Rosemount 848T

Reference Manual

00809-0100-4697, Rev EA October 2011

TROUBLESHOOTING

FOUNDATION fieldbus

Symptom

Possible Cause

Corrective Action

Device does not show

Network configuration parameters

Set the network parameters of the LAS (host system) according to the FF

up in the live list

are incorrect

Communications Profile

 

 

ST: 8

 

 

MRD: 4

 

 

DLPDU PhLO: 4

 

 

MID: 7

 

 

TSC: 4 (1 ms)

 

 

T1: 96000 (3 seconds)

 

 

T2: 9600000 (300 seconds)

 

 

T3: 480000 (15 seconds)

 

Network address is not in polled

Set first Unpolled Node and Number of UnPolled Nodes so that the device

 

range

address is within range

 

Power to the device is below the

Increase the power to at least 9V

 

9 VDC minimum

 

 

Noise on the power /

Verify terminators and power conditioners are within specification

 

communication is too high

Verify that the shield is properly terminated and not grounded at both ends. It is

 

 

best to ground the shield at the power conditioner

Device that is acting as

LAS Scheduler was not

Ensure that all of the devices that are intended to be a Backup LAS are

a LAS does not send

downloaded to the Backup LAS

marked to receive the LAS schedule

out CD

device

 

All devices go off live

Live list must be reconstructed by

Current link setting and configured links settings are different. Set the current

list and then return

Backup LAS device

link setting equal to the configured settings.

Resource Block

 

 

Symptom

Possible Causes

Corrective Action

Mode will not leave

Target mode not set

Set target mode to something other than OOS.

OOS

 

 

 

Memory Failure

BLOCK_ERR will show the lost NV Data or Lost Static Data bit set. Restart the

 

 

device by setting RESTART to Processor. If the block error does not clear, call

 

 

the factory.

Block Alarms Will not

Features

FEATURES_SEL does not have Alerts enabled. Enable the report bit.

work

 

 

 

Notification

LIM_NOTIFY is not high enough. Set equal to MAX_NOTIFY.

Transducer Block Troubleshooting

 

Symptom

Possible Causes

Corrective Action

Mode will not leave

Target mode not set

Set target mode to something other than OOS.

OOS

A/D board check sum error

The A/D board has a checksum error.

 

Resource block

The actual mode of the Resource block is in OOS. See Resource Block

 

 

Diagnostics for corrective action.

 

Transducer Block

The actual mode of the Transducer Block is OOS.

The primary value is

Measurement

Look at the SENSOR_STATUS parameter (See Table 3-16 on page 3-21)

BAD

 

 

4-4

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Emerson 848T manual Transducer Block Troubleshooting, Foundation fieldbus, Symptom Possible Cause Corrective Action

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.