RPS-500 Analog Ranging Card0 pages

RPS-500
Features
Analog Ranging Card

Ranges 2"-14", 5"-36", 5"-72", 10"-240"

2500 Volts Isolation

Inverting Switch

0 -10 VDC Analog Voltage

Zero, Span, Sample & Hold Controls

4 - 20 mA Analog Current

120VAC or 24VDC Power Input

The RPS-500 ranging board was designed to give
analog voltage and current outputs proportional to
distance and can be used with the RPS-100, RPS300, RPS-325 or RPS-326. It is a fast, accurate
means of converting analog pulse width generated
by the ultrasonic sensor into analog voltage and
current. Ranges available are 2" to14", 5" to 36", 5"
to 72", 10" to 240"
ZERO & SPAN CONTROLS
The RPS-500 analog card comes with a zero and
span control. These two potentiometers allow the
analog signal to be adjusted over a desired range.
The adjustment ratio is 5:1. This means that the RPS500-14 (range 2" to 14") can be adjusted to give an
analog output over a range as small as 2.4" or as
large as 12". Example: If you desired a 4mA signal
at 4" and a 20mA signal at 14" you would adjust the
analog card as follows. Place a target at 4" and adjust
the zero control until your current meter reads 4mA.
Move the target to 14" and adjust the span control
until you reach 20mA. With no more than two
adjustments of each potentiometer the desired range
will be achieved. If the analog card is in the inverted
state, voltage and current decreasing with distance,
the zero pot will adjust the 20mA point and the span
pot will adjust the 4mA point. Always adjust the close
point first
INVERTING ANALOG SIGNALS
Both the current and voltage outputs of the analog
RPS-500 card can be inverted. In the non-inverted
state (switch 1 ON switch 2 ON) the voltage and
current increase with distance. In the inverted state
( switch 1 OFF switch 2 OFF) the voltage and current
decrease with distance. Note: The inverting switches
should be set in the desired positions before begining
adjustments with the zero and span controls.

Migatron Corporation - 1997

SAMPLE AND HOLD
After each return echo the output voltage and
current are updated. If no echo is received the previous readings are maintained or held. The time these
readings are maintained will depend on the setting of
the hold potentiometer, cw (up to 5 seconds). After this
time has elapsed, the outputs will go to there maximum
readings, indicating that there is no return echo. The
advantage of this control is that it allows an echo or
echos to be missed for a time without changing the
output readings. This has proven to be advantageous
in level control where the surface may be agitated.
LED DISPLAY
This 10 segment LED display will tell when a return
echo is in the range of the sensor. For example, when
the RPS-500 card is used with the RPS-300-14 and
the target is 4 inches away just 1 or 2 LEDs will be on.
When the target moves to 9 inches about 1/2 of the
display will be on, and when the target is 14" away all
the LEDs will be on.
ENABLE LINE
When the enable line is held high (high = 3 to 30V)
the sensors will not transmit and the hold circuit will
time out, causing the outputs to go to a maximum
reading. A short time (Approximately 4.2mS) after the
enable line is pulled low (low = 0 to 1V) the sensors will
transmit. When a return echo is received the outputs
will be updapted.

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500B