Schneider Electric 890USE17700 manual

Glossary

process image	A part of the NIM firmware that serves as a real-time data area for the data exchange
	process. The process image includes an input buffer that contains current data and
	status information from the island bus and an output buffer that contains the current
	outputs for the island bus, from the fieldbus master.
producer/	In networks that observe the producer/consumer model, data packets are identified
consumer model	according to their data content rather than by their physical location. All nodes listen
	on the network and consume those data packets that have appropriate identifiers.
Profibus DP	Profibus Decentralized Peripheral. An open bus system that uses an electrical
	network based on a shielded two-wire line or an optical network based on a fiber-
	optic cable. DP transmission allows for high-speed, cyclic exchange of data between
	the controller CPU and the distributed I/O devices.

R

reflex action	A simple, logical command function configured locally on an island bus I/O module.
	Reflex actions are executed by island bus modules on data from various island
	locations, like input and output modules or the NIM. Examples of reflex actions
	include compare and copy operations.
repeater	An interconnection device that extends the permissible length of a bus.
reverse polarity	Use of a diode in a circuit to protect against damage and unintended operation in the
protection	event that the polarity of the applied power is accidentally reversed.
rms	root mean square. The effective value of an alternating current, corresponding to the
	DC value that produces the same heating effect. The rms value is computed as the
	square root of the average of the squares of the instantaneous amplitude for one
	complete cycle. For a sine wave, the rms value is 0.707 times the peak value.
role name	A customer-driven, unique logical personal identifier for an Ethernet Modbus TCP/
	IP NIM. A role name is created either as a combination of a numeric rotary switch
	setting and the STB NIP 2212 part number or by modifying text on the Configure
	Role Name web page. After the STB NIP 2212 is configured with a valid role name,
	the DHCP server will use it to identify the island at power up.
RTD	resistive temperature detect. An RTD device is a temperature transducer composed
	of conductive wire elements typically made of platinum, nickel, copper, or nickel-
	iron. An RTD device provides a variable resistance across a specified temperature
	range.

184 890USE17700 April 2004