GE 90*-30 PLC Series User Manual

Also see for 90-30 PLC: Installation and Hardware Manual

Contents

GFK-1322 Appendix D Glossary D-5DEthernet Interface The general term used in this manual to identify the GEnet hardwaremodule, with or without software, that connects a PLC (or CNC) to anetwork. It may also appear in the shortened form, “Interface”. (Seealso LAN Interface.)Flash Memory A type of read-only memory that can be erased and reprogrammedunder local software control. It is used to store data that must bepreserved when power is off..Frame A data structure that consists of fields, predetermined by a protocol,for the transmission of user data and control data.Gateway A special purpose, dedicated computer that attaches to two or morenetworks and routes packets from one to the other. In particular, anInternet gateway routes IP datagrams among the networks to which itconnects. Gateways route packets to other gateways until they can bedelivered to the final destination directly across the physical network.(Also sometimes referred to as a router.)Global Address Administration Address administration in which all LAN individual addresses areunique within the same or other Local Area Networks. (See alsoLocal Address Administration.)Group Address An LLC address that identifies a group of network nodes on a LocalArea Network.Host A computer or workstation that communicates with stations such asPLCs or CNCs across a network, especially one that performssupervisory or control functions. Note that this same term is widelyused in TCP/IP literature to refer to any network node that can be asource or destination for network messages. (See also Hostid.)Hostid The hostid is the part of the IP address identifying the host on thenetwork. (See also Netid.)IEEE 802 The IEEE 802 LAN series of standards are as follows:IEEE 802.1 Overview and Architecture.IEEE 802.2 The Logical Link Control (LLC) sublayer of OSI Data Link Layercommon above all IEEE 802 Medium Access Control (MAC)sublayers.IEEE 802.3 CSMA/CD (Ethernet) MAC and Physical Layer standard.IEEE 802.4 Token Bus (MAP LANs) MAC and Physical Layer standard.IEEE 802.5 Token Ring (IBM) MAC and Physical Layer standard.Information Field That part of a protocol data unit (PDU) that contains data, as opposedto the address field and command field.Initiating Station The station from which an instance of communication (a transaction)originates. Also referred to as “client.”Interface Shortened form for “Ethernet Interface”. The general term used inthis manual to identify the GEnet hardware module, with or withoutsoftware, that connects a PLC (or CNC) to a network. (See also LANInterface.)Internet Any collection of networks and gateways that use the TCP/IPprotocols and function as a single, cooperative virtual network,specifically, the world-wide Connected Internet.Internet Address A unique Internet address identifies each node on an IP network (orsystem of connected networks). The Internet address is assigned tothe node by the user. (Also known as an IP address.) (See alsoPhysical Address.)