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Memory-mapped I/O is preferred in IA-32 and x86-64 based architectures because the instructions that perform port-based I/O are limited to one register: EAX, AX, and AL are the only registers that data can be moved into or out of, and either a byte-sized immediate value in the instruction or a value in register DX determines which port is the source or destination port of the transfer.
In computer networking, a port or port number is a number assigned to uniquely identify a connection endpoint and to direct data to a specific service. At the software level, within an operating system , a port is a logical construct that identifies a specific process or a type of network service .
An ephemeral port is a communications endpoint of a transport layer protocol of the Internet protocol suite that is used for only a short period of time for the duration of a communication session. Such short-lived ports are allocated automatically within a predefined range of port numbers by the IP stack software of a computer operating system.
A grid computing system that connects many personal computers over the Internet via inter-process network communication. In computer science, interprocess communication (IPC) is the sharing of data between running processes in a computer system. Mechanisms for IPC may be provided by an operating system.
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. Modern process control networks rely on Ethernet, TCP/IP, and Microsoft Windows technology. [1]
A male D-subminiature DE-9 connector on an IBM PC compatible computer (with serial port symbol) used for an RS-232 serial port A female D-subminiature DE-9 connector on an RS-232 cable. A serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. [1]
OPC specifies the communication of real-time plant data between control devices from different manufacturers. After the initial release in 1996, the OPC Foundation was created to maintain the standards. [1] Since OPC has been adopted beyond the field of process control, the OPC Foundation changed its name to Open Platform Communications in 2011 ...
The send function serves the same purpose as the trap; that is, it carefully checks the message, switches the processor to kernel mode, and then delivers the message to a process that implements the target functions. Meanwhile, the user process waits for the result of the service request with a message receive operation.