Parker PHD Series User Manual

20 PHD
Inputs
3.3.3. PHD50/PHD70 frequency input capabilities
The PHD50 and PHD70 have 2 frequency inputs. These inputs are also
configurable as digital inputs. The frequency inputs are ideal for use with hall-
effect type sensors.
The following table provides specifications for the frequency inputs:
Frequency Input Specifications
Item
MIN
NOM
MAX
UNIT
Input range
0
5
32
V
Negative threshold
1.545
V
Positive threshold
4.008
V
Input capacitance at pin
0.1
µF
Over-voltage
36
V
Frequency accuracy
3
%
Frequency range (see note)
0
1500
Hz
Pull-up resistor to min 4.3V, max 5V
1.2
kΩ
Pull-down resistor
26.2
kΩ
Note: Electrically signals to 0 are possible, but the software will limit the minimum
measurable frequency
3.3.3.1. DC-Coupled Frequency Input Connections
When connecting DC-coupled frequency inputs, be aware of system noise and
ground level shift.
System Noise
DC-coupled frequency inputs are more susceptible to system noise than digital
inputs.
To reduce system noise:
▪ Connect DC-coupled frequency inputs to sensors that produce signals with no
DC offset.
▪ Use the shortest possible wires when connecting DC-coupled frequency inputs
to sensors to prevent noise pickup on the sensors.
Ground Level Shift
Ground level shift affects the accuracy of DC-coupled frequency inputs. Ground
level shift refers to the difference between the system ground input (GND)
voltage, and the sensor ground voltage.

Parker PHD Series Specifications

General

Brand	Parker
Model	PHD Series
Category	Control Unit
Language	English