Rockwell Automation 1771-IL Installation Instructions User Manual

Page 9

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Isolated Analog Input Module

9

Publication 1771Ć5.62 - November 1998

Use the following table to read data from your input module.

Dec. Bits

15 14 13 12 11 10 09 08 07 06 05 04

03

02

01

00

Description

Octal Bits

17 16 15 14 13 12 11 10 07 06 05 04

03

02

01

00

Description

Word 1

Not Used

A

HF IA

IF RTS IS OR PU

Diagnostics

Alarm violation status bit - (A) This bit is set if one or

more channels are in an alarm condition.

Hardware fault - (HF) When this bit is set, the dc/dc converter

fuse has blown. Digital logic will continue to operate.

Invalid alarm bit - (IA) This bit is set if any alarm value is unusable,

such as expecting BCD and value is in 2's complement binary.
Invalid filter bit - (IF) This bit is set if the filter parameters are not correct.

The value must be between 00 and 99 (0.00 and 0.99 seconds) in BCD, or

between 0 and 255 (0 to 2.55) in binary.
Real time sample fault bit - (RTS) This bit is set if the module is configured for

RTS and a block transfer read has not occurred within the user-programmed period.

Power up bit - (PU) Used by the module to tell the

processor that it is alive but not yet configured. It is

a key element in the application program.

Out of range bit - (OR) This bit is sent to tell the

processor that one or more channels are either

over or under range.

Invalid scaling bit - (IS) This bit reports that the scaling

is somehow invalid. Usually, both values are equal or

minimum is greater than maximum when this bit comes

on. Can also be an invalid filter value.

Octal Bits

17 16 15 14 13 12 11 10 07 06 05 04

03

02

01

00

Description

2

Not Used

8

7

6

5

4

3

2

1

Data underrange for channels 1-8

3

Not Used

8

7

6

5

4

3

2

1

Data overrange for channels 1-8

Underrange bits for each channel. Bit 00 for channel 1, bit 01 for channel

2, etc. These bits are set (1) at approximately the input range limits shown

on the right.

Overrange bits for each channel. Bit 00 for channel 1, bit 01 for channel

2, etc. These bits are set (1) at approximately the input range limits shown

on the right.

1 to 5V dc, 4 to 20mA (default)
0 to 5V dc, 0 to 20mA
Ć5 to +5V dc, Ć20 to +20mA
Ć10 to +10V dc, 0 to 10V dc

4

Not Used

8

7

6

5

4

3

2

1

Data polarity for channels 1 8

Polarity bits - Set when input is less than zero.

Data polarity for channels 1-8

5

Channel 1 Input

Channel 1 Input

6

Channel 2 Input

Channel 2 Input

⇓ ⇓

12

Channel 8 Input

Channel 8 Input

13

Not Used

8

7

6

5

4

3

2

1

Low Alarm Bits

14

Not Used

8

7

6

5

4

3

2

1

High Alarm Bits

Low Alarm bits for channels 1 through 8 respectively. Each bit represents

an alarm indicator for that channel. When the bit is set, the value of that

channel is below the low alarm value.

High Alarm bits for channels 1 through 8 respectively. Each bit represents an

alarm indicator for that channel. When the bit is set, the value of that channel is

above the high alarm value.

15

8

7

6

5

4

3

2

1

CF EF

Not Used

S

G

O

Calibration Status Bits

Calibration Fault - (CF) When this bit is set, the module could

not perform offset or gain calibration. This bit is set when a save

is requested.

EEPROM Fault - (EF) When this bit is set, the calibration values

could not be saved to EEPROM.

Offset Calibration Complete - (O) When

this bit is set, the offset calibration request

was successfully completed.

Gain Calibration Complete - (G) When

this bit is set, the gain calibration request

was successfully completed.

Save Complete - (S) When this bit is

set, the save calibration values to

EEPROM" was successfully completed.

Calibration Inhibited. Bits 8 (10) through 15 (17) represent a

channel that was not calibrated, either due to an error or a user

request. If the channel was requested not to be calibrated, these

bits confirm that request.

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