Rockwell Automation 1769-IF4 - 1769-OF2 Fault Mode (FM0 and FM1)

Publication 1769-UM002B-EN-P - July 2005
4-8 Module Data, Status, and Channel Configuration for the Output Modules
1769-OF2 Percent Full Range
The control program presents the analog output data to the module as a
percent of the full analog output range (for example, valve 50% open). The
module scales this data to the appropriate analog output value for the selected
user range. For example, 0 to 100% equals 0 to 10V dc. See Table 4.5
1769-OF2 Valid Output Data Table on page 4-12.
1769-OF2 Output Type/Range Selection
This selection, along with proper output wiring, lets you configure each output
channel individually for current or voltage ranges, and provides the ability to
read the range selection.
1769-OF2 Fault Mode (FM0 and FM1)
This configuration selection provides individual fault mode selection for
analog output channels 0 (word 0, bit 3) and 1 (word 1, bit 3). When this
selection is disabled [the bit is reset (0)] and the system enters the fault mode,
the module holds the last output state value. This means that the analog output
remains at the last converted value prior to the condition that caused the
system to enter the fault mode.
TIP
The ±10V dc range does not support percent full range.
IMPORTANT
Hold last state is the default condition for the 1769-OF2
during a control system run-to-fault mode change.
TIP
MicroLogix 1500™ does not support the analog output
module’s default hold last state function and resets analog
outputs to zero when the system enters the fault mode.