Reference Manual

00809-0100-4697, Rev EA October 2011

Rosemount 848T

Monitoring Application with a Single Selection

Example: Average exhaust temperature of gas and turbine where there is a single alarm level for all inputs.

 

Out_1

 

IN_1

 

 

Out

 

 

 

 

 

 

 

 

Out_2

 

IN_2

 

 

Out_D

 

 

 

 

 

 

 

 

 

Out_3

 

IN_3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Out_4

 

IN_4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Out_5

 

IN_5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MAI

Out_6

 

IN_6

 

 

ISEL

 

 

 

 

 

Out_7

 

IN_7

 

 

 

 

 

Function

 

 

 

Function

 

 

 

 

 

Block

Out_8

 

IN_8

 

 

Block

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.Link the MAI outputs to the ISEL inputs.

2.Place the Multiple Analog Input (MAI) function block in OOS mode (set MODE_BLK.TARGET to OOS).

3.Set CHANNEL= “channels 1 to 8.” Although the CHANNEL_X parameters remain writable, CHANNEL_X can only be set = X when CHANNEL=1.

4.Set L_TYPE to direct or indirect.

5.Set XD_SCALE (transducer measurement scaling) to the appropriate upper and lower range values, the appropriate sensor units, and display decimal point.

6.Set OUT_SCALE (MAI output scaling) to the appropriate upper and lower range values, the appropriate sensor units, and display decimal point.

7.Place the MAI function block in auto mode.

8.Place the Input Selector (ISEL) function block in OOS mode by setting MODE_BLK.TARGET to OOS.

9.Set OUT_RANGE to match the OUT_SCALE in the MAI block.

10.Set SELECT_TYPE to the desired function (Maximum Value, Minimum Value, First Good Value, Midpoint Value, or Average Value).

11.Set the alarm limits and parameters if necessary.

12.Place the ISEL function block in auto mode.

13.Verify that the function blocks are scheduled.

Measuring Temperature Points Individually

AI

 

Out

 

 

 

Function

Out_D

Block 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AI

 

Out

 

 

 

Function

Out_D

Block 8

Example: Miscellaneous monitoring of temperature in a “close proximity” where each channel can have different sensor inputs with different units and there are independent alarm levels for each input.

1.Place the first Analog Input (AI) function block in OOS mode (set MODE_BLK.TARGET to OOS).

2.Set CHANNEL to the appropriate channel value. Refer to “Alarm Priority Levels” on page 3-11for a listing of channel definitions.

3.Set L_TYPE to direct.

4.Set XD_SCALE (transducer measurement scaling) to the appropriate upper and lower range values, the appropriate sensor units, and display decimal point.

5.Set OUT_SCALE (AI output scaling) to the appropriate upper and lower range values, the appropriate sensor units, and display decimal point.

6.Set the alarm limits and parameters if necessary.

7.Place the AI function block in auto mode.

8.Repeat steps 1 through 7 for each AI function block.

9.Verify that the function blocks are scheduled.

3-5

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Emerson 848T manual Monitoring Application with a Single Selection, Measuring Temperature Points Individually
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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.

One of the key highlights of the Emerson 848T is its unique dual-channel capability, which allows it to seamlessly monitor two temperature sources simultaneously. This functionality is particularly beneficial in processes where multiple temperature points need to be assessed, optimizing efficiency and reducing the need for additional equipment. It supports various sensor types, including thermocouples, RTDs, and resistance temperature detectors, making it versatile for different applications.

The 848T is equipped with sophisticated digital processing technology, which enhances its accuracy and stability. It features a 24-bit analog-to-digital converter, ensuring precise measurement and minimizing drift over time. Moreover, the device boasts a wide operating temperature range, accommodating ambient conditions from -40°C to 85°C. This durability makes it suitable for harsh environments commonly encountered in industries such as oil and gas, pharmaceuticals, and power generation.

Another significant characteristic of the Emerson 848T is its configurable output options. Users can choose from a range of output signals, including 4-20 mA, which provides a standard interface for integration into existing control systems. Additionally, it offers a HART communication protocol, allowing for easy configuration, calibration, and diagnostics through a digital interface. This feature enhances the transmitter's usability, enabling operators to perform adjustments without direct access to the device.

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.

In summary, the Emerson 848T temperature transmitter combines reliable performance, user-friendly design, and advanced digital technologies. Its dual-channel capability, wide sensor compatibility, and adjustable output options make it an essential tool for achieving precise temperature measurements in various industrial settings. With these compelling features, the Emerson 848T stands out as a leading choice for professionals seeking accuracy and efficiency in their temperature monitoring applications.
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