Rosemount Manual: Rosemount 3051S Series of Instrumentation – Section 7: Advanced HART® Diagnostics Suite Manuals & Guides

Reference Manual
00809-0100-4801, Rev FA October 2010
Rosemount 3051S Series
Section 7 Advanced HART Diagnostic Suite
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7-1
User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7-3
Power Advisory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7-20
Diagnostic Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7-24
Variable Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7-26
Process Alerts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page 7-29
Service Alerts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7-31
Device Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7-32
Smart Wireless THUM Adapter Configuration . . . . . . . . . page 7-33
Rosemount 333 Hart Tri-Loop Configuration . . . . . . . . . .page 7-34
Safety Instrumented Systems (SIS) Certification . . . . . . page 7-36
Other Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 7-40
Field Communicator Menu Trees . . . . . . . . . . . . . . . . . . . page 7-41
OVERVIEW The Advanced HART Diagnostic Suite is an extension of the Rosemount 3051S
Series of Instrumentation and takes full advantage of the scalable architecture. The 3051S SuperModule™ Platform generates the pressure measurement while the diagnostic electronics board is mounted in the PlantWeb housing and plugs into the top of the SuperModule. The electronics board communicates with the SuperModule and produces standard 4 – 20 mA and HART outputs while adding advanced diagnostic capability.
NOTE
When a new SuperModule is connected to the diagnostic electronics board for the first time, the transmitter will be in alarm state until pressure range is specified.
The Advanced HART Diagnostics Suite is designated by the option code “DA2” in the model number. All options can be used with DA2 except the following:
Foundation Fieldbus protocol (Output code F)
Wireless (Output code X)
Quick Connect (Housing code 7J)
Junction box (Housing code 2A, 2B, 2C, 2J)
Remote display (Housing code 2E, 2F, 2G, 2M)
The HART Diagnostic transmitter has seven distinct diagnostic functions that can be used separately or in conjunction with each other to detect and alert users to conditions that were previously undetectable, or provide powerful troubleshooting tools.
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1. Statistical Process Monitoring (SPM) – SPM technology detects changes in the process, process equipment or installation conditions of the transmitter. This is done by modeling the process noise signature (using the statistical values of mean, standard deviation, and coefficient of variation) under normal conditions and then analyzing the recorded baseline values to current values over time. If a significant change in the current values is detected, the transmitter can generate HART alerts or analog alarms, depending on user configuration. The condition is time stamped and is also noted on the LCD.
The statistical values are also available as secondary variables from the transmitter via HART. Users can trend their process noise signature, perform their own analysis or generate their own alarms or alerts based on the secondary variables. Trending of statistical values in an analog system can be done with the Smart Wireless THUM Adapter or Rosemount 333 Tri-Loop. Refer to pages 7-33 and 7-34 for more details.
2. Power Advisory Diagnostic – This diagnostic functionality detects changes in the characteristics of the electrical loop that may jeopardize loop integrity. This is done by characterizing the electrical loop after the transmitter is installed and powered up in the field. If terminal voltage deviates outside of user configured limits, the transmitter can generate HART alerts or analog alarms.
3. Diagnostic Log – The transmitter logs up to ten device status events, each associated with the time stamp of when the event occurred. Referencing this log allows for better understanding of the device health and can be used in conjunction with device troubleshooting.
4. Variable Log – The transmitter logs the following values: Minimum and Maximum Pressure and Minimum and Maximum Temperature with independent time stamped values. The transmitter also logs total elapsed time in over-pressure or over-temperature conditions and number of pressure or temperature excursions outside of sensor limits.
5. Process Alerts – These are configurable alerts for both process pressure and sensor temperature. Users can receive a HART alert if pressure or temperature exceeds threshold limits. The time stamp of when the alert occurred and the number of alert events is also recorded in the transmitter. When alert is active, this notification is displayed on the LCD.
6. Service Alerts – This is a configurable service reminder that generates a HART alert after user-specified time has expired. When alert is active, this notification is displayed on the LCD.
7. Time Stamp – The diagnostic electronics board includes an embedded Operational Hours clock whose purpose is two-fold.
a. Provides the total number of operating hours of the transmitter.
b. Provides an elapsed “Time Since” event indication or time stamping
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for all diagnostics.
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All time values are non-volatile and displayed in the following format: YY:DDD:hh:mm:ss (years:days:hours:minutes:seconds). The time stamping capability significantly enhances the user’s ability to troubleshoot measurement issues, particularly transient events that may be too fast to capture with DCS or PLC trending or historian capabilities.
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Rosemount 3051S Series
USER INTERFACE The 3051S with Advanced HART Diagnostic Suite can be used with any asset
management software that supports Electronic Device Description Language (EDDL) or FDT/DTM.
Advanced HART Diagnostics is best viewed and configured using the latest Device Dashboard interface based on Human Centered Design concepts. The Device Dashboard can be obtained with DD revision 3051S HDT Dev. 3 Rev. 1.
The following screen shots are taken from Emerson Process Management’s AMS™ Device Manager, version 10.5. All screens shown are based on the Device Dashboard interface.
Figure 7-1. Device Dashboard
Diagnostic Action Settings
Figure 7-1 is the landing screen for the 3051S with Advanced HART Diagnostic Suite. The device status will change if any device alerts are active. Graphical gauges provide quick reading of the primary purpose variables. Shortcut buttons are available for the most common tasks.
Each diagnostic allows the user to select a type of action to take if the diagnostic is tripped.
None – Transmitter provides no indication that any trip values were exceeded
or the diagnostic is turned off.
Alert Unlatched – Transmitter generates digital HART alert and does not
affect the 4 – 20 mA signal. When conditions return to normal or within threshold levels, the alert is automatically cleared.
Alert Latched – Transmitter generates digital HART alert and does not affect
the 4 – 20 mA signal. When conditions return to normal, an alert reset is required to clear the status. This type of alert action is recommended if a 3rd party alert monitor software is likely to miss alerts due to slow polling of HART data.
Alarm – Transmitter drives mA output to the configured Failure Alarm level
(HIGH or LOW).
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Process Noise
Standard Deviation
Mean
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STATISTICAL PROCESS MONITORING
Introduction Statistical Process Monitoring (SPM) provides a means for early detection of
abnormal situations in a process environment. The technology is based on the premise that virtually all dynamic processes have a unique noise or variation signature when operating normally. Changes in these signatures may signal that a significant change will occur or has occurred in the process, process equipment, or transmitter installation. For example, the noise source may be equipment in the process such as a pump or agitator, the natural variation in the DP value caused by turbulent flow, or a combination of both.
The sensing of the unique signature begins with the combination of the Rosemount 3051S pressure transmitter and software resident in the diagnostic electronics to compute statistical parameters that characterize and quantify the noise or variation. These statistical parameters are the mean, standard deviation, and coefficient of variation of the input pressure. Filtering capability is provided to separate slow changes in the process due to setpoint changes from the process noise or variation of interest. Figure 7-2 shows an example of how the standard deviation value is affected by changes in noise level while the mean or average value remains constant. Figure 7-3 shows an example of how the coefficient of variation is affected by changes in the standard deviation and mean.
Figure 7-2. Changes in process noise or variability and affect on statistical parameters
The calculation of the statistical parameters within the device is accomplished on a parallel software path used to filter and compute the primary output signal (such as the 4 - 20 mA output). The primary output is not affected in any way by this additional capability.
Standard Deviation increases or decreases with changing noise level.
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Mean
Standard Deviation
Coefficient of Variation
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Rosemount 3051S Series
Figure 7-3. CV is the ratio of Standard Deviation to Mean
CV is stable if Mean is proportional to Standard Deviation.
SPM provides statistical information to the user in two ways. First, the statistical parameters can be made available to the host system directly via HART communication protocol or HART to other protocol converters. Once available, the system can make use of these statistical parameters to indicate or detect a change in process conditions. In the simplest example, the statistical values may be stored in a data historian. If a process upset or equipment problem occurs, these values can be examined to determine if changes in the values foreshadowed or indicated the process upset. The statistical values can then be made available to the operator directly, or made available to alarm or alert software.
The second way for SPM to provide statistical information is with software embedded in the 3051S. The 3051S uses SPM to baseline the process noise or signature via a learning process. Once the learning process is completed, the user can set thresholds for any of the statistical parameters. The device itself can then detect significant changes in the noise or variation, and communicate an alarm via the 4 – 20 mA output and/or alert via HART. Typical applications are detection of plugged impulse lines, change in fluid composition, or equipment related problems.
Overview A block diagram of the SPM diagnostic is shown in Figure 7-4. The pressure
process variable is input to a module where basic high pass filtering is performed on the pressure signal. The mean (or average) is calculated on the unfiltered pressure signal, the standard deviation calculated from the filtered pressure signal. These statistical values are available via HART and handheld communication devices like the 375 Field Communicator or asset management software like Emerson Process Management’s AMS™ Device Manager. The values can also be assigned as secondary variables from the device for 4-20 mA communication to the user through other devices like the Smart Wireless THUM or Rosemount 333 HART Tri-loop.
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Process Variable
Statistical
Calculations
Module
Learning
Module
Decision
Module
Standard Outputs (4-20 mA / HART)
Control Inputs
Outputs
HART alert / 4-20 mA alarm
Resident in Transmitter
Statistical Parameters
Baseline Values
Figure 7-4. Statistical Process Monitoring diagnostic resident in transmitter
SPM also contains a learning module that establishes the baseline values for the process. Baseline values are established under user control at conditions considered normal for the process and installation. These baseline values are made available to a decision module that compares the baseline values to the most current statistical values. Based on sensitivity settings and actions selected by the user via the control input, the diagnostic generates alarms, alerts, or takes other actions when a significant change is detected in either value.
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Learning/Verifying
Monitoring
User Initiatives
Compute mean,
std. dev. for
3 min.
Sufficient
Noise?
Compute 2nd
mean, std. dev.
for 3 min.
System Stable?
System Stable?
“Insufficient
Dynamics”
Change Status
Compute mean (X)
and std. dev. ( )
Decrease in
> 60%?
“Low Variation
Detected”
“High Variation
Detected”
Increase in
> 60%?
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
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Figure 7-5. Simplified SPM flowchart
Rosemount 3051S Series
Further detail of the operation of the SPM diagnostic is shown in the Figure 7-5 flowchart. This is a simplified version showing operation using the default values. While SPM continuously calculates the mean, standard deviation, and coefficient of variation values, the learning and decision modules must be turned on to operate. Once enabled, SPM enters the learning/verification mode and the status will be “Learning”. The baseline statistical values are calculated over a period of time controlled by the user (Learning/Monitoring Period; default is 3 minutes). A check is performed to make sure that the process has a sufficiently high noise or variability level (above the low level of internal noise inherent in the transmitter itself). If the level is too low, the diagnostic will continue to calculate baseline values until the criteria is satisfied (or turned off). A second set of values is calculated and compared to the original set to verify that the measured process is stable and repeatable. During this period, the status will change to “Verifying”. If the process is stable, the diagnostic will use the last set of values as baseline values and change to “Monitoring” status. If the process is unstable, the diagnostic will continue to verify until stability is achieved. The stability criteria are also user defined.
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In the “Monitoring” mode, statistical values of mean, standard deviation, and coefficient of variation are continuously calculated, with new values available every second. When using mean and standard deviation as the SPM variables, the mean value is compared to the baseline mean value. If the mean has changed by a significant amount, the diagnostic can automatically return to the “Learning” mode. The diagnostic does this because a significant change in mean is likely due to a change in process operation and can result in a significant change in noise level (i.e. standard deviation) as well. If the mean has not changed, the standard deviation value is compared to the baseline value. If the standard deviation has changed significantly and exceeds configured sensitivity thresholds, this may indicate a change has occurred in the process, equipment, or transmitter installation and a HART alert or analog alarm is generated.
For DP flow applications where the mean pressure is likely to change due to changing process operation, the recommended SPM variable for process diagnostics is the coefficient of variation. Since the coefficient of variation is the ratio of standard deviation to mean, it represents normalized process noise values even when the mean is changing. If the coefficient of variation changes significantly relative to the baseline and exceeds sensitivity thresholds, the transmitter can generate a HART alert or analog alarm.
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Assigning Statistical Values to Outputs
Device Dashboard
Fast Keys
2, 2, 5, 1
NOTE
SPM diagnostic capability in the Rosemount 3051S HART pressure transmitter calculates and detects significant changes in statistical parameters derived from the input pressure signal. These statistical parameters relate to the variability of and the noise signals present in the pressure signal. It is difficult to predict specifically which noise sources may be present in a given pressure measurement application, the specific influence of those noise sources on the statistical parameters, and the expected changes in the noise sources at any time. Therefore, Rosemount cannot absolutely warrant or guarantee that SPM will accurately detect each specific condition under all circumstances.
The statistical values of mean, standard deviation, and coefficient of variation can be made available to other systems or data historians via HART communication. WirelessHART adaptor, such as the Smart Wireless THUM can also be used to obtain additional variables. Devices that convert HART variables to analog 4-20 mA outputs, such as the Rosemount 333 Tri-Loop can also be used.
Statistical values can be assigned to be 2nd variable, 3rd variable, or 4th variable. This is accomplished through Variable Mapping. See Figure 7-6.
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Figure 7-6. Selection of statistical values as secondary variables
Rosemount 3051S Series
SPM Configuration For inexperienced users, guided setup is recommended. Guided setup walks
Device Dashboard
Fast Keys
Figure 7-7. Guided Setup Menu
2, 1, 2, 1
the user through settings that configure the SPM diagnostic for most common usage and applications.
The rest of the configuration section explains the parameters for manual configuration of SPM diagnostic.
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Figure 7-8. Statistical Process Monitoring main screen
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The SPM Status screen shows overview information for the diagnostic.
The process for operation of the SPM diagnostic is:
Configure the diagnostic using Baseline Configuration and Detection Configuration screens.
Turn on the diagnostic from the SPM Status screen.
The configuration process starts with Baseline Configuration, Figure 7-9 on page 7-11. The configurable fields are:
SPM Variable:
This is the statistical variable to be used for SPM diagnostic detection.
Stdev & Mean (default)
Standard deviation and mean of the process are calculated. Users can set independent sensitivity thresholds for both statistical variables.
Coefficient of Variation (CV)
CV is calculated from the ratio of standard deviation to mean and is better suited for DP flow applications where the mean pressure is likely to change due to changing process operation. CV puts standard deviation in context of the mean and is represented as a % value.
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3 min.
5 min.
10 min.
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Figure 7-9. Baseline Configuration screen
Rosemount 3051S Series
Figure 7-10. Effect of Learn/Monitor Period on Statistical Values
Learn/Monitor Period:
This is the learning and monitoring time period that SPM diagnostic uses to sample the pressure signal. The mean and standard deviation or coefficient of variation values determined during the learning period will become the Baseline values. Decreasing this period can speed up the set up time and is recommended for stable process operations. Increasing this value will give a better baseline value for noisier processes. If false trips for “High Variation Detected” are occurring due to rapid changes in the process and statistical value, increasing the learning period is recommended. The Learning/Monitoring Period is always set in minutes. The default value is 3 minutes and the valid range is 1 to 60 minutes.
Figure 7-10 illustrates the effect of Learn/Monitor Period on the statistical calculations. Notice how a shorter sampling window of 3 minutes captures more variation (e.g. plot looks noisier) in the trend. With the longer sampling window of 10 minutes, the trend looks smoother because SPM uses process data sampled over a longer period of time.
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Rosemount 3051S Series
Power Interruption Action
This is used to direct what the diagnostic should do in the case of a power interruption or if the diagnostic is manually disabled and then enabled. The options are:
Monitor (default)
When SPM restarts, the diagnostic returns to the Monitoring mode immediately and uses the baseline values computed before the interruption.
Relearn
When SPM restarts, the diagnostic enters the Learning mode and will recalculate new baseline values.
Low Pressure Cut-off
This is the minimum pressure required to operate the diagnostic with Coefficient of Variation selected as the statistical variable. The coefficient of variation is a ratio of standard deviation to mean and is defined for non-zero mean values. When the mean value is near zero, the coefficient of variation is sensitive to small changes in the mean, limiting its usefulness. Default value is 1% of upper sensor limit.
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Insufficient Variability
The SPM diagnostic uses process noise to baseline the process and detect abnormal situations. Typically the Insufficient Variability check is on to ensure there is sufficient noise for proper operation. In a quiet application with very minimal process noise, this setting can be turned off. The default setting is ON.
Parameter Definition
On (default) Perform insufficient variation check Off Do not perform insufficient variation check
Standard Deviation Difference, Mean Difference
If these difference values are exceeded during the Verification mode, SPM diagnostic will not start Monitoring mode and will continue verifying the baseline. If SPM diagnostic will not leave the Verification mode, these values should be increased. If the diagnostic still remains in the Verification mode with the highest level, the Learning/Monitoring period should be increased.
Table 7-1. Standard Deviation Verification Criteria
Parameter Definition
None Do not perform any verification checks for standard deviation. 10% If the difference between baseline standard deviation value and the
verification value exceeds 10%, diagnostic will stay in Verification mode.
20% (default) If the difference between baseline standard deviation value and the
verification value exceeds 20%, diagnostic will stay in Verification mode.
30% If the difference between baseline standard deviation value and the
verification value exceeds 30%, diagnostic will stay in Verification mode.
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Figure 7-11. Detection Configuration screen for Standard Deviation & Mean
Rosemount 3051S Series
Table 7-2. Mean Verification Criteria
Parameter Definition
None Do not perform any verification checks for mean. 3 Stdev (default) If the difference between baseline mean value and the verification
value exceeds 3 standard deviations, diagnostic will stay in Verification mode.
6 Stdev If the difference between baseline mean value and the verification
value exceeds 6 standard deviations, diagnostic will stay in Verification mode.
2% If the difference between baseline mean value and the verification
value exceeds 2%, diagnostic will stay in Verification mode.
The Detection Configuration screen (Figure 7-11 and Figure 7-12) allows for
configuration of sensitivity threshold values for tripping the diagnostic and how to receive the HART alert or analog alarm.
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Figure 7-12. Detection Configuration screen for Coefficient of Variation
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Figure 7-13. Preset sensitivity levels
Standard Deviation Sensitivity, Mean Sensitivity
Shows the current sensitivity level for detecting changes in standard deviation or mean. Users can choose from preset values of High, Medium, and Low. Custom sensitivity levels can also be configured.
Coefficient of Variation Sensitivity
Shows the current sensitivity level for detecting changes in the coefficient of variation. Users can choose from preset values of High, Medium, and Low. Custom sensitivity levels can also be configured.
Figure 7-13 illustrates the differences in preset sensitivity limits of High, Medium, and Low. The preset High sensitivity setting (e.g. 20%) will cause the SPM diagnostic to be more sensitive to changes in the process profile. The preset Low sensitivity setting (e.g. 80%) will cause the SPM diagnostic to be less sensitive as a much greater change in the process profile is needed to trip the alert.
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