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Rockwell Automation 1746-NI8 SLC 500 Analog Input Modules User Manual User Manual

Page 28

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3–7

Installation and Wiring

Publication 1746Ć6.8 - April 1997

Wiring SingleĆEnded and Differential Inputs

The diagram below shows typical wiring for the module.

shield

shield

shield

shield

shield

shield

shield

shield

singleĆend

signal source

singleĆend

signal source

singleĆend

signal source

singleĆend

signal source

differential

signal source

differential

signal source

differential

signal source

differential

signal source

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+

+

+

+

+

+

+

Shield

Channel 0

Channel 2

Channel 1

Channel 3

Channel 4

Channel 5

Channel 6

Channel 7

Shield

Important: Follow these guidelines when wiring the module.

Use shielded communication cable (Belden 8761) and keep length as short as possible.

Connect only one end of the cable shield to earth ground.

Connect the shield drain wires for channels 0-3 to the top shield terminal.

Connect the shield drain wires for channels 4-7 to the bottom shield terminal.

Shield terminals are internally connected to chassis ground which is connected to earth ground via the SLC backplane.

SingleĆended source commons may be jumpered together at the terminal block.

Channels are not isolated from each other.

If a differential signal source has an analog common, it can not and must not be connected to the module.

Common mode voltage range is $10.5 volts. The voltage between any two terminals must be less than 21 volts.

The module does not provide power for the analog inputs.

Use a power supply that matches the transmitter (sensor) specifications.

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+

+

+

+

+

+

+

+

+

+

+

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Power

Supply

Connections