Reference Manual

00809-0100-4697, Rev EA October 2011

Rosemount 848T

Indirect Square Root

Indirect Square Root signal conversion takes the square root of the value computed with the indirect signal conversion and scales it to the range and units of the PV and OUT parameters.

PV =

FIELD_VAL

× (EU**@100% EU**@0%) + EU**@0%

------------------------------100

 

 

** OUT_SCALE values

When the converted input value is below the limit specified by the LOW_CUT parameter, and the Low Cutoff I/O option (IO_OPTS) is enabled (True), a value of zero is used for the converted value (PV). This option eliminates false readings when the differential pressure measurement is close to zero and it may be useful with zero-based measurement devices such as flowmeters.

NOTE

Low Cutoff is the only I/O option supported by the AI block. Set the I/O option when the block is OOS.

Block Errors

Table D-2lists conditions reported in the BLOCK_ERR parameter. Conditions in bold are inactive for the AI block and are given here for reference.

Table D-2. BLOCK_ERR

Conditions

Number

Name and Description

 

0

Other

 

1

Block Configuration Error: the selected channel carries a measurement that is

 

 

incompatible with the engineering units selected in XD_SCALE, the L_TYPE

 

 

parameter is not configured, or CHANNEL = zero.

 

2

Link Configuration Error

 

3

Simulate Active: Simulation is enabled and the block is using a simulated value in

 

 

its execution.

 

4

Local Override

 

5

Device Fault State Set

 

6

Device Needs Maintenance Soon

 

7

Input Failure/Process Variable has Bad Status: The hardware is bad, or a bad

 

 

status is being simulated.

 

8

Output Failure: The output is bad based primarily upon a bad input.

 

9

Memory Failure

 

10

Lost Static Data

 

11

Lost NV Data

 

12

Readback Check Failed

 

13

Device Needs Maintenance Now

 

14

Power Up

 

15

Out of Service: The actual mode is out of service.

D-5

Page 95
Image 95
Emerson 848T manual Indirect Square Root, Conditions

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.