ES-1375 Rev.17

PRU

Plug-in Signal Conditioners M-UNIT

PULSE SCALER

(field-configurable)
Functions & Features
• Converting pulse rate into convenient engineering unit for display on a totalizing counter or meter
• Excitation
• Digital scaling accuracy
• Scaling factor adjustable of 0.9999 × 100 to 0.0001 × 10–6
• High-density mounting
Typical Applications
• Positive displacement flowmeters and turbine flowmeters
• Magnetic tachometers
 

MODEL: PRU–[1][2]–[3][4]

ORDERING INFORMATION

• Code number: PRU-[1][2]-[3][4]
Specify a code from below for each of [1] through [4].
  (e.g. PRU-11-B/Q)
• Input frequency range (e.g. 0 – 356.7 Hz)
• Output frequency range (e.g. 0 – 1.00 Hz)
• Specify the specification for option code /Q
  (e.g. /C01/S01)

[1] INPUT

1: Dry contact (Excitation 12 V @30 mA)
2: DISCONTINUED, replaced with code 8
Voltage pulse; square wave (Exitation 12 V @30 mA)
7: Sine wave (Excitation 12 V @30 mA)
8: Voltage pulse; square wave (Excitation 12 V @30 mA)

[2] OUTPUT

1: Open collector (max. frequency 20 kHz)
2: 5 V pulse (max. frequency 20 kHz)
3: Relay contact (max. frequency 2 Hz)
4: 24 V pulse (max. frequency 20 Hz)

[3] POWER INPUT

AC Power
B: 100 V AC
C: 110 V AC
D: 115 V AC
F: 120 V AC
G: 200 V AC
H: 220 V AC
J: 240 V AC
DC Power
S: 12 V DC
R: 24 V DC
V: 48 V DC

[4] OPTIONS

blank: none
/Q: With options (specify the specification)

SPECIFICATIONS OF OPTION: Q (multiple selections)

COATING (For the detail, refer to our web site.)
/C01: Silicone coating
/C02: Polyurethane coating
/C03: Rubber coating
TERMINAL SCREW MATERIAL
/S01: Stainless steel

CAUTION

1) This unit's output waveform is not uniform due to its scaling method.  The user must be aware that it may be inconvenient for certain types of application.
2) This unit is designed to accept at the maximum of 100 kHz, which may cause errors due to chattering in the input pulses.
Use input relays which do not cause chattering. Other relays could be used only with a CR filter, for 10 Hz at maximum.
3) Use the Model M2PRU instead of this unit in conjunction with the pulse output from our power transducers.

GENERAL SPECIFICATIONS

Construction: Plug-in
Connection: M3.5 screw terminals
Screw terminal: Chromated steel (standard) or stainless steel
Housing material: Flame-resistant resin (black)
Isolation: Input to output to power
Input pulse sensing: Capacitor coupled; detecting pulse rise
Sensitivity adjustment: For voltage pulse input, sine wave input, adjustable between 25 mVp-p – 5 Vp-p (front)
Scaling factor adjustment: 0.9999 × 100 – 0.0001 × 10–6 (front 10-position rotary switch)
Output pulse width adjustment: (front)
• Open collector, 5 V pulse: 40 μsec. - 0.8 msec.
• Relay contact, 24 V pulse: 40 msec. - 0.8 sec.

INPUT SPECIFICATIONS

Excitation: 12 V DC @30 mA; shortcircuit protection
Dry Contact: Mechanical contact or open collector
Max. frequency: 100 kHz
Pulse width time requirement: 5 μsec. min. (20 msec. min. for frequencies ≤ 10 Hz)
Sensing: Approx. 7.5 V DC @ 1 mA
ON/OFF level: ≤ 20 kΩ for ON, ≥ 100 kΩ for OFF
Voltage Pulse: Square or similar waveform
Max. frequency: 100 kHz
Pulse width time requirement: 5 μsec. min. (20 msec. min. for frequencies ≤ 10 Hz)
Input amplitude: 25 mVp-p – 50 Vp-p
Minimum amplitude requirement:
[Pulse With (Fequency): Amplitude]
≥ 250 μsec. (0 – 2 kHz): 25 mVp-p
≥ 25 μsec. (0 – 20 kHz): 50 mVp-p
≥ 12.5 μsec. (0 – 40 kHz): 1 Vp-p
≥ 5 μsec. 0 – (100 kHz): 5 Vp-p
Input impedance: ≥ 50 kΩ
Sine wave: Sine or similar waveform
Frequency: 10 Hz - 100 kHz
Pulse width time requirement: 5 μsec. min. (20 msec. min. for frequencies ≤ 10 Hz)
Input amplitude: 25 mVp-p – 50 Vp-p
(within 10 Hz - 100 kHz)
Minimum amplitude requirement: (Frequency: Amplitude)
0 – 2 kHz: 25 mVp-p
0 – 20 kHz: 50 mVp-p
0 – 40 kHz: 1 Vp-p
0 – 100 kHz: 5 Vp-p
Input impedance: ≥ 50 kΩ
Waveform examples

OUTPUT SPECIFICATIONS

■ Open Collector: 50 V DC @ 50 mA (resistive load)
Frequency range: 0 – 20 kHz
ON pulse width: 40 μsec. – 0.8 msec. adjustable
Saturation voltage: 0.6 V DC
Relay Contact: 120 V AC @ 200 mA (cos ø = 1)
240 V AC @ 100 mA (cos ø = 1)
24 V DC @ 200 mA (resistive load)
Frequency range: 0 – 2 Hz
ON pulse width: 40 msec. – 0.8 sec. adjustable
Relay life:
≥ 5 × 107 cycles (mechanical)
≥ 105 cycles (electrical)
5 V Pulse
Frequency range: 0 – 20 kHz
Low pulse width: 40 μsec. – 0.8 msec. adjustable
Hi/Lo level: 5 V ± 10 % for Hi; ≤ 0.5 V for Lo
Load resistance: 600 Ω min.
24 V Pulse
Frequency range: 0 – 20 Hz
High pulse width: 40 msec. – 0.8 sec. adjustable
Hi/Lo level: 24 V ± 10 % for Hi; ≤ 0.5 V for Lo
Load current: 30 mA max.
Load resistance: 800 Ω min.

INSTALLATION

Power input
AC: Operational voltage range: rating ±10 %,
50/60 ±2 Hz, approx. 2 VA
DC: Operational voltage range: rating ±10 %,
ripple 10 %p-p max., approx. 2 W (80 mA at 24 V)
Operating temperature: -5 to +60°C (23 to 140°F)
Operating humidity: 30 to 90 %RH (non-condensing)
Mounting: Surface or DIN rail
Weight: 350 g (0.77 lb)

PERFORMANCE

Insulation resistance: ≥ 100 MΩ with 500 V DC
Dielectric strength: 2000 V AC @1 minute  (input to output to power to ground)

EXTERNAL VIEW

EXTERNAL DIMENSIONS & TERMINAL ASSIGNMENTS unit: mm [inch]

SCHEMATIC CIRCUITRY & CONNECTION DIAGRAM