Honeywell HC900 manual Opc

Components and Architecture - Networking Basics Reference

Name/Acronym	Name/Definition	Comments
Node	Any intelligent device that	The “node” terminology is sometimes limited to
	includes a hardware address	computing devices such as PC hosts, but can also
	that can be recognized by	include networking devices such as Switches and
	other network devices.	Routers.
OPC	Object Linking and	OPC is an open standard that defines the exchange
	Embedding (OLE) for	of information between cooperating software
	Process Control	applications. OPC is based on the Distributed
		Common Object Model (DCOM) defined by
		Microsoft Corporation.
		OPC server and client software runs in computers
		interconnected on a network, and enables
		exchanges between process control devices and
		PCs configured as HMIs.
OSI Model	Open Systems	The OSI model is established by International
	Interconnection Reference	Standards Organization (ISO) to enable computer
	Model	communications using disparate media and
		protocols. Includes seven “Layers”; refer to "OSI
		Reference Model” for more information.
Packet	A bit sequence that is	The content of a packet varies with the protocols
	transmitted as an entity on a	that are applied. It includes the data message itself
	network.	and various routing and control information such as
		source and destination addresses.
		In many cases, a packet includes a set of frames for
		one protocol embedded (or encapsulated) in a set
		of frames for another protocol. (Several levels of
		encapsulation could be incorporated in a packet.)
Port	The physical connection on	For 10BaseT networking devices, ports are RJ-45
	a networking device.	connectors.
Port Multiplier	A “concentrator” (e.g., a	The Port Multiplier (a.k.a. Hub) forwards a
	Hub) is a multi-port device	message at any of its ports to all of its other ports,
	that enables one device to	with no isolation between the devices on these
	be connected to several	ports. Hence, a Hub constitutes a “collision
	others.	domain” for all connected devices.
PPP	Point-to-Point Protocol	Provides Router-to-Router and host-to-network
		connections over both synchronous and
		asynchronous circuits.
Print Server	A PC dedicated to printer	Services print requests from other nodes on the
	management.	network.
Protocol	A system of rules for
	communicating over a
	network.
Remote Access	Access to a network from a	Remote access usually uses a telephone line or the
	remote computer	Internet. The remote computer becomes a node on
		the accessed network by assuming control of a
		node actually on the network.
Repeater	Receives signals on an	A Repeater can extend the distance over which a
	incoming cable, reshapes	message can be transported, but it also expands the
	signal form and restores	time for transport.
	timing, then repeats the
	signal on an outgoing cable.

32	HC900 Hybrid Controller Installation and User Guide	Revision 5
		9/03