Protocol, communication

A recent data communications protocol for Building Automation and Control Networks (BACnet), ASHRAE Standard 135-1995, is an important step to ensure that controllers made by different manufacturers can communicate with each other in a simple way, avoiding the expense of additional interface hardware and communication software. 

Data transfer The data acquisition unit will not be used for long-term data storage. Therefore, it must be able to reliability transfer data into the host computer. The actual time required to transfer the microprocessor s data into the host computer is the only non-productive time of the data acquisition unit. It cannot be used for acquiring additional data during the data transfer operation. Therefore, the transfer time should be kept to a minimum. Most of the available systems use an RS 232 communications protocol that will allow data transfer at rates of up to 19,200 baud. The time required to dump the full memory of a typical microprocessor can be 30 minutes or more. 

The microprocessor should also be able to support modem communication with remote computers. This feature will enable multiple plant operation and direct access to third party diagnostic and analysis support. Data can be transferred anywhere in the world using this technique. Not all predictive maintenance systems use a true RS 232 communications protocol or support modem communications. These systems can severely limit the capabilities of your program. The various predictive maintenance techniques will add other specifications for an acceptable data acquisition unit. 

Within a software design, the different levels of refinement are generally associated with different, decoupled layers in the software. We can see this, for example, in the conventional separation into business and GUI layers. We can also see it in communications protocols, from the individual bits up through to the secure movement of files and Web pages. 

Horizontal slices This technique separates business models, specifications, and designs down to the level of technical infrastructure and communication protocols. These are different levels of description of the same phenomenon and are related primarily by some form of refinement relation. 

Check that all communications protocols are being used as intended. 

Ensure all employees are aware of communications protocols with relevant law enforcement, public health, environmental protection, and emergency response organizations. 

Implementing this level of automation intelligence has been the most difficult to realize within manufacturing industries. That is, while automation controls integration of simple univariate instruments (e.g., a hlter photometer) is seamless, it is much more problematic for multivariate or spectral instruments. This is due to the tower of babble problem with various process spectroscopic instraments across process instrument manufactures. That is, the communications protocols, wavelength units and hie formats are far from standardized across spectral instruments, even within a particular class of techniques such as vibrational spectroscopy. Several information technology (IT) and automation companies have recently attempted to develop commercialized solutions to address this complex problem, but the effectiveness of these solutions has yet to be determined and reported. 

System installation in a permanent location may require a sample conditioning system featuring some degree of automation, such as automatic cleaning (the system illustrated above features such a system) and outlier sample collection and the need to interface to an existing control system process computer. The latter may require that the system operates with a standardized communications protocol, such as Modbus, for the chemical industry. Certain specialized industries use different protocols, such as the semiconductor industry, which uses SECS and SEC-11 protocols. A standardized approach designated the Universal Fieldbus is another method/protocol for process analyzers which is being supported by certain hardware manufacturers. 

Entanglement is the main resource of quantum information processing, without which quantum computation will not be faster than its classical counterpart [8] and quantum communication protocols will not work [113-115]. Moreover, as shown... 

Packets are data structures consisting of storage areas called fields and can either be formatted or unformatted. Formatted packets have fields designed according to a packet format which specifies the packets field names, data types, sizes, and default values. Formatted packets can be read by corresponding communication protocols only. Unformatted packets have no predefined fields. In IT-Guru, packet formats are predefined and typically named according to the model in which they are intended to be used. 

Operating system software—document version and data communication protocols, and establish extent of use. 

The recent introduction of standardized communication protocols has led to a decrease in capital cost. Most current DCS network protocol designs are based on the ISO-OSI seven-layer model with physical, data link, network, transport, session, presentation, and application layers. 

Telnet. Telnet is a program using the communication protocol of the Internet (TCP/IP) to provide a connection onto remote computers. You can use Telnet to contact a host machine simply by typing in the host name or IP number if you have Internet access from your computer. You will then be asked for a login identity and your password. Often buried within Telnet is a version of FTP, so you can transfer files from the TCP/IP host to your own computer. 

Positioning systems can use a network communication configuration, where the components operate as nodes on a network. Network communications protocols include ARCnet, CANbus, DeviceNet (a version of CANbus), Ethernet, PROFIBUS, IEEE 1394 (FireWire), IEEE 1451, Interbus-S, SERCOS, and Seriplex, among others. PC bus-type protocols include the normal backplane ISA/EISA (PC-XT/AT) connection for a PC, MAC PCI (Nubus) for Macintosh computers, Multibus, PC 104, PCI bus, cPCI bus (compact PCI), PCMCIA, VME bus, and VXI. 

Interfaces in the control loop must be standardised. Different suppliers normally have proprietary control systems, thus it is vital to select a standard communication protocol in the early design phase, preferably based on industry standards. 

The high-performance, all-digital, multidrop communication protocol for use in the process-control industry is known as fieldbus. Presently there are several regional and industry-based fieldbus standards including the French standard, FIP (NFC 4660x approved by UTE), the German standard, Profibus (DIN 19245 approved by DKE), and proprietary standards by DCS vendors. As of 1997, none of these fieldbus standards have been adopted by international standards organizations. 

Diagnostic checks are normally conducted as a part of the IQ. Such checks include those of the built-in system configuration, conducting system loading tests, and checking timer accuracy. Software drivers, such as communication protocols, will also require testing. 

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