INFICON BCG450-SP ATM to Ultra-High Vacuum Triple Gauge (Profibus) - Manual (Page 28)

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tira41e1 (2005-06) BCG450SPv1.cp
The gauge supports the following pressure units:
Coding Pressure unit
1001 COUNTS
1301 Torr
1302 mTorr (Micron)
1308 mbar
1309 Pascal
For safety reasons, it is not possible to change the pressure unit while
the gauge is cyclically interchanging data with a DP/V0 master.
The data unit setting can only be modified when the gauge is in the IDLE
status.
In cyclic data traffic, the data unit must be set in the User Parameter
Data. All settings previously made in acyclic data traffic are overwritten
(
→ section "User Parameter Data").
If the data unit is set in one instance, that data unit setting applies to all
instances. Likewise, the data unit setting made in the User Parameter
Data is valid for all instances.
This parameter indicates that the pressure reading is within a valid range, which
means that:
• The gauge is in the EXECUTING status.
• There is no error (ID 26 or 27 of the Device Block)
• The measured value is lower than the overrange value and higher than the
underrange value.
If this value is set to zero, the pressure reading is not valid. In such a
case, either check Exception Status (ID 26, Device Block) to find out
whether there is an error or check One Of N Status Extension (ID 120,
One Of N Vacuum Gauge Transducer Block) to find out whether the
measured value is out of the specified measuring range (overrange or
underrange mode).
This parameter contains the valid maximum value of the pressure reading
(1000 mbar) in the currently selected data unit and data type.
Pressure unit Full scale
COUNTS 21602
Torr 1.5×10
-2
mTorr (Micron) 15
mbar 2×10
-2
Pascal 2
When the gauge is not in the EXECUTING state (ID 25, Device Block) or if there is
a device error, a value defined by Safe State is output as pressure value. You can
select among:
• "0"
• Full scale
• Last valid value
• Safe Value (user-definable in ID 40)
3.2.3.4 Data Unit
3.2.3.5 Reading Valid
3.2.3.6 Full Scale
3.2.3.7 Safe State