Reference Manual

00809-0100-4697, Rev EA October 2011

Rosemount 848T

INPUT SELECTOR FUNCTION BLOCK

The Input Selector (ISEL) function block can be used to select the first good, Hot Backup, maximum, minimum, or average of as many as eight input values and place it at the output. The block supports signal status propagation. There is process alarm detection in the Input Selector function

IN_1

IN_2

IN_3

IN_4

IN_5

IN_6

IN_7

IN_8 DISABLE_1 DISABLE_2 DISABLE_3 DISABLE_4 DISABLE_5 DISABLE_6 DISABLE_7 DISABLE_8

OP_SELECT

OUT

OUT_D

SELECTED

ISEL

block. Table D-6lists the ISEL block parameters and their descriptions, units of measure, and index numbers. The block execution time is 30 ms.

IN (1-8) = Input

DISABLE (1-8) = Discrete input used to disable the associated input channel

SELECTED = The selected channel number

OUT = The block output and status

OUT_D = Discrete output that signals a selected alarm condition

Table D-6. Input Selector Function Block Parameters

Number

Parameter

Units

Description

1

ST_REV

None

The revision level of the static data associated with the input selector block. The

 

 

 

revision value will be incremented each time a static parameter value in the block

 

 

 

is changed.

2

TAG_DESC

None

The user description of the intended application of the block.

3

STRATEGY

None

The strategy field can be used to identify groupings of blocks. This data is not checked

 

 

 

or processed by the block.

4

ALERT_KEY

None

The identification number of the plant unit. This information may be used in the host for

 

 

 

sorting alarms, etc.

5

MODE_BLK

None

The actual, target, permitted, and normal modes of the block.

 

 

 

Actual: The mode the “block is currently in”

 

 

 

Target: The mode to “go to”

 

 

 

Permitted: Allowed modes that target may take on

 

 

 

Normal: Most common mode for target

6

BLOCK_ERR

None

This parameter reflects the error status associated with the hardware or software

 

 

 

components associated with a block. It is a bit string, so that multiple errors may

 

 

 

be shown.

7

OUT

OUT_RANGE

The primary analog value calculated as a result of executing the function block.

8

OUT_RANGE

EU of OUT

The engineering units code to be used in displaying the OUT parameter and

 

 

 

parameters which have the same scaling as OUT.

9

GRANT_DENY

None

Options for controlling access of host computers and local control panels to operating,

 

 

 

tuning, and alarm parameters of the block. Not used by device.

10

STATUS_OPTS

None

Allows the user to select options for status handling and processing.

11,1 2, 13,

IN_(1, 2, 3, 4, 5,

Determined by

A connection input from another block

14, 25, 26,

6, 7, 8)

source

 

27, 28

 

 

 

D-15

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Image 105
Emerson 848T manual Table D-6. Input Selector Function Block Parameters, IN1 IN2 IN3 IN4 IN5 IN6 IN7, OUT Outrange

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.