INFICON PSG55x ATM to Medium Vacuum Gauge (DeviceNet) - Manual (Page 31)

tira58e1-a (2012-03) PxG5xx.cp
31
All Data Type attributes use the enumerated values integer or float.
The Data Type value will be set automatically based upon the first valid I/O con-
nection established by the device.
If no established I/O connections exist, which include an attribute from this object,
then the Data Type attribute is settable provided that the object is in the Idle State.
If the data type is set to integer and the data unit is chosen with Counts a
pressure level can be calculated back with (e.g. in mbar):
16
int eger
mbar
Value
P
=
Using data type integer in combination with a pressure unit (mbar, Torr
or Pa) will obviously not produce reasonable values below 1.
The output of the data type "float" in combination with the data unit
"Counts" is in a fixpoint format with 1 bit for the sign, 11 bits for the
integer and 20 bits for the decimal part. To convert it into a normal float
format the output has to be divided by 2
20 .
→ Instance 1
→ Instance 1
→ Instance 1
→ Instance 1
16 bits are used as sensor warnings.
Data component Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Sensor warning byte 0 0 0 0 0 0 0 0 0
Sensor warning byte 1 0 0 0 0 0 0 0 0
16 bits are used as sensor faults.
Data component Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Sensor alarm byte 0 0 0 0 0 0 0 0 Diaphragm
Failure
Sensor alarm byte 1 0 0 0 0 0 0 0 0
8 bits providing the current sensor alarm state of the instance
Data component Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Sensor alarm byte 0 0 0 0 0 0 Underrange
exceeded
Overrange
exceeded
Reading
invalid
1)
1) Logical inversion of reading valid
The S-Analog sensor object provides the following common services:
Service
code
Service name Description of service
0E
h
Get_Attribute_Single Returns the contents of the specified attribute.
10
h
Set_Attribute_Single Modifies an attribute value.
4.4.3.11 Semantics of S-Analog
Sensor Instance 3
Data type
Data units
Value
Safe state
Safe value
Sensor warning
Sensor alarm
Status extension
4.4.3.12 Common Services of
S-Analog Sensor
Instance 2