Schneider Electric 890USE17700 - Manual (Page 21)

Introduction
890USE17700 April 2004 21
Ethernet Communications and Connectivity
Introduction The STB NIP 2212 allows the Advantys STB island to function as a node on an
Ethernet local area network (LAN).
Ethernet is an open local (communications) network that enables the interconnec-
tivity of all levels of manufacturing operations from the plant’s office to the sensors
and actuators on its floor.
Conformance The STB NIP 2212 is located on a 10Base-T LAN. The 10Base-T standard is
defined by the IEEE 802.3 Ethernet specification. Contention for 10Base-T networks
is resolved by using Carrier Sense Multiple Access with Collision Detect (CSMA/
CD).
Transmission
Rate An STB NIP 2212 island node resides on a baseband network with a transmission
rate of 10 Mbit/s.
Frame Format The STB NIP 2212 supports both Ethernet II and IEEE 802.3 frame formats;
Ethernet II is the default frame type.
Modbus over
TCP/IP
Connection
Management The STB NIP 2212 limits the number of Modbus client connections to 32. If a request
for a new connection is received and the number of existing connections is at the
limit, the oldest unused connection is closed.