CM2904 Instruction Book © 2009 - 2022 Parker-Hannifin Corporation Page 43 of 51
Application Examples
Connecting rotary encoder
Ensure that voltage range of the used sensor is within allowed range of CM2904
Analog Inputs measurement range (refer to chapter 5.2.1).
9.3.4. Potentiometer (Ratiometric) Sensors
Potentiometers and other ratiometric type sensors can be wired directly to Analog
Inputs (refer to chapter 5.2.1).
Potentiometers are resistive devices that use a wiper arm to create a voltage divider.
Changes to resistive measurements happen as the wiper arm moves along a resistive
element.
When connecting potentiometer sensors, it is important to do the following:
•
Connect one end of the sensor to CM2904 sensor supply pin:
8VOut
or
+5VOut –pin
•
Connect the other end to a sensor gnd:
X1/ Pin 11 for +8VOut
or
X2/pin 7 for +5VOut.
•
Connect the sensor signal to an analog input.
The following shows a typical potentiometer sensor connection:
Figure 13: Potentiometer (ratiometric) sensor installation connection
9.4. Connecting rotary encoder
Frequency inputs can be used for connecting incremental rotary encoder (pulse
wheel) into CM2904 by utilizing the quadrature feature of Frequency inputs.
These two signals are decoded to produce a count up pulse or a countdown pulse.
FI1 & FI2 inputs are read by CM2904 software and to decode the direction.
