Endress+Hauser Smartec S CLD132, Руководство по эксплуатации

Страница: 17 / 44

Smartec S CLD132/134 PROFIBUS-PA/-DP System integration
Hauser 17
Rescaling the input value
In the Analog Input function block, the input value or input range can be scaled in
accordance with the automation requirements.
Example:
• The system unit in the Transducer Block is °C.
• The measuring range of the device is –10 to 150 °C.
• The output range to the automation system should be 14 °F to 302 °F.
• The measured value from the Transducer Block (input value) is rescaled linearly via the
input scaling PV_SCALE to the desired output range OUT_SCALE.
• Parameter group PV_SCALE
PV_SCALE_MIN (V1H0) –10
PV_SCALE_MAX (V1H1) 150
• Parameter group OUT_SCALE
OUT_SCALE_MIN (V1H3) 14
OUT_SCALE_MAX (V1H4) 302
OUT_UNIT (V1H5) [F]
The result is that with an input value of 25 °C, for example, a value of 77 °F is output via the
OUT parameter (

å
11).
a0005922-en
Fig. 11: Scaling the input value for the Analog Input function block
Limit values
You can set two warning limits and two alarm limits for monitoring your process. The status
of the measured value and the parameters of the limit-value alarms are indicative of the
measured value's relative position. You also have the option of defining an alarm hysteresis
in order to avoid frequent changes of the limit-value flags and frequent enabling/disabling
of alarms.
The limit values are based on the OUT output value. If the OUT output value exceeds or
undershoots the defined limit values, the automation system is alarmed via the limit value
process alarms (see below).
The following limit values can be defined:
– HI_LIM, HI_HI_LIM
– LO_LIM, LO_LO_LIM
Alarm detection and processing
Limit value process alarms are generated by the Analog Input function block. The status of
the limit value process alarms is communicated to the automation system by means of the
following parameters:
– HI_ALM, HI_HI_ALM
– LO_ALM, LO_LO_ALM
Transducer
Block
25 °C
-10
150
°C
77 °F
14
°F
302
OUT
PV_SCALE OUT_SCALE
0
0
100
100
%
tempe-
rature
Analog Input Function Block
–10 ... 150 °C
HAUSER
SMARTEC S HAUSER
SMARTEC S
ALARM
CAL
E
+
–