Reference Manual
748384-C
September 2003
Rosemount Analytical Inc. A Division of Emerson Process Management I/O Modules Variables
3-19
NGA2000 Reference
PVIA
Direction Input
Binding
PVA
Type Floating
point
Value range
0 - 1,000,000 typically, no hard limits though.
Units ppm
Description
The primary variable input- the main gas measurement from the analyzer. In the
SCAL this is the input for subnode 1.
Usage
PVA is the main reading from the analyzer. It is bound to the input variable PVIA
in the 1/0 modules. PVA is always transmitted in units of ppm. It is generated by a
complicated algorithm described in other documents. Its output update rate may
be controlled by LONPVUPDATE. It can be delayed in time in order to align the
outputs from multiple analyzers all looking at the same sample gas, using
AMDELAYTIME. Its response time can be controlled (within the physical limits of
the measurement) by AFT90_. If the analyzer considers that its reading is invalid
for some reason, PVA is still reported but the variable VALIDITY is set to invalid.
If the analyzer is in a mode other than normal, the variable OPSTATUS will be set
to some value other than zero, but again PVA is still reported. This is true even of
analyzers that cannot perform a measurement, such as a FID with no flame.
See also
VALIDITY
OPSTATUS
PVACEMS
PVIB
PVIC
PVID
PVIB
Direction Input
Binding
PVA
Type
Floating point
Value range
0 - 1,000,000 typically, no hard limits though.
Units ppm
Description
SCAL only; The primary variable input- the main gas measurement from the
analyzer 2.
Usage
Equivalent to PVIA for subnode 2, bound to analyzer 2 in the SCAL.
See also
VALIDITY
OPSTATUS
PVACEMS
PVIA
PVIC
PVID
