Reference Manual

00809-0100-4697, Rev EA October 2011

Rosemount 848T

Alarms

Damping

Configure the Differential Sensors

Configure Measurement Validation

Use the following steps to configure the alarms, which are located in the Resource Function Block.

1.Set the resource block to OOS.

2.Set WRITE_PRI to the appropriate alarm level (WRITE_PRI has a selectable range of priorities from 0 to 15, see “Alarm Priority Levels” on page 3-11.Set the other block alarm parameters at this time.

3.Set CONFIRM_TIME to the time, in 1/32 of a millisecond, that the device will wait for confirmation of receiving a report before trying again (the device does not retry if CONFIRM_TIME is 0).

4.Set LIM_NOTIFY to a value between zero and MAX_NOTIFY.

LIM_NOTIFY is the maximum number of alert reports allowed before the operator needs to acknowledge an alarm condition.

5.Enable the reports bit in FEATURES_SEL. (When Multi-bit alerts is enabled, every active alarm is visible for any of the eight sensors, generated by a PlantWeb alert. This is different than only viewing the highest priority alarm.)

6.Set the resource block to AUTO.

For modifying alarms on individual function blocks (AI or ISEL blocks), refer to Appendix D: Function Blocks.

Use the following steps to configure the damping, which is located in the Transducer Function Block.

1.Set Sensor Mode to Out of Service.

2.Change DAMPING to the desired filter rate (0.0 to 32.0 seconds).

3.Set Sensor Mode to In Service.

Use the following steps to configure the Differential Sensors:

1.Set Dual Sensor Mode to Out of Service.

2.Set Input A and Input B to the sensor values that are to be used in the differential equation diff = A–B. (NOTE: Unit types must be the same.)

3.Set the DUAL_SENSOR_CALC to either Not Used, Absolute, or INPUT A minus INPUT B.

4.Set Dual Sensor Mode to In Service.

Use the following steps to configure Measurement Validation:

1.Set mode to Disabled for specific sensor.

2.Select sample rate. 1-10 sec/sample is available. 1 second/sample is preferred for sensor degradation. The higher the number of seconds between samples, the more emphasis put on process variation.

3.Select Deviation Limit from 0 to 10 units. If deviation limit is exceeded, a status event will be triggered.

4.Select Increasing Limit. Sets the limit for increasing rate of change. If limit is exceeded, a status event will be triggered.

5.Select Decreasing Limit. Sets the limit for decreasing rate of change. If limit is exceeded, a status event will be triggered.

NOTE:

The decreasing limit selected is required to be a negative value.

3-3

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Emerson manual Rosemount 848T

848T specifications

The Emerson 848T is a state-of-the-art temperature transmitter designed for accurate and reliable temperature measurement in various industrial applications. This device has gained recognition for its advanced features and robust performance, making it a popular choice among engineers and technicians in the field.

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The device is designed with user-friendliness in mind. Its intuitive setup procedure and robust graphical user interface simplify the commissioning process, ensuring that even those new to the technology can easily navigate the system. An integrated LCD display provides real-time readings and status information, facilitating monitoring at a glance.

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