GE EPM 9650/9800 manual Nvram

Master Device:	In Modbus communication, a Master Device initiates and controls all
	information transfer in the form of a Request Packet to a Slave Device. The
	Slave reponds to each request.
Maximum Demand:	The largest demand calculated during any interval over a billing period.
Modbus ASCII:	Alternate version of the Modbus protocol that utilizes a different data transfer
	format. This version is not dependent upon strict timing, as is the RTU version.
	This is the best choice for telecommunications applications (via modems).
Modbus RTU:	The most common form of Modbus protocol. Modbus RTU is an open protocol
	spoken by many field devices to enable devices from multiple vendors to
	communicate in a common language. Data is transmitted in a timed binary
	format, providing increased throughput and therefore, increased performance.
Network:	A communications connection between two or more devices to enable those
	devices to send and receive data to one another. In most applications, the
	network will be either a serial type or a LAN type.
NVRAM:	Nonvolatile Random Access Memory is able to keep the stored values in
	memory even during the loss of circuit or control power. High speed NVRAM
	is used in the EPM 9450, 9650 & 9800 to gather measured information and to
	insure that no information is lost.
Optical Port:	A port that facilitates infrared communication with an EPM 9800 meter.
	Using an ANSI C12.13 Type II magnetic optical communications coupler and
	an RS-232 cable from the coupler to a PC, the meter can be programmed with
	GE Communicator EXT software.
Packet:	A short fixed-length section of data that is transmitted as a unit. Example: a
	serial string of 8-bit bytes.
Percent (%) THD:	Percent Total Harmonic Distortion. (See THD.)
Protocol:	A language that will be spoken between two or more devices connected on a
	network.
PT Ratio:	Potential Transformer Ratio used to scale the value of the voltage to the primary
	side of an instrument transformer. Also referred to as VT Ratio.
Pulse:	The closing and opening of the circuit of a two-wire pulse system or the
	alternate closing and opening of one side and then the other of a three-wire
	system (which is equal to two pulses).
Q Readings:	Q is the quantity obtained by lagging the applied voltage to a wattmeter by 60
	degrees. Values are displayed on the Uncompensated Power and Q Readings
	screen.

Glossary-4