Range selection, Safe state value selection, Data format – Rockwell Automation 1794-IE4XOE2,1794-IE8,1794-OE4,D17946.5.2 FLEX I/O ANALOG MODULE User Manual

Page 34: Reading data from your module

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4–2

Writing Configuration to and Reading Status from Your Module with a Remote I/O Adapter

Publication 1794Ć6.5.2 - May 1996

Individual input channels are configurable to operate with the
following voltage or current ranges:

Bit Settings

Ranges

Configure

Select

Full Range

0-10V dc/0-20mA

0

1

4-20mA

1

0

Ć10 to +10V dc

1

1

Off

0

0

1

When configured to Off, individual output channels will drive 0V/0mA.

!

ATTENTION: If using Series A modules, do not use
configure select and full range bit settings of 0.
Individual channels revert to 4–20mA with bit
selections of all zeroes. This could result in unwanted
or incorrect action.

You can select individual channel ranges using the designated words
of the write block transfer instruction. Refer to the Bit/Word
description for your particular module for word and bit numbers.

You can select the analog values that your output module will
maintain in the event of a network communication error. When the
multiplex control bits (M) are cleared simultaneously by a
communication error, (or by the user), the analog outputs will
automatically switch to the values set in the safe state analog words.
This allows you to define a safe operating state for controlled
devices which depend on the analog output from the module.

The data returned from the analog-to-digital converter in the module
is 12-bit resolute. This value is left-justified into a 16-bit field,
reserving the most significant bit for a sign bit. The 4–20mA mode
scales in the module and uses all 16 bits.

Refer to Appendix C for a table of values for various current and
voltage modes, and an example of scaling to engineering terms.

Read programming moves status and data from the module to the
processor’s data table. The processor’s user program initiates the
request to transfer data from the input module to the processor.

Range Selection

Safe State Value Selection

Data Format

Reading Data From Your

Module

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