Tag: Industrial networking
-
Fundamental Communication & Networking Terminology
To be able to choose the right network technology, it is essential to understand some key terminology so that the features and capabilities of various networks and technologies can be categorized and compared. Some of the basic communication and networking terminology includes: Station A station represents a single communication element on a network system. Each…
-
The IEEE-488 Instrumentation Bus (GPIB)
A bus in computer systems means a collection of unbroken signal lines that interconnect computer modules; these connections are usually made by taps on the lines. Examples of parallel bus architectures and protocols include: IBM PC bus (IBM PC/XT/AT), the Intel iSBX bus, the MicroVAX Q-bus, the Intel Multibus (IEEE-796 bus), the IEEE-488 instrumentation bus…
-
Key Facts about RS-485 Industrial Network
RS-485 network is used in many industrial applications to gather data and control addressable motor drives, PLCs, cameras, time clocks, barcode scanners for process control and other factory automatic apparatus. RS-485 devices can be connected to a computer and multi-dropped at various locations in a network style configuration. The devices can be up to 4000…
-
Open Systems Interconnection Communication (OSI) Model
Developed by the ISO (International Organization for Standards) in 1983, the Open Systems Interconnection (OSI) reference model divides communication functions into seven-layer standard protocol system. The OSI model is a framework for developing a coordinated system of standards. The seven layers are described as follows: 1 Physical Layer This layer describes the means for bit…
-
ZigBee Wireless Protocol for Industrial Communication
ZigBee is an open wireless standard for low-rate networks. It is an IEEE standard 802.15.4 protocol. The physical layer radio operates at 2.4 GHz band carrier frequencies with direct sequence spread spectrum (DSSS). It supports a range of up to 70 m. Data transfer rate supported is 250 kbps. It supports sixteen channels. A ZigBee…
-
How Modbus is used in Industrial Networks
Modbus is an open standardized communication protocol that was founded by Modicon. Initially it was designed for the communication among PLCs in industrial applications but it also gained significance use in building automation domain for instance in HVAC systems, DDCs and room control. In a nutshell, Modbus is an application layer messaging, protocol placed at…
-
Network Access Control Techniques
Access control methods are required in a network to ensure that only one user of the network is able to transmit at any one time. In ring-based local area networks (LANs), two commonly employed techniques are: Token Passing In this technique, a token i.e. a special bit pattern, is circulated. When a station wishes to…
-
Features of a Serial Interface
In a serial interface, the data is sent 1 bit after the other on a single wire. Serial data is classified as being either synchronous or asynchronous. Synchronous data require that the data bytes be sent as group in a “package”. It is employed in advanced communication systems that move a lot of data. Asynchronous…
-
Basic Features of Sercos Automation Bus
Sercos is a short form for serial real-time communication system; a digital automation bus that interconnects motion controls, drives, I/O, sensors, and auxiliary devices such as cameras and weighing stations. Sercos is an open controller-to-intelligent digital device interface, designed for high-speed serial communication of standardized closed loop data in real time (RT). Sercos I and…
-
Advantages of Industrial Control Networks
Industrial networks have evolved to become an integral part of manufacturing replacing the point-to-point communication at all levels. At lower levels in the plant/factory setup, networks provide higher reliability, visibility and diagnosability and enable capabilities such as distributed control, diagnostics, safety and device interoperability. At higher levels networks can leverage internet services to enable factory-wide…