Instruction Manual

Instruction Manual
D103434X012
Blocks
November 2014
105
Modes
The Discrete Input function block supports the following modes:
D Manual (Man)—The block output (OUT_D [8]) is disconnected from the field and set manually.
D Automatic (Auto)—The block algorithm determines output.
D Out of Service (OOS)—The block is not processed. The OUT_D [8] status is set to Bad: Out of Service. The
BLOCK_ERR [6] parameter shows Out of Service.
Block Initialization
The Fieldbus Foundation specification requires that certain parameters in the function blocks have initial values of
uninitialized. In addition to setting the Resource block mode to AUTO, the control system or the user must change
those parameters from their uninitialized value to a valid value in order for the function block to move from the Out of
Service mode. For the DI function block, the CHANNEL [15] parameter must be initialized.
Status Handling
Under normal conditions, a Good: Non‐Cascade status is passed through to OUT_D [8]. The block also supports the
Status Action On Failure and BLOCK_ERR [6] indications.
When SIMULATE_D [9] is enabled, FIELD_VAL_D [7], PV_D [7], and OUT_D [8] change to the simulated status. When
the block is set to Manual mode, OUT_D [7] is set to Good: Non‐cascade, Constant status.
I/O Selection
To select the I/O associated with the discrete measurement, configure the value of the CHANNEL [15] parameter.
There are two channels associated with the DI function block in the digital level controller
D DI_1 (OUT)
D DI_2 (OUT)
The CHANNEL [15] parameter for the two DI blocks available in the digital level controller may be set independently to
achieve the desired level position detection. The channels are selectable for rising and/or falling trigger points, as
shown in figure B‐9. The DI block CHANNEL [15] definitions are listed in table B‐18. Refer to the following descriptions
for details of the operation of these channels.