturing processes, such as assembly lines or machinery.

RTU (Remote Terminal Unit): A device used to remotely monitor and control equipment and processes, often functioning as a slave in master/slave configurations.

Bus Protocol: A communication protocol that defines how data is transmitted over a network, facilitating interaction between master and slave devices.