Emerson Rosemount 644h, Справочное руководство

Страница: 36 / 78

Reference Manual
00809-0100-4728, Rev HA
December 2002
Models 644H and 644R
3-10
After completing the test procedure, the display returns to the loop test screen
and another output value can be chosen.
Master Reset
Master Reset resets the electronics without actually powering down the unit. It
does not return the transmitter to the original factory configuration.
Active Calibrator
The Active Calibrator Mode command enables or disables the pulsating
current feature. The transmitter ordinarily operates with pulsating current so
that sensor diagnostic functions, such as open sensor detection and EMF
compensation, can be performed correctly. Some calibration equipment
requires steady current to function properly. By enabling the Active Calibrator
Mode the transmitter stops sending pulsating current to the sensor and
supples a steady current. Disabling the Active Calibrator returns the
transmitter to its normal operating state of sending a pulsating current to the
sensor, thus enabling the sensor diagnostic functions.
The Active Calibrator Mode is volatile and will be automatically disabled when
power is cycled or when a Master Reset is performed using the Model 275
HART Communicator.
NOTE
The Active Calibrator Mode must be disabled before returning the transmitter
to the process. This will ensure that the full diagnostic capabilities of the
Model 644 are available.
Disabling or enabling the Active Calibrator Mode will not change any of the
sensor trim values stored in the transmitter.
Sensor Review
The Signal Condition command allows viewing or changing the primary
variable lower and upper range values, sensor percent of range, and sensor
damping.
Write Protect
The Write Protect command allows you to protect the transmitter
configuration data from accidental or unwarranted changes. To enable the
write protect feature, perform the following procedure:
1. From the
HOME
screen select 1 Device Setup , 2 Diag/Service ,
3 Write Protect.
2. Select Enable WP.
NOTE
To disable write protect on the Model 644, repeat the procedure, replacing
Enable WP with Disable WP .
Fast Key Sequence 1, 2, 1, 3
Fast Key Sequence 1, 2, 2, 1, 3
Fast Key Sequence 1, 4, 2
Fast Key Sequence 1, 2, 3