FUTEK IPM500 (D500) Digital Display - Manual (Page 54)

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Menu Mode The meter programming mode used for input and range selection, meter setup,
and meter configuration. Entered into from the Run mode by pressing the
MENU
key. The Menu mode can be locked out completely by a jumper.
Meter Hold A rear panel input which freezes the meter display and all meter outputs while
that input is tied to logic ground by a switch or is held at 0V (logic level true).
The meter will resume operation when the input is allowed to float or is held at
+5V (logic level false).
Modbus
An industry-standard serial communications protocol which allows devices by
different manufacturers to be digitally addressed by a PC on the same com-
munication line, with up to 247 digital addresses. More complex than the
Custom ASCII
protocol, which is also supported by these meters.
Moving Average Filter
A digital filter mode which displays a weighting moving average of readings.
Readings are taken at 60/sec with 60 Hz power and 50/sec with 50 Hz power.
Display update rates remain 3.5/sec with 60 Hz power and 3.0/sec with 50 Hz
power. There are eight moving average modes:
Old average x 1/2 + new reading x 1/2 (equivalent to 0.08 sec RC time constant).
Old average x 3/4 + new reading x 1/4 (equivalent to 0.15 sec RC time constant).
Old average x 7/8 + new reading x 1/8 (equivalent to 0.3 sec RC time constant).
Old average x 15/16 + new reading x 1/16 (equivalent to 0.6 sec RC time constant).
Old average x 31/32 + new reading x 1/32 (equivalent to 1.2 sec RC time constant).
Old average x 63/64 + new reading x 1/64 (equivalent to 2.4 sec RC time constant).
Old avg. x 127/128 + new reading x 1/128 (equivalent to 4.8 sec RC time constant).
Old avg. x 255/256 + new reading x 1/256 (equivalent to 9.6 sec RC time constant).
Offset A constant adder used for the displayed reading. This is the term b in the
straight line formula y = mx + b, where y is the displayed reading in counts, m
is the scale factor, x is the measured reading in counts, and b is the offset. For
direct readout in (milli)volts or (milli)amps, offset is 0.
Peak Display The maximum (or most positive) reading since that maximum was last reset.
Reset can be via the meter front panel, an external input, or a software
command. The displayed value can reflect the filtered or unfiltered readings.
Process Signal
A signal whose display requires setup of scale and offset settings for display in
engineering units. A classical process signal is 4-20 mA, where the 4 mA and
20 mA end points can each correspond to a desired meter reading.
Rate of Change Meter
A
configuration mode of the Extended meter which allows the display of rate
based on successive readings. The conversion to engineering units is achieved
with the combination of a multiplier from 0.1 to 10,000 and a scale factor.
Reading The value displayed by the meter. “Taking a reading” is the action of the meter
to make an analog-to-digital conversion. Readings are taken at 60/sec with 60
Hz power or 50/sec with 50 Hz power, and are displayed with an update rate of
3.5/sec with 60 Hz power or 3.0/sec with 50 Hz power.