Object Structure
20
17200138_002_C0 – (2016-10) –
Leybold
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 warnings. Bits 8 … 16 are mapped to the Exception
Detail Warning 2, Bits 0 … 7 are mapped to the Device Exception Detail
Warning 1.
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
Warning
0
16 Bits are used as sensor faults. Bits 8
…
16 are mapped to the Exception Detail
Alarm 1, Bits 0
…
7 are mapped to the Device Exception Detail Alarm 0.
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
ID 6
Value
ID 25
Safe State
ID 26
Safe Value
ID 94
Sensor Warning
ID 95
Sensor Alarm
