Emerson Rosemount 644 with HART Protocol Reference Manual page 27

Reference Manual
00809-0200-4728, Rev SA
LOI
To configure Hot Backup on the LOI, enable the mode and set the PV values. Reference
where to find these in the menu.
Figure 2-11. Configuring Hot Backup with LOI
VIEW CONFIG
SENSOR CONFIG
UNITS
RERANGE
LOOP TEST
DISPLAY
EXTENDED MENU EXTENDED MENU
EXIT MENU
* Available only if option code (S) or (D) is ordered.
** Available only if option codes (S) and (DC) are both ordered, or if option codes (D) and (DC) are both ordered.
For information on using Hot Backup in conjunction with the HART Tri-Loop
with the HART Tri-Loop" on page
2.7.4 Sensor drift alert configuration
The sensor drift alert command allows the transmitter to set a warning flag (through HART), or go into
analog alarm when the temperature difference between sensor 1 and sensor 2 exceeds a user-defined
limit.
This feature is useful when measuring the same process temperature with two sensors, ideally when
using a dual-element sensor. When sensor drift alert mode is enabled, the user sets the maximum
allowable difference, in engineering units, between sensor 1 and sensor 2. If this maximum difference is
exceeded, a sensor drift alert warning flag will be set.
Though it defaults to WARNING, when configuring the transmitter for sensor drift alert, the user also has
the option of specifying the analog output of the transmitter go into ALARM when sensor drifting is
detected.
Note
Using dual sensor configuration in the Rosemount 644 Transmitter, the transmitter supports the
configuration and simultaneous use of Hot Backup and sensor drift alert. If one sensor fails, the
transmitter switches output to use the remaining good sensor. Should the difference between the two
sensor readings exceed the configured threshold, the AO will go to alarm indicating the sensor drift
condition. The combination of sensor drift alert and Hot Backup improves sensor diagnostic coverage
while maintaining a high level of availability. Refer to the Rosemount 644 FMEDA report for the impact
on safety.
Configuration
CALIBRAT
DAMPING
VARIABLE MAP
TAG
ALM SAT VALUES
PASSWORD
SIMULATE
HART REV
HOT BACK CONFIG** HOT BACK CONFIG**
DRIFT ALERT**
....
35.
Configuration
July 2018
Figure 2-11
HOT BACK MODE
HOT BACK PV
HOT BACK RESET
BACK TO MENU
EXIT MENU
™
see "Using the transmitter
for
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