Emerson NGA2000 Reference Manual page 140

Reference Manual
748384-C
September 2003
GAS_SELECT
Direction
Binding
Type
Value range
Units
Description
Usage
See also
GENPARMA
Direction
Binding
Type
Value range
Units
Description
Usage
See also
GENPARMB
Direction
Binding
Type
Value range
Units
Description
Usage
See also
3-14 I/O Modules Variables
Output
None
3-element enumerated array
Sample; SPAN 1; SPAN 2; SPAN 3; SPAN 4; ZERO.
None
ACAL, SCAL only; selects or shows a particular gas.
The current gas selected by the calibration algorithm.
The gas that the user wants to have selected by the manual calibration algorithm.
The gas selected for a solenoid valve test in the diagnostic menus.
These are used in various places in the menu system. Element 1 shows the user
what is happening, element 2 is used by the user to control the manual calibration,
and element 3 is used by the user to directly control the operation of an output
relay (and thus presumably the gas controlled by that relay).
Output
None
Enumerated
Percent; Absolute
None
Determines whether any concentration alarm responds to an absolute value or a
percent of the current range.
If set to "Percent' ', any concentration alarm will respond to ALLVL element 2, 4 or
6, where the value in that variable is multiplied (as a percentage) with RNGHI for
the current range. If set to "Absolute", any concentration alarm will respond to
ALLVL element 1, 3 or 5, directly comparing PVA against this value.
ALLVL
output
None
Enumerated
0;1;2;5;10;15;20;30
Percent
AIO only; determines the hysteresis in the concentration alarm setting.
If the alarm set point is set to 100, and it is a high alarm, the relay will chance state
as the concentration level (PVA) reaches 100. If the concentration then drops back
again, it will have to drop by the percentage given in this variable before the relay
changes state again.
ALLVL
RNGHI
NGA2000 Reference
Rosemount Analytical Inc. A Division of Emerson Process Management