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Channel configuration, Ladder program, Channel configuration ladder program – Rockwell Automation 1746-NI8 SLC 500 Analog Input Modules User Manual User Manual

Page 81

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Variable Content

TTL:Chap

C–3

Publication 1746Ć6.8 - April 1997

For the 1746-NI4, input selection (voltage or current) is made via a
switch. For the 1746-NI8, input selection (voltage or current) is
made via a switch and a configuration word is used to define the
other operating parameters for the module. The 1746-NI4 does not
employ a configuration word.

To configure the 1746-NI8 for the same input type as the 1746-NI4,
use the following configuration word. For voltage input you must
select

±

10V dc, and for current input you must select

±

20 mA.

Define a configuration word for channels 0–7 on the 1746-NI8
module.

Input Type

Data Format

Open Circuit

Filter Frequency

Channel Enable

Not Used

Current Input

Voltage Input

ЙЙЙЙЙЙЙ

ЙЙЙЙЙЙЙ

ЙЙЙЙЙЙЙ

11

12

13

14

15

0

0

0

0

9

10

8

6

7

4

5

0

1

2

3

0

0

0

0

Bit Number

1

1

0

0

0

1

1

1

1

0

0

0

1

1

0

0

0

1

1

0

0

0

0

0

Bit Definitions for Converting from 1746ĆNI4 to 1746ĆNI8:
Bits 0-2

Input Type

000 =

±

10V dc

110 =

±

20 mA

Bits 3- 5

Data Format

011 = 1746ĆNI4 data format

Bits 6 and 7

Open Circuit

00 = zero (the open circuit option is not available for the

±

20 mA data type)

Bits 8-10

Filter Frequency

100 = 10 Hz

Bit 11

Channel Enable

0 = channel disabled

1 = channel enabled

Bits 12-15

Not Used

0000 = always make this setting

See chapter 5 for more detailed information on channel
configuration.

To convert your ladder program from the 1746-NI4s to a 1746-NI8,
you only need to change the module addressing. Change the
addresses in the program (slot and word sub element number) to
reflect the location of the new module.

See chapter 6 for more information on ladder programming.

Channel Configuration

Ladder Program