Agilent Technologies TwisTorr 304 FS AG Notice De Mode D'emploi page 226

17 Technical Information
Programmable Analog Output Diagrams
When in programmable analog signal you read a voltage below
the voltage range (in above table) it means "Error Over range", if
you read a voltage below the voltage range it means "Error
Under range" (in these cases you can read the manual of the
gauge for further details).
With the serial communication you can use the following
windows:
Win 224
Win 257
Win 267
The windows from 136 to 140 manage an additional set point
(set point 3) dedicated to turn ON or OFF the gauge (win 267=4)
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Pressure reading with the format X.X E XX
Gauge status (read only):
0  when a gauge is not connected
1  when a gauge is connected
2  when the pressure read is under
3  when the pressure read is under
4  when the "identification" is present
Gauge power (read/write):
If you need to turn off the gauge at
certain condition you can use this
window
0  gauge off
1  gauge on (default)
2  gauge normally off. It turns on when
the set point 1 is activated. If the set
point 1 type (win 101) is selected as
"pressure" the gauge is always on.
3  gauge normally off. It turns on when
the set point 1 is activated. If the set
point 2 type (win 171) is selected as
"pressure" the gauge is always on.
4  gauge normally off. It turns on when
the set point 1 is activated. If the set
point 3 type (win 101) is selected as
"pressure" the gauge is always on.
TwisTorr 304 FS AG Rack Controller User Manual / 87-901-029-01 (E)
range or when the gauge give an
internal error
range or when the gauge give an
internal error
but not known by the controller