Flowserve MX/QX Profibus DP/PA Field Unit - Manual (Page 48)

PB DPV1 / PA Field Unit Installation and Maintenance FCD LMENIM2336-03 – 12/12
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3.5 Discrete Input (DI) Function Block
The Discrete Input (DI) function block can process one of several possible process parameters in
the actuator and make it available to the network user. The DI block supports signal inversion, mode
control, signal status propagation, and simulation.
There are four DI blocks in the MX/QX actuator device, and seven channels. Each of these DI function
blocks can be assigned to any one of the following channels:
Channel Channel Name Description
347 DI_POSITION_AND_BUS_MODE_CHAN Valve status and control mode
348 DI_POSITION_CHAN Valve status, moving/stopped
349 DI_ACTUATOR_FAULTS_1_CHAN Mechanical and electrical faults 1
350 DI_ACTUATOR_FAULTS_2_CHAN Mechanical and electrical faults 2
351 DI_ACTUATOR_ALARMS_CHAN Emergency shutdown and inhibits
352 DI_DISC_USER_INPUT_CHAN Discrete input from user
353 DI_READ_DISC_OUTPUT_CHAN Read discrete output
Normally the block is used in Automatic Mode so that the Process Variable is copied to the Output.
If necessary, the operator can change the mode to Manual, which disconnects the field signal and
substitutes a manually entered value for the Output.
Inputs
The discrete input data comes from the transducer block, as selected by the CHANNEL (acyclic)
parameter.
Outputs
OUT_D (cyclic) is the block discrete output and represents the process data obtained from the
actuator hardware.
The INVERT (acyclic) option can be used to do a Boolean NOT function between the field value and
the output. It indicates whether the input value of PV_D should be logically inverted before it is stored
in the OUT_D parameter.
List of valid values:
INVERT
0 Not inverted
1 Invert
Fail-Safe
The FSAFE_TYPE (acyclic) parameter defines the reaction of the device, if a fault is detected.
FSAFE_TYPE
0
Value FSAFE_VALUE_D is used as OUT_D.
Status – UNCERTAIN_Initial Value.
1
Use of stored last valid OUT_D value.
Status – UNCERTAIN_LastUsableValue; if there is no valid value available, then
UNCERTAIN_Initial_Value.
2 OUT_D has the wrong calculation value and status.