Networking
STAR-BUS NETWORK
A star-bus network is a combination of a star network and a bus network. A hub (or concentrator) is used to connect the nodes to the network. It is a combination of the linear bus and star topologies and operates over one main communication line
STORAGE AREA NETWORK
In computing, a storage area network (SAN) is a network designed to attach computer storage devices such as disk array controllers and tape libraries to servers. As of 2006, SANs are common in enterprise storage.
There are two variations of SANs:
1. A network whose primary purpose is the transfer of data between computer systems and storage elements. A SAN consists of a communication infrastructure, which provides physical connections, and a management layer, which organizes the connections, storage elements, and computer systems so that data transfer is secure and robust. The term SAN is usually (but not necessarily) identified with block I/O services rather than file access services.
2. A storage system consisting of storage elements, storage devices, computer systems, and/or appliances, plus all control software, communicating over a network.
PROCESS CONTROL NETWORK
A Process Control Network (PCN) is a communications network that is used to transmit instructions and data between control and measurement units and Supervisory Control and Data Acquisition (SCADA) equipment.These networks have, over the years, used many of the technologies and topologies utilised in other network applications. However, Process Control Networks (PCNs)have several special requirements that must be met in order for the solution to be acceptable to the industry. These requirements are, in no particular order: Robustness, Determinacy, Compatibility. Robustness includes requirements such as connection redundancy, reduced sensitivity to Electromagnetic Interference (EMI), and good error checking and correction. Determinacy involves assuring that each device is guaranteed access to the network, and in many cases mechanisms to allow priority information (such as alarms) through the system. Compatibility allows SCADA and Distributed Control Systems (DCS) from various manufacturers to communicate with control and measurement equipment from others.
Many early PCN's were serial based, using low level standards such as EIA RS-422 and EIA RS-485 with proprietary protocols on top. One of the de facto standards (which is now becoming an open standard) is Modbus, originally from Modicon. Many PCN's used token ring token passing based protocols because they are essentially deterministic. Both Allen Bradley and Eurotherm utilised such mechanisms. Many of the measurement and control unit manufacturers signed up to the Fieldbus consortium but rather than one standard emerging each manufacturer promoted their own 'standard' leading to a myriad, and confusing, range of physical and logical systems.
VALUE-ADDED NETWORK
A value-added network (VAN) is a specialized application service provider (ASP) that acts as an intermediary between trading partners sharing data or business processes. VANs traditionally transmitted data formatted as Electronic Data Interchange (EDI) but increasingly they also transmit data formatted as XML. VANs usually service a given vertical or industry and provide value-added services such as data transformation between formats (EDI↔XML, EDI↔EDI, etc.). At one extreme a VAN hosts only horizontal business-to-business (B2B) application integration services, hosting general-purpose integration services for any process or industry
At the other extreme a VAN also hosts process-specific or industry-specific pre-defined integration capabilities (e.g., data synchronization services as part of the Global Data Synchronization Network (GDSN)) and applications (e.g., supply chain order visibility). Traditionally, most VANs primarily only supported general-purpose B2B integration capabilities focused on EDI but these service providers are quickly evolving to become more process- and industry-specific over time, particularly in industries such as retail and hi-tech manufacturing.
SOHO NETWORK
"SOHO network" is occasionally used to refer to a local area network as used a Small office/home office business.
The term is mainly useful to define a market segment which is has no internal IT staff, and possibly no dedicated server, structured cabling or server room, and where very high levels of performance and robustness are not warranted.
Compared to 19-inch rack based traditional business equipment, products designed for the SOHO market tend to be simpler, quieter, cheaper and "prettier".
The expression is falling out of use as these technologies become commonplace for personal home use.
STAR-BUS NETWORK
A star-bus network is a combination of a star network and a bus network. A hub (or concentrator) is used to connect the nodes to the network. It is a combination of the linear bus and star topologies and operates over one main communication line
STORAGE AREA NETWORK
In computing, a storage area network (SAN) is a network designed to attach computer storage devices such as disk array controllers and tape libraries to servers. As of 2006, SANs are common in enterprise storage.
There are two variations of SANs:
1. A network whose primary purpose is the transfer of data between computer systems and storage elements. A SAN consists of a communication infrastructure, which provides physical connections, and a management layer, which organizes the connections, storage elements, and computer systems so that data transfer is secure and robust. The term SAN is usually (but not necessarily) identified with block I/O services rather than file access services.
2. A storage system consisting of storage elements, storage devices, computer systems, and/or appliances, plus all control software, communicating over a network.
PROCESS CONTROL NETWORK
A Process Control Network (PCN) is a communications network that is used to transmit instructions and data between control and measurement units and Supervisory Control and Data Acquisition (SCADA) equipment.These networks have, over the years, used many of the technologies and topologies utilised in other network applications. However, Process Control Networks (PCNs)have several special requirements that must be met in order for the solution to be acceptable to the industry. These requirements are, in no particular order: Robustness, Determinacy, Compatibility. Robustness includes requirements such as connection redundancy, reduced sensitivity to Electromagnetic Interference (EMI), and good error checking and correction. Determinacy involves assuring that each device is guaranteed access to the network, and in many cases mechanisms to allow priority information (such as alarms) through the system. Compatibility allows SCADA and Distributed Control Systems (DCS) from various manufacturers to communicate with control and measurement equipment from others.
Many early PCN's were serial based, using low level standards such as EIA RS-422 and EIA RS-485 with proprietary protocols on top. One of the de facto standards (which is now becoming an open standard) is Modbus, originally from Modicon. Many PCN's used token ring token passing based protocols because they are essentially deterministic. Both Allen Bradley and Eurotherm utilised such mechanisms. Many of the measurement and control unit manufacturers signed up to the Fieldbus consortium but rather than one standard emerging each manufacturer promoted their own 'standard' leading to a myriad, and confusing, range of physical and logical systems.
VALUE-ADDED NETWORK
A value-added network (VAN) is a specialized application service provider (ASP) that acts as an intermediary between trading partners sharing data or business processes. VANs traditionally transmitted data formatted as Electronic Data Interchange (EDI) but increasingly they also transmit data formatted as XML. VANs usually service a given vertical or industry and provide value-added services such as data transformation between formats (EDI↔XML, EDI↔EDI, etc.). At one extreme a VAN hosts only horizontal business-to-business (B2B) application integration services, hosting general-purpose integration services for any process or industry
At the other extreme a VAN also hosts process-specific or industry-specific pre-defined integration capabilities (e.g., data synchronization services as part of the Global Data Synchronization Network (GDSN)) and applications (e.g., supply chain order visibility). Traditionally, most VANs primarily only supported general-purpose B2B integration capabilities focused on EDI but these service providers are quickly evolving to become more process- and industry-specific over time, particularly in industries such as retail and hi-tech manufacturing.
SOHO NETWORK
"SOHO network" is occasionally used to refer to a local area network as used a Small office/home office business.
The term is mainly useful to define a market segment which is has no internal IT staff, and possibly no dedicated server, structured cabling or server room, and where very high levels of performance and robustness are not warranted.
Compared to 19-inch rack based traditional business equipment, products designed for the SOHO market tend to be simpler, quieter, cheaper and "prettier".
The expression is falling out of use as these technologies become commonplace for personal home use.
