INFICON BCG450-SD ATM to Ultra-High Vacuum Triple Gauge (DeviceNet) - Manual (Page 19)

tira40e1 (2005-04) BCG450SDv1.cp
19
An S-Analog Sensor object instance derives a reading from a physical analog sen-
sor. The reading is converted to the data type and units specified for the Value
attribute.
Using Counts and INT the following conversion has to be used:
Counts = [ log
10
(pressure) + k ] × 2000
where: k
mbar
= 12.5
k
Torr
= 12.624903
k
Pa
= 10.5
This attribute specifies what value will be held in Value for states other than Exe-
cuting. The purpose of this mechanism is to allow other devices, who may be using
this Value to transition to (or remain in) a safe state in the event of this device
transitioning to a FAULT, IDLE, or ABORT state. The following values are defined:
Attribute Value State
0 Zero
1 Full Scale
2 Hold Last Value
3 Use Safe Value
For Safe State set to Use Safe Value, this attribute holds the value to which the
Value attribute will be set for object instance states other than Executing.
16 Bits are used as Sensor faults. Sensor Alarm Byte 1 is mapped to the Device
Exception Detail Alarm 3, Sensor Alarm Byte 0 is mapped to the Device Exception
Detail Alarm 2.
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 0
Sensor Alarm Byte 1
0 0 0 0 0 0
Electronics
Failure
0
16 Bits are used as Sensor Warnings. Sensor Warning Byte 0 is mapped to the
Device Exception Detail Warning 3, Sensor Warning Byte 0 is mapped to the
Device Exception Detail Warning 4.
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
Electronics
Warning
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
Value
Safe State
Safe Value
Sensor Alarm
Sensor Warning
Status Extension