Siemens LR 460 Manuale Utente
Page J-102
SITRANS LR 460 (PROFIBUS PA) – INSTRUCTION MANUAL
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Electronics temperature
The Level Transducer Block also monitors the internal temperature of the device
electronics. If the temperature exceeds permitted limits, it does not change the sensor
value, but it does change the status.The permitted limits correspond to those of the
permitted ambient temperature.
electronics. If the temperature exceeds permitted limits, it does not change the sensor
value, but it does change the status.The permitted limits correspond to those of the
permitted ambient temperature.
If a temperature limit is exceeded, the status changes. Peak indicators
1
allow you to
check the maximum and minimum temperatures that have occurred.
Analog Input Function Blocks 1 and 2
There are two identical Analog Input Function Blocks which operate independently. The
figure below shows how measured values are processed within the Analog Input
Function Block (AIFB1 or AIFB2) to produce the device output, which is communicated via
cyclic transfer to PROFIBUS PA, and displayed on the LCD.
figure below shows how measured values are processed within the Analog Input
Function Block (AIFB1 or AIFB2) to produce the device output, which is communicated via
cyclic transfer to PROFIBUS PA, and displayed on the LCD.
Analog Input Function Block function groups (simulation, mode and status)
2
How the AIFBs work
The Analog Input Function Blocks allow you to control modifications to the output value
(PROFIBUS cyclic data).
(PROFIBUS cyclic data).
1.
Open View menu, scroll down to Peak Values, and click on Temperature tab in the
Peak Values window.
Peak Values window.
2.
The output from the Level Transducer Block can be called the Primary Value (or
Secondary Value). When it becomes the input to the AIFB, it is called the Process
Variable.
Secondary Value). When it becomes the input to the AIFB, it is called the Process
Variable.
enable
on
FB
algorithm
Status
OUT
AUTO
MODE and
STATUS
handling
Process Variable
from TB
(Function Block
input)
Value Status
Alarm
Limit
Check
Out of
Service
OUT
MAN
Value
simulate
value and
status
Value Status
Operator
Operator
off
Simulate
Parameter
Fail-safe
no
output