Electro Industries/GaugeTech Nexus 1250, Installation & Operation Manual

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Term Definition
NVRAM NVRAM (Non-volatile Random Access Memory) is able to
keep the stored values in memory even with the loss of circuit or
control power. High speed NVRAM is used in the Nexus to
gather measured information and to insure that no information is
lost.
Protocol The language that will be spoken between two or more devices
connected on the network.
Quadrant
(Programmable
Values and Factors
on the Nexus) Watt and VAR flow is typically represented using an X-Y
coordinate system. The four corners of the X-Y plane are
referred to as a quadrants. Most power applications label the
upper right hand corner as the first quadrant and number the
remaining quadrants in a counter-clockwise rotation. Following
are the positions of the quadrants: 1st - upper right, 2nd - upper
left, 3rd - lower left and 4th - lower right. Power flow is
generally positive in quadrants 1 and 4. VAR flow is positive in
quadrants 1 and 2. The most common load conditions are:
Quadrant 1 - power flow positive, VAR flow positive, inductive
load, lagging or positive power factor; and Quadrant 2 - power
flow negative, VAR flow positive, capacitive load, leading or
negative power factor.
RS-232 A type of serial network connection that connects two devices to
enable communications between devices. An RS-232
connection connects only two pints. 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-485 A type of serial network connection that connects two or more
devices to enable communications between the devices. An RS-
485 connection will allow multi-drop communications 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.
Courtesy of NationalSwitchgear.com