Flowserve MX/QX Profibus DP/PA Field Unit - Manual (Page 43)

43
PB DPV1 / PA Field Unit Installation and Maintenance FCD LMENIM2336-03 – 12/12
flowserve.com
Figure 3.4 – Analog Input Block Scaling and Filtering
Field_Val = (Channel_value – EU 0%) / (EU 100% - EU 0%)
PV_SCALE
Configuration
Parameters
PV = Field_Val * (EU 100% - EU 0%) + EU 0%
OUT_SCALE
Filter
OUT
Field_Val
PV_SCALE
OUT_SCALE
PV_FTIME
Transducer Block
Value, e.g., Position
FB-Algorithm
Filter
The function block parameter PV_FTIME (acyclic) contains the time constant in seconds of the rise
time of the FB output up to a value of 63.21% resulting from a jump on the input.
Fail-Safe
The parameter FSAFE_TYPE (acyclic) defines the reaction of the device if a fault is detected. The
calculated ACTUAL MODE remains AUTO.
Fail-Safe
0 Value FSAFE_VALUE is used as OUT.
1 Use of stored last valid OUT value.
2 OUT has the wrong calculated value and status.
FSAFE_VALUE (acyclic) is the default value for the OUT parameter, if a sensor electronic fault is
detected due to transducer block communication problems with actuator hardware. The unit of this
parameter is the same as OUT.
Channel
CHANNEL (acyclic) is the reference to the active transducer block which provides the measurement
value to the function block.
Alarms (Acyclic)
• ALARM_HYS (Hysteresis) – If the process variable fluctuates around the Hi or Low limit values, it
will generate many limit violations. It is therefore possible to trigger alarm only after crossing an
adjustable hysteresis.
• HI_ALM, HI_HI_ALM, LO_ALM, and LO_LO_ALM – When the measured variable reaches or
crosses these points, a time of day stamp is specified with these alarm parameters.