PAXUSB00 datasheet(18/32 Pages) REDLION

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RATE INPUT VALUE FOR SCALING POINT 2

Enter the corresponding Rate Input Value for the second Scaling Point by

using the arrow keys. Rate Input values for scaling points can be entered by

using the Key-in or the Applied method described below.

Key-in Method:

Enter the Rate Input value () that corresponds to the entered Rate

Display value () by pressing the

F1 or F2 keys. This value is always in

pulses per second (Hz).

Applied Method:

Apply an external rate signal to the appropriate input terminals. At the Rate

Input Value () press and hold the

F1 and F2 keys at the same time. The

applied input frequency (in Hz) will appear on the display. (To verify correct

reading wait for at least the length of the Low Update Time. Then press and

hold the

F1 and F2 keys at the same time again. The new value should be ±

0.1% of the previous entered value.) Press

PAR to enter the displayed

frequency as the Rate Input value. To prevent the displayed value from being

entered, press

DSP. This will take the meter out of Programming Mode and the

previous Rate Input value will remain.







 

Rounding values other than one round the Rate display to the nearest

increment selected (e.g. rounding of ‘5’ causes 122 to round to 120 and 123 to

round to 125). Rounding starts at the least significant digit of the Rate display.

RATE DISPLAY ROUND









The Low Cut Out value forces the Rate display to zero when the Rate display

falls below the value entered.

LOW CUT OUT











to 



to 

When the Rate value is above the present Maximum rate value for the

entered amount of time, the meter will capture that Rate value as the new

Maximum value. A delay time helps to avoid false captures of sudden short

spikes. Maximum detection will only function if Rate is assigned to Input A or

B. The Maximum rate value is shown with an annunciator of ‘’ in the display

and will continue to function independent of being displayed.

MAXIMUM CAPTURE DELAY TIME











to  seconds

When the Rate value is below the present Minimum rate value for the entered

amount of time, the meter will capture that Rate value as the new Minimum

value. A delay time helps to avoid false captures of sudden short spikes.

Minimum detection will only function if Rate is assigned to Input A or B. The

Minimum rate value is shown with an annunciator of ‘’ in the display and will

continue to function independent of being displayed.

MINIMUM CAPTURE DELAY TIME











to  seconds

RATE SCALING

To scale the Rate, enter a Scaling Display value with a corresponding Scaling

Input value. (The Display and Input values can be entered by Key-in or Applied

Methods.) These values are internally plotted to a Display value of 0 and Input

value of 0 Hz. A linear relationship is formed between these points to yield a

rate display value that corresponds to the incoming input signal rate. The PAXI

and PAXR are capable of showing a rate display value for any linear process.

KEY-IN SCALING METHOD CALCULATION

If a display value versus input signal (in pulses per second) is known, then

those values can be entered into Scaling Display (x) and Scaling Input

(x). No further calculations are needed.

If only the number of pulses per ‘single’ unit (i.e. # of pulses per foot) is

known, then it can be entered as the Scaling Input value and the Scaling Display

value will be entered as the following:

NOTES:

1. If # of pulse per unit is less than 10, then multiply both Input and Display

values by 10.

2. If # of pulse per unit is less than 1, then multiply both Input and Display

values by 100.

3. If the Display value is raised or lowered, then Input value must be raised

or lowered by the same proportion (i.e. Display value for per hour is

entered by a third less (1200) then Input value is a third less of # of pulses

per unit). The same is true if the Input value is raised or lowered, then

Display value must be raised or lowered by the same proportion.

4. Both values must be greater than 0.0.

EXAMPLE:

1. With 15.1 pulses per foot, show feet per minute in tenths. Scaling Display

= 60.0 Scaling Input = 15.1.

2. With 0.25 pulses per gallon, show whole gallons per hour. (To have greater

accuracy, multiply both Input and Display values by 10.) Scaling Display

= 36000 Scaling Input = 2.5.

INPUT FREQUENCY CALCULATION

The meter determines the input frequency by summing the number of falling

edges received during a sample period of time. The sample period begins on the

first falling edge. At this falling edge, the meter starts accumulating time

towards Low Update and High Update values. Also, the meter starts

accumulating the number of falling edges. When the time reaches the Low

Update Time value, the meter looks for one more falling edge to end the sample

period. If a falling edge occurs (before the High Update Time value is reached),

the Rate display will update to the new value and the next sample period will

start on the same edge. If the High Update Time value is reached (without

receiving a falling edge after reaching Low Update Time), then the sample

period will end but the Rate display will be forced to zero. The High Update

Time value must be greater than the Low Update Time value. Both values must

be greater than 0.0. The input frequency calculated during the sample period, is

then shown as a Rate value determined by either scaling method.

RATE DISPLAY EXCEEDED

If the rate of the input signal causes a display that exceeds the capacity of the

Rate display (5 digits, 99999), then the display will indicate an overflow

condition by showing “ ”. During this overflow condition, the Minimum

and Maximum rate values will stay at their values even during resets.















# of pulses per unit

3600

Hour

# of pulses per unit

Minute

# of pulses per unit

Second

INPUT (x)

DISPLAY (x)

RATE PER

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