CM0504 User Guide
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The•following•shows•a•typical•variable•reluctance•connection:
Internal to product
AC Coupled Frequency Input
Variable
Reluctance
Sensor
Figure 10.8. Variable reluctance sensor connection
10.5.4. Switch
A•switch•is•a•type•of•sensor•that•uses•mechanical•contacts•in•one•of•two•states:•open•or•closed.•Sensor•
switches•are•used•to•turn•sensors•on•and•off,•and•can•be•wired•directly•to•digital•inputs.
Active-low•sensor•switches•are•common.•To•use•active-low•switches,•the•internal•pull-up•resistor•on•the•
input•that•the•sensor•is•wired•to•must•be•enabled.
••Use•of•active-low•switches•is•not•recommended.•A•broken•wire•on•this•type•of•switch,•if•it•
makes•contact•with•the•chassis,•will•activate•the•function.•
Active-high•sensor•switches•are•another•common•type•which•are•generally•safer.•To•use•active-high•
switches,•the•internal•pull-down•resistor•for•the•input•that•the•sensor•is•wired•to•must•be•enabled.
The•following•shows•a•typical•sensor•switch•connection:
•
Internal to product
Switch
Digital Input
Battery voltage
Figure 10.9. Switch sensor connection