Rockwell Automation 1794-XXXX FLEX I/O High-Density Analog Modules - Manual (Page 36)

Publication 1794-UM062A-EN-P - September 2012
28 Write Configuration to and Read Status from Your Module
Range Selection Individual input channels are configurable to operate with the following voltage
or current ranges.
You can select individual channel ranges using the designated words of the write
block transfer instruction. See the Word/Bit Descriptions for your particular
module for word and bit numbers.
Safe State Value Selection You can select the analog values that your output module maintains 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 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.
Data Format 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…20 mA mode scales in the module and uses all
16 bits.
For more information on values for various current and voltage modes, and an
example of scaling to engineering terms, see
Module Programming on page 67 .
Read Data From Your
Module Read programming transmits status and data from the analog module to the
processor data table in one I/O scan. The processor user program initiates the
request to the transfer data from the analog module to the processor.
Voltage and Current Ranges
Ranges Bit Settings
Configure Select Full Range
0…10V DC / 0…20 mA 0 1
4…20 mA 1 0
-10…+10V DC 1 1
Off
(1)
(1) When configured to OFF, individual output channels drive 0V or 0 mA.
0 0
ATTENTION: If using Series A modules, do not use configure select
and full range bit settings of 0. Individual channels revert to 4…20
mA with bit selections of all zeroes. This could result in unwanted or
incorrect action.