Parker CM2115, User Manual

Page: 32 / 90

22 CM2115
Inputs
5.5. CM2115 DC-Coupled Frequency Input
There is one type of frequency input in the CM2115:
 DC-coupled frequency input
The input detects frequency signals that are pre-conditioned to fall within the DC
threshold ranges of the input. Unlike an AC-coupled input, this input is used with
frequency sensors that switch between system ground and sensor/battery power.
Typical sensor types are Hall Effect.
The CM2115 has one DC-coupled frequency input:
 INPUT8_DF
5.5.1. CM2115 DC-Coupled Frequency Input Capabilities
A DC-coupled frequency input allows you to read the frequency of external
signals that switch between system ground, and sensor or battery power. This
input is ideal for use with hall-effect type sensors.
The following table provides specifications for the CM2115's DC-coupled
frequency input:
DC-Coupled Frequency Input Specifications
Item MIN NOM MAX UNIT
Input voltage range 0 - 32 V
Pull-up/pull-down resistance 5.31 5.36 5.41 k Ω
Capacitance at pin - .005 µF
Over-voltage - - 36 V
Frequency accuracy - - 5 %
Frequency range 1 - 10000 Hz
Negative going threshold - - 1.56 V
Positive going threshold 3.82 - - V
5.5.2. CM2115 DC-Coupled Frequency Input Configuration
The DC-coupled frequency input can be configured to use a pull-up resistor, pull-
down resistor or neither.