Owner's manual

Section
5-1
5 Discrete Input (DI)
Function Block
The Discrete Input (DI) function block processes a single discrete input
from a field device and makes it available to other function blocks. You
can configure inversion and alarm detection on the input value.
The Discrete Input function block supports mode control, signal status
propagation, and simulation.
Normally, the block is used in Automatic (Auto) mode so that the
process variable (PV_D) is copied to the output (OUT_D). You can
change the mode to Manual (Man) to disconnect the field signal and
substitute a manually-entered value for OUT_D. In this case, PV_D
continues to show the value that will become OUT_D when the mode is
changed to Auto.
To support testing, you can enable simulation, which allows the
measurement value to be supplied manually through the
SIMULATE_D parameter. Figure 5-2 illustrates the internal
components of the DI function block, and Table 5-1 lists the definitions
of the system parameters.
TABLE 5-1. Discrete Input Function
Block System Parameters
OUT_D = The discrete output value and status
fieldbus-fbus_33a
DI
OUT_D
Parameters Units Description
BLOCK_ERR None The summary of active error conditions associated
with the block. The supported block errors in the
Discrete Input functionblock are Simulate active,Input
failure/process variable has
Bad status, and Out of
service. See System Support.
DISC_LIM None The state of the discrete input that causes an alarm.
Any number from 0 to 255 may be. State 255 specifies
that no alarm indication is to be shown.
FIELD_VAL_D None The value and status of the discrete input from a field
device.
CHANNEL None Defines the I/O input used for the field measurement.
IO_OPTS None Allows you to select options for I/O value processing.
The supported I/O option for the Discrete Input
function block is Invert. See System Support.