Integrate the meter with the control system
7.1.2
Configure
Lower Range Value
(LRV) and
Upper Range Value
(URV)
Display
OFF-LINE MAINT→OFF-LINE CONFG→IO→AO 1/2→4 mA
OFF-LINE MAINT→OFF-LINE CONFG→IO→AO 1/2→20 mA
ProLink II
ProLink→Configuration→Analog Output→Primary/Secondary Output→Lower Range Value
ProLink→Configuration→Analog Output→Primary/Secondary Output→Upper Range Value
Field Communicator
Configure→Manual Setup→Inputs/Outputs→mA Output X→mA Output Settings→PV/SV LRV
Configure→Manual Setup→Inputs/Outputs→mA Output X→mA Output Settings→PV/SV URV
The
Lower Range Value
(LRV) and
Upper Range Value
(URV) are used to scale the mA output, i.e., to define
the relationship between
mA Output Process Variable
and the mA output level. The mA output uses a
range of 4–20 mA or 0–20 mA to represent
mA Output Process Variable
. Between
LRV
and
URV
, the mA
output is linear with the process variable. If the process variable drops below
LRV
or rises above
URV
,
the transmitter posts an output saturation alarm.
Note
If you change
LRV
and
URV
from factory default values, and you later change
mA Output Process Variable
,
LRV
and
URV
will not be reset to the default values. For example, if you configure
mA Output Process Variable
as mass flow and change the
LRV
and
URV
for mass flow, then you configure
mA Output Process Variable
as
density, and finally you change
mA Output Process Variable
back to mass flow,
LRV
and
URV
for mass flow
are reset to the configured values.
Procedure
1.
Set
LRV
as desired.
LRV
is the value of
mA Output Process Variable
represented by an output of 0 or 4 mA. The default
value depends on the setting of
mA Output Process Variable
.
Enter
LRV
in the measurement units that are configured for
mA Output Process Variable
.
2.
Set
URV
as desired.
URV
is the value of
mA Output Process Variable
represented by an output of 20 mA. The default value
depends on the setting of
mA Output Process Variable
.
Enter
URV
in the measurement units that are configured for
mA Output Process Variable
.
Note
You can set
URV
below
LRV
. For example, you can set
URV
to
50
and
LRV
to
100
.
Default values for
Lower Range Value
(LRV) and
Upper Range Value
(URV)
Each option for
mA Output Process Variable
has its own
LRV
and
URV
. If you change the configuration of
mA
Output Process Variable
, the corresponding
LRV
and
URV
are loaded and used.
Default values for
LRV
and
URV
are shown in Table 7-2 .
120
Micro Motion 9739 MVD Transmitters