Parker CM0504, Руководство пользователя

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CM0504 User Guide
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4.1.2. Analog Inputs Connections
Analog•inputs•are•susceptible•to•system•noise,•which•can•affect•the•accuracy•of•the•signal.•Signal•
accuracy•can•also•be•affected•by•ground•level•shift,•which•can•cause•inputs•to•activate•when•they•
shouldn’t.•
System noise
To•prevent•noise•pickup•on•the•sensors,•
• • Use•the•shortest•possible•wires•when•connecting•analog•inputs•to•sensors.
The•following•shows•how•to•connect•an•analog•input•to•reduce•system•noise:
Internal to product
Sensor Power
Sensor Ground
Sensor
Analog Input
•
Figure 4.1. Analog input for system noise reduction
Ground level shift
To•reduce•ground•level•shift:
1.• Dedicate•one•of•the•2•system•ground•inputs•(GND)•to•sensors•that•have•dedicated•ground•wires,•and•
connect•all•sensor•grounds•to•this•system•ground•input.
2.• Splice•the•other•system•ground•inputs•together•in•the•vehicle•harness•(close•to•the•connector)•to•
provide•a•better•ground•for•the•noisier•low-side•outputs•and•digital•circuits.
3.• Position•the•sensor’s•ground•connection•near•the•system•ground•connections•to•ensure•that•the•
signal•remains•within•the•digital•activation•range•of•the•input.
Note 1:
The•system•ground•inputs•are•rated•for•low-current•signals,•which•ensures•the•sensor’s•ground•is•
very•close•in•voltage•potential•to•the•system•ground.
Note 2: Sensors•that•don’t•have•a•dedicated•ground•wire•are•typically•grounded•to•the•vehicle•chassis•
through•the•sensor’s•body.
•