Rockwell Automation Allen-Bradley 1769-IF4, Руководство пользователя

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Publication 1769-UM002B-EN-P - July 2005
Module Data, Status, and Channel Configuration for the Output Modules 4-9
If this selection is enabled [the bit is set (1)] and the system enters the fault
mode, it commands the module to convert the
user-specified integer value from
the channel’s fault value word (2 or 4) to the appropriate analog output for the
range selected. If the default value, 0000, is entered, the output typically
converts to the minimum value for the range selected.
1769-OF2 Program/Idle Mode (PM0 and PM1)
This configuration selection provides individual program/idle mode selection
for the analog channels 0 (word 0, bit 2) and 1 (word 1, bit 2). When this
selection is disabled [the bit is reset (0)], the module
holds the last state , meaning
that the analog output remains at the last converted value prior to the
condition that caused the control system to enter the program mode.
EXAMPLE
•
If the raw/proportional or engineering units data
format is selected and zero (0000) is entered in the
±10V dc operating range, the resulting value would be
0V dc.
•
If the raw/proportional or engineering units format is
selected and zero is entered as the fault value in either a
1 to 5V dc or 4 to 20 mA range, a configuration error
results.
•
See Table 4.5 1769-OF2 Valid Output Data Table on
page 4-12 for more examples.
TIP
Not all controllers support this function. Refer to your
controller’s user manual for details.
IMPORTANT
Hold last state is the default condition for the 1769-OF2
during a control system run-to-program 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 program mode.