Rosemount 8712, Reference Manual

Page: 135 / 212

Reference Manual
00809-0100-4664, Rev BA
January 2010
C-3
Rosemount 8712
Tunable Empty Pipe
Parameters
The Tunable Empty Pipe diagnostic has one read-only parameter, and two
parameters that can be custom configured to optimize the diagnostic
performance.
Empty Pipe Value
Reads the current Empty Pipe Value. This is a read-only value. This number
is a unitless number and is calculated based on multiple installation and
process variables such as sensor type, line size, process fluid properties, and
wiring. If the Empty Pipe Value exceeds the Empty Pipe Trigger Level for a
specified number of updates, then the Empty Pipe diagnostic alert will
activate.
Empty Pipe Trigger Level
Limits: 3 to 2000
This value configures the threshold limit that the Empty Pipe Value must
exceed before the Empty Pipe diagnostic alert activates. The default setting
from the factory is 100.
Empty Pipe Counts
Limits: 5 to 50
This value configures the number of consecutive updates that the Empty Pipe
Value must exceed the Empty Pipe Trigger Level before the Empty Pipe
diagnostic alert activates. The default setting from the factory is 5.
Optimizing Tunable
Empty Pipe
The Tunable Empty Pipe diagnostic is set at the factory to properly diagnose
most applications. If this diagnostic unexpectedly activates, the following
procedure can be followed to optimize the Empty Pipe diagnostic for the
application.
1. Record the Empty Pipe Value with a full pipe condition.
Example
Full reading = 0.2
2. Record the Empty Pipe Value with an empty pipe condition.
Example
Empty reading = 80.0
3. Set the Empty Pipe Trigger Level to a value between the full and
empty readings. For increased sensitivity to empty pipe conditions,
set the trigger level to a value closer to the full pipe value.
Example
Set the trigger level to 25.0
4. Set the Empty Pipe Counts to a value corresponding to the desired
sensitivity level for the diagnostic. For applications with entrained air
or potential air slugs, less sensitivity may be desired.
HART Fast Keys 1, 2, 2, 4, 1
LOI Key XMTR INFO
AMS Tab Diagnostics
HART Fast Keys 1, 2, 2, 4, 2
LOI Key AUX. FUNCTION
AMS Tab Diagnostics
HART Fast Keys 1, 2, 2, 4, 3
LOI Key AUX. FUNCTION
AMS Tab Diagnostics