Electro-Voice 1252, 250 operation manual Glossary-5

Register:	An entry or record that stores a small amount of data.
Register Rollover:	A point at which a Register reaches its maximum value and rolls over to zero.
Reset:	Logs are cleared or new (or default) values are sent to counters or timers.
Rolling Window	The Rolling (Sliding) Window Average is the average power calculated over a
Average (Power):	user-set time interval that is derived from a specified number of sub-intervals,
	each of a specified time. For example, the average is calculated over a
	15-minute interval by calculating the sum of the average of three consecutive
	5-minute intervals. This demand calculation methodology has been adopted by
	several utilities to prevent customer manipulation of kW demand by simply
	spreading peak demand across two intervals.
RS-232:	A type of serial network connection that connects two devices to enable
	communication between devices. An RS-232 connection connects only two
	points. Distance between devices is typically limited to fairly short runs.
	Current standards recommend a maximum of 50 feet but some users have had
	success with runs up to 100 feet. Communications speed is typically in the
	range of 1200 bits per second to 57,600 bits per second. RS-232 connection
	can be accomplished using Port 1 of the Nexus 1250/1252 or the Optical Port
	on the face of the Nexus 1260/1270.
RS-485:	A type of serial network connection that connects two or more devices to enable
	communication between the devices. An RS-485 connection will allow
	multi-drop communication from one to many points. Distance between devices
	is typically limited to around 2,000 to 3,000 wire feet. Communications speed
	is typically in the range of 120 bits per second to 115,000 bits per second.
Sag:	A voltage quality event during which the RMS voltage is lower than normal for
	a period of time, typically from 1/2 cycle to 1 minute.
Secondary Rated:	Any Register or pulse output that does not use any CT or VT Ratio.
Serial Port:	The type of port used to directly interface with a PC.
Slave Device:	In Modbus communication, a Slave Device only receives a Request Packet from
	a Master Device and responds to the request. A Slave Device cannot initiate
	communication.
Swell:	A voltage quality event during which the RMS voltage is higher than normal for
	a period of time, typically from 1/2 cycle to 1 minute.
THD:	Total Harmonic Distortion is the combined effect of all harmonics measured in a
	voltage or current. The THD number is expressed as a percent of the
	fundamental. For example, a 3% THD indicates that the magnitude of all
	harmonic distortion measured equals 3% of the magnitude of the fundamental
	60Hz quantity.

e Electro Industries/Gauge Tech Doc # E107706 V1.25 Glossary-5