User guide

tira47e1 (2005-08) BPG402SPv1.cp 27
Instance 2 of the Analog Sensor Input Function Block describes the functionality of
the BA measuring part of the gauge.
In Instance 2, the same attributes as in Instance 1 are supported:
ID Name Structure Data type Bytes Access Store
19 Process Value
(PV)
Simple According to
Data Type value
(parameter 21)
- 0_XI
1/2_R
V
20 Status Simple UINT8 1 0_XI
1/2_R
V
21 Data Type Simple UINT8 1 2_R/W N
22 Data Units Simple UINT16 2 2_R/W N
23 Reading Valid Simple Boolean 1 1/2_R V
24 Full Scale Simple According to
Data Type value
(parameter 21)
- 1/2_R N
39 Safe State Simple UINT8 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 BA Device Instance in the
currently selected data unit (ID 22) and in the selected 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. After the gauge is switched
on, the value stored in the EEPROM is loaded. The data type setting can only be
modified when the gauge is in the IDLE status. By defining the configuration 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.
3.2.3 Analog Sensor Input
Function Block
SLOT 1 / Instance 2
3.2.3.1 Process Value ID 19
3.2.3.2 Status ID 20
3.2.3.3 Data Type ID 21