INFICON BCG450-SP ATM to Ultra-High Vacuum Triple Gauge (Profibus) - Manual (Page 30)

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tira41e1 (2005-06) BCG450SPv1.cp
Instance 3 of the Analog Sensor Input Function Block describes the functionality of
the Capacitance diaphragm sensor measuring part of the gauge.
In Instance 3, the same attributes as in Instance 1 are supported:
ID Name Structure Data type Bytes Access Store
19 Process Value
(PV) Simple According to
Parameter Data
Type - 0_XI
1_R
2_R D
20 Status Simple Unsigned8 1 0_XI
1/2_R D
21 Data Type Simple Unsigned8 1 2_R/W N
22 Data Units Simple Unsigned16 2 2_R/W N
23 Reading Valid Simple Boolean 1 1_R
2_R D
24 Full Scale Simple According to
Data Type value
(parameter 21) - 1/2_R N
39 Safe State Simple Unsigned8 1 1/2_R/W N
40 Safe Value Simple According to
Data Type value
(parameter 21) - 1/2_R/W N
44 Overrange Simple According to
Data Type value
(parameter 21) - 1/2_R N
45 Underrange Simple According to
Data Type value
(parameter 21) - 1/2_R N
The Process Value contains the measured value of the Capacitance diaphragm
sensor Device Instance in the currently selected data unit (ID 22) and in the se-
lected data type (ID 21).
If the device is not in the EXECUTING status (ID 25, Device Block), the value
defined in the Safe State is output.
Values output in the data unit COUNTS can be converted into a pressure value by
means of the following formulas:
Calculation of the pressure (PV is the abbreviation used for Process Value):
PV
mbar
= 10
(COUNTS / 2000) - 12.5
PV
Torr
= 0.75006168 × PV
mbar
PV
Micron
= 10
-3
× PV
Torr
PV
Pa
= 100 × PV
mbar
This parameter is remains on "0".
Two data types are supported: Float and Integer16.
In cyclic data traffic, the data type cannot be modified. The data type setting can
only be modified when the gauge is in the IDLE status. By defining the configura-
tion data for cyclic data traffic (selection of standard telegram), the data type used
in the selected standard telegram is taken over. All settings previously made in
acyclic data traffic are thus overwritten.
3.2.4 Analog Sensor Input
Function Block
Instance 3 / SLOT 1
3.2.4.1 Process Value
3.2.4.2 Status
3.2.4.3 Data Type