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Rockwell Automation 1794-APB/B FLEX I/O PROFIBUS Adapter Module User Manual User Manual

Page 41

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2–21

How Communication Takes Place and I/O Image Table Mapping

Publication 1794ĆUM057B-EN-P - November 2001

1794ĆIE4XOE2 Range Selection Bits

Channel No.

Input

Channel 0

Input

Channel 1

Input

Channel 2

Input

Channel 3

Output

Channel 0

Output

Channel 1

F0

C0

F1

C1

F2

C2

F3

C3

F4

C4

F5

C5

Decimal Bits

(Octal Bits)

00

08

(10)

01

09

(11)

02

10

(12)

03

11

(13)

04

12

(14)

05

13

(15)

4-20mA

0

1

0

1

0

1

0

1

0

1

0

1

0-10V dc/0-20mA

1

0

1

0

1

0

1

0

1

0

1

0

Ć10 to +10V dc

1

1

1

1

1

1

1

1

1

1

1

1

Off

1

0

0

0

0

0

0

0

0

0

0

0

0

C = Configure select bit

F = Full range bit

1

When configured to off, individual channels will return or send either 0V or 0mA on Series B modules. On Series modules, 2V or 4mA is output

until the module is configured.

1794ĆIE4XOE2 Word/Bit Descriptions

Word

Decimal Bit

(Octal Bit)

Definition

Read Word 1

Bits 00-14

(00-16)

Channel 0 analog data - 12Ćbit left justified two's complement number; unused

lower bits are zero; 4Ć20mA uses all 16 bits.

Bits 15 (17)

Channel 0 analog data sign bit.

Word 2

Bits 00-14

(00-16)

Channel 1 analog data - 12Ćbit left justified two's complement number; unused

lower bits are zero; 4Ć20mA uses all 16 bits.

Bits 15 (17)

Channel 1 analog data sign bit.

Word 3

Bits 00-14

(00-16)

Channel 2 analog data - 12Ćbit left justified two's complement number; unused

lower bits are zero; 4Ć20mA uses all 16 bits.

Bits 15 (17)

Channel 2 analog data sign bit.

Word 4

Bits 00-14

(00-16)

Channel 3 analog data - 12Ćbit left justified two's complement number; unused

lower bits are zero; 4Ć20mA uses all 16 bits.

Bits 15 (17)

Channel 3 analog data sign bit.

Bits 00-03

Underrange bits (U) for individual channels (4Ć20mA current inputs only) - Bit 00

corresponds to input channel 0, bit 01 corresponds to input channel 1, and so on.

When set (1), indicates either a broken or open input wire, or input current is at or

below 4mA.

Word 5

Bits 04Ć05

Wire Off bits (W) - Current outputs only - When set (1), the wire on the current

output is broken or the load resistance is too high. Bit 00 corresponds to channel 0,

bit 01 corresponds to channel 2, and so on.

Bits 06-14

(06-16)

Not used

Bit 15 (17)

Power Up bit - included in series B modules only. This bit is always 0 in series

A modules. This bit is set to 1 when all bits in the configuration register (write

word 3) are 0 (unconfigured state). The configuration register can be cleared by

either a reset, or by the user writing all zeroes to it.