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deviation band, and de-actuates when the reading falls outside. A limit (e.g., 50
counts) is set up around both sides of the setpoint to create a deviation band
(e.g., 100 counts). Setting up a passband around a setpoint is often used for
component testing. Deviation limits are programmed by entering menu item
dEU1b
for Alarm 1 and
dEU2b
for Alarm 2. The deviation band equals two limits.
Display Blank
A rear panel input which blanks the display when the input is tied to logic ground
by a switch or when 0V is applied (logic level true). The meter display will light
when the input is open or is held at +5V (logic level false).
Extended Meter
A digital panel meter with an enhanced firmware that provides added capabilities,
namely linearization of nonlinear inputs and display of rate of change from
successive readings.
Full Scale
The maximum input signal range for which the meter has been configured. For
example, the most sensitive full scale for the load cell meter is ±20 mV (signal
range from -20 mV to +20 mV).
Function Reset
The action of resetting Peak, Valley, and latched alarms. Takes about 20 msec.
Normally achieved by an external pushbutton switch, which connects a control
input 1 or 2 at the rear of the meter to digital ground. The functions of control
inputs are programmed under Setup. Peak and Valley can also be reset by
simultaneously pressing the RESET and PEAK keys. Latched alarms can also
be reset by simultaneously pressing the RESET and ALARM keys.
Ground Loop
A closed conductive path in external ground wiring that allows stray currents to
flow in ground wiring, creating ground noise. The meters in this manual minimize
ground loop problems by mutually isolating the grounds associated with meter
power, signal input, and all output and communication options.
Jumper
A push-on component which provides a short between two adjacent posts on a
circuit board. Jumpers are used to configure signal conditioner boards for specific
signal types and full scale ranges, and to configure power supply and commu-
nications boards for various modes of operation. Unused jumpers are stored by
pushing one side over an unused post.
Hysteresis, Split
Relay operation is specified symmetrically
around a setpoint. The relay closes (or opens)
when the reading rises above the setpoint plus
one hysteresis limit, and opens (or closes)
when the reading falls below the setpoint less
one hysteresis limit. A narrow hysteresis band
can be used to minimize relay chatter. A wide
hysteresis band can be used for control.
