INFICON PSG55x ATM to Medium Vacuum Gauge (Profibus) - Manual (Page 36)

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tira56e1 (2010-02) PxG55x.cp
The device supports the four data units described below:
Coding (hex) Unit
1001 COUNTS
1301 Torr
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.
→  12 "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. This
means that the following conditions are fulfilled:
• The gauge is in the EXECUTING status (Device Block, ID 25)
• The exception status contains no manufacturer warning or alarm
• The transducer block contains no sensor alarm (ID 103)
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 the Status Extension (ID 102,
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 measurement scale of the device in
terms of the currently selected data type (ID 21) and data unit (ID 22).
When the gauge is not in the EXECUTING status (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 the following Safe State values:
Option Coding ProcessValue (PV) behavior
Zero 0 The PV is set to 0.
Full Scale 1 The PV is set to the full scale value (ID 24).
Hold Last Value 2 The PV is set to the last valid value obtained in
the EXECUTING status.
Use Safe Value 3 The PV is set to the Safe Value (ID 40).
The Safe Value is the value output with the Process Value Parameter (ID 19) when
an error occurs or the gauge goes to the NOT EXECUTING status. If this value is
set to zero, it will remain on zero when the data unit is changed.
This parameter defines, if the CDG Zero pressure is automatically and periodically
calibrated.
This parameter contains the highest valid Process Value (PV) of the device in
terms of the currently selected data type (ID 21) and data unit (ID 22).
This parameter contains the lowest valid Process Value (PV) of the device in terms
of the currently selected data type (ID 21) and data unit (ID 22).
8.1.6 Data Unit (ID 22)
8.1.7 Reading Valid (ID 23)
8.1.8 Full Scale (ID 24)
8.1.9 Safe State (ID 39)
8.1.10 Safe Value (ID 40)
8.1.11 Auto Zero Enable
(ID 41)
8.1.12 Overrange (ID 44)
8.1.13 Underrange (ID 45)