Rockwell Automation 1771-IFF/A INSTL.INSTR FAST ANALOG INPUT User Manual

Page 12

Publication 1771-IN046B-EN-P - December 2003

12 Fast Analog Input Module

differential wiring

Functional Ground

– Unused channels must have their + and

- inputs jumpered together and tied to
module common to reduce noise.

1771-WG
Field W iring Arm

Note:

The 1771-IFF module does not supply loop power for the input device.
The user must supply loop power for loop-powered input devices.

–

Channel 1+
Channel 1-
Channel 2+

Channel 2-

Channel 3+
Channel 3-
Channel 4+
Channel 4-

Channel 5+
Channel 5-
Channel 6+

Channel 6-

Channel 7+
Channel 7-

Channel 8+
Channel 8-

Module Common

Not used

Module Common

1
2
3
4
5

6
7

8
9

11
12
13

14
15

17
18

19
20
21

Configuring the module for differential inputs does not provide isolation.

–

Tie power supply grounds together to
minimize ground loops.

Note: Refer to transmitter manufacturers

specifications for power supply connections.

Power
Supply

2-Wire
Transmitter

Power
Supply

2-Wire
Transmitter

–

The sensor cable must be shielded. The shield must:

extend the length of the cable, but be connected only at the 1771 I/O chassis
extend up to the point of termination

Important:

The shield should extend to the termination point, exposing just enough
cable to adequately terminate the inner conductors. Use heat shrink or
another suitable insulation where the wire exits the cable jacket.

– Unused channels must have their + and

- inputs jumpered together and tied to
module common to reduce noise.

1771-WG
Field Wiring Arm

Note:

The 1771-IFF module does not supply loop power for the input device.
The user must supply loop power for loop-powered input devices.

–

Channel 1+
Channel 1-
Channel 2+

Channel 2-

Channel 3+
Channel 3-
Channel 4+
Channel 4-

Channel 5+
Channel 5-
Channel 6+

Channel 6-

Channel 7+
Channel 7-

Channel 8+
Channel 8-

Module Common

Not used

Module Common

1
2
3
4
5

6
7

8
9

11
12
13

14
15

17
18

19
20
21

Configuring the module for differential inputs does not provide isolation.

–

Tie power supply grounds together to
minimize ground loops.

Note: Refer to transmitter manufacturers

specifications for power supply connections.

–

The sensor cable must be shielded. The shield must:

extend the length of the cable, but be connected only at the 1771 I/O chassis
extend up to the point of termination

Important:

Power
Supply

4-Wire
Transmitter

Power
Supply

4-Wire
Transmitter

Connection Diagram for 8 Differential Inputs and Two-Wire Transmitters

Connection Diagram for 8 Differential Inputs and Four-Wire Transmitters

Functional Ground