The Fieldbus Diagnostics Difference

©2013 Fieldbus Foundation

FOUNDATION Fieldbus: the Diagnostics Difference


• There’s Diagnostics and There’s Diagnostics.

• The Value of Fieldbus Diagnostics

• Physical Layer Diagnostics

• Managing the Diagnostics Storm

• PAM and IDM Software, Work Processes and Training



Why do we Use Diagnostics?

• Diagnostics can be a valuable tool that can help save you time and money and avoid unplanned shutdowns.

• Diagnostic data can be vague and require a lot of digging to get to the root cause.

• Diagnostic data can also provide you with avalanche of useless information that can grind your process to a halt.

• Not all technologies handle diagnostic information the same way.

• Trick is to get only the right information, at the right time, to the right people.


The Current State of Non Digital Diagnostics: Or the Idiot Light

• Doesn’t tell you what’s wrong

• No predictive guidance

• Is it a process problem or device problem?

• Sensor problem? Electronics problem? Who knows.

• Doesn’t tell you what’s wrong

• No predictive guidance

• Is it a process problem or device problem?

• Sensor problem? Electronics problem? Who knows.


The FOUNDATION Fieldbus Diagnostics Difference

• FOUNDATION fieldbus has a unique approach to management of device diagnostics.

• The publish/subscribe structure of FOUNDATION fieldbus means that diagnostic information is available immediately to a wide range of workers in the plant.

• Data is available at all times and is constantly being updated.

• Allows you to organize and prioritize data in a way that turns it into useful information for the right people at the right time.

• FOUNDATION fieldbus has a unique approach to management of device diagnostics.

• The publish/subscribe structure of FOUNDATION fieldbus means that diagnostic information is available immediately to a wide range of workers in the plant.

• Data is available at all times and is constantly being updated.

• Allows you to organize and prioritize data in a way that turns it into useful information for the right people at the right time.


Fieldbus Device Alerts Bring the Data to the Front

Early warning systemGives operators more time to take

action before device problem affects the process

Time-stampedSequence of event recordingRelate problem time to true

causative factors


Actionable Information

In the past, device alarms were not displayed with actionable information Just error messages or cryptic codes – “Error 13” The technician didn’t know what to do

Device alarms must be displayed with advice that maintenance technicians can act upon

Use devices which provide guidance for the device diagnostic alarms...

Understandable Provide a clear message that is easily understood, not a cryptic code

Diagnostic Helps with the identification of the problemAdvisory Provides guidance towards the correct actionFocusing Directs attention to the important aspects


Distinctions should be made between Instrument and Process Diagnostics

Sensorincluding process connection and sensor

electronic

Instrument Electronic

Configuratione.g. Linearization

ProcessProcess/

Environment

Information

Root GroupInformationInformation

RootRoot GroupGroup

InstrumentInstrument

Process/Environment

Process/Environment

SensorSensor

ElectronicsElectronics

ConfigurationConfiguration

ProcessProcess


Data Quality Indication in Action


Device Problem or Process Problem – Do you have sufficient data to guide you?

Hardwired

Device drives current <4 mA or >20 mA on device failure

Masquerades as a process problem

PID counteracts thus tripping the loop

Operator cannot tell the difference between a process alarm and a device alarm

Fieldbus

Device health indicated by associated status

Clear distinction between device problem and process problem

Controller holds last position and alarms on device failure

Shutdown is optional

Operator can easily distinguish process problem from a device problem


After the Fix – Embedded Causes?

When was device configuration changed?

Who did it?

What was changed?


Fieldbus Pressure Transmitter Data Provides:

More versatile statistical process monitoring

Uses process “noise” to detect process problems:

Pulsation indicative of pump or compressor damage

Entrained air = flow measurement errors

Leaks in impulse lines and manifolds

Plugged impulse line


Fieldbus Temperature Transmitter Data Provides:

Statistical process monitoring:Hydrate formation, scaling formation,thermowell coating, etc.

Predictive thermocouple degradation diagnostics - before a T/C or RTD fails,

Extreme Temperature Tracking

Heat conducted from integral sensor to transmitter housing


Fieldbus Control Valve Positioner Data Provides:

Continuous (not on-demand) Performance Diagnostics:Actuator/tubing leakage, air supply

availability, calibration shift, etc.

Common DiagnosticsPartial Stroke Testing (PST), travel

histogram, step-response, valve signature, pressure sensor failure, travel deviation, reversal count alert, accumulated travel alert, supply pressure, position feedback…


Fieldbus On/Off Valve Data Provides:

Open/close travel time On/Off Valve

Cycle counts

Stuck valve


Fieldbus Data Goes Beyond “Common” Transmitters and Valves

Gas Chromatographs

Tank Gauging Systems


Segment data can provide a good analysis of the system’s health and may include:

Communications Data - Testers/Communicators

Monitoring and diagnostics Online and in real-time

with remote access Simple-to-interpret data reports Built-in oscilloscope for visual detail


Data can Appear in a Variety of Forms

Diagnostic WindowsDiagnostic

Lamps


OK, so FOUNDATION Fieldbus clearly can provide the data I have always wanted…

So what can possibly stop me from getting the most value from the data?...


The Power is in the Data, and there can be a lot of data!

Manufacturer (Coded)

A B C D E F G H I J K L

Block Type Number of Parameters in each block

XD 1 (generally the measurement transducer) 44 106 85 34 37 91 45 29 45 61 45 42

XD 2 38 42 36 50 34 27

XD 3 93 20

XD 4 55 17

XD 5 33

# of parameters 230 148 121 34 37 211 45 29 79 88 45 42

# of Transducer Block Parameters in d/p transmitters.

Extracted from Differential Pressure Transmitters with similar capsule ranges

At least one device contained~75 parameters specifically for specialized diagnostics

Different Manufactures = different levels of granularity (data)


The Diagnostics Storm

Sample Diagnostic Parameters of a

FOUNDATION Fieldbus Flowmeter


NAMUR NE 107

Definition of NE 107 Status Signals


Definition of NE 107 Status Signals


32 Bit Bitstring for Prioritizing Diagnostic Data


Grouping Diagnostic Conditions


Diagnostic Mapping Workflow


Embedded in Supplier Solution


Utilizing Diagnostic Data from Multiple Devices Together

Utilizing Diagnostic Data from Multiple Devices

• Certain diagnostic anomalies expressed in multiple field devices can indicate an anomaly or impending abnormal situation in the process.

• Placing a structure around which these diagnostics can be consistently managed makes these more advanced diagnostics possible.

• Being able to diagnose the overall health of a unit, area, or even the entire plant is predicated on this good diagnostic data at the most basic level of the measurement devices and actuators.

• Certain diagnostic anomalies expressed in multiple field devices can indicate an anomaly or impending abnormal situation in the process.

• Placing a structure around which these diagnostics can be consistently managed makes these more advanced diagnostics possible.

• Being able to diagnose the overall health of a unit, area, or even the entire plant is predicated on this good diagnostic data at the most basic level of the measurement devices and actuators.


Plans for Using a Plant Asset Management System


Location of Intelligent Device Management Software

In the past, intelligent device management software fell into disuse because it was not easily accessible Hidden away in the workshop Local equipment room (LER) / field auxiliary room (FAR) Stand-alone workstation in the corner of the control room

• Separate login

• Must type the tag to search

Must be accessible to become a natural part of the daily work process Client integrated on the operator console

• A mindset change

• The idea is not for operators to take over maintenance Dedicated maintenance workstation for instrument technicians


Engineering Operator Operator Operator Maintenance

Traditional Architecture

Operators Using Device Diagnostics as Early Warning for Process

• Intelligent device management client integrated in DCS operator console

• Device diagnostics becomes a natural part of daily operations

• Operators tend to the process, not the devices

Plus:Process visibility

Plus:Device Diagnostics

Plus:Device Configuration


Training for New Competency

In the past the operators got training on the operator station software But not the device management software

The technicians got training on the handheld field communicator But not the device management software

Make sure operators and technicians are trained on the device management software Understand the NE107 status signals Navigate the device menu How to search for tags, plant unit, device

classes How to search for specific device types


Work Processes Have to Be Rewritten Around Device Management Software

Standard company work processes for 4-20 mA and on/off signals are not optimized for intelligent devices Technicians start by going to the field to inspect

Rewrite work processes around the device management software Urgent maintenance:

• Troubleshoot and verify from the device management software first, before going to the field, to determine if there is a problem

Daily maintenance:

• Extract device diagnostic alarm report from intelligent device management software, and prioritize before morning meeting

Turnaround maintenance:

• Screen which devices need calibration and adjustment to better plan the turnaround activities


Let’s Now See Device Diagnostics in Action!


Date post:	28-Jan-2015
Category:	Technology
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The Fieldbus Diagnostics Difference

Technology