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Release Notes
Mimic v3.7.1 Release Notes
By Nobin William
Product: Mimic Simulation

The previous general released version is v3.7.0. This release, v3.7.1, comprises functionality enhancements and defect corrections discovered or reported in v3.7.0 or earlier.

Installation procedures are documented in the QuickStart Guide.

Release Components

Mimic v3.7.1
DeltaV Utility v4.1.53
TagBrowser v3.7.1
DeltaV VIM Firmware v2.3.18
DeltaV VIM2 Firmware v2.5.8

Who Should Upgrade?

Upgrade to this release is recommended for all Mimic users.

What's New in This Release?

Simulation Studio, the Mimic simulation configuration application, has been enhanced to include a Process Flow Diagram (PFD) style flowsheet to specify AMO based models. This functionality is a user selectable option. Users can continue to use the existing IEC1131 methodology, configure new models using the PFD style, and/or convert existing models from IEC1131 to PFD style. Conversion from IEC1131 to PFD style is done automatically by Simulation Studio; however, the resulting placement of stream connections and layout will require a cleanup effort. All underlying functionality remains the same when using IEC1131 or PFD styles. The benefits of the new PFD style are:

  • Space conservation so that a large process area can be condensed into a small flowsheet
  • Equipment and UnitOps are represented with easily recognizable graphic symbols
  • Reduction of clutter on the screen by allowing users to show only the values they want to see, e.g., stream flows
  • Easily see the process flow direction
  • Ability to select and position display of Equipment and UnitOp run-time values on the screen
  • Drag and drop objects from the pallet onto the flowsheet
  • Create stream connections between objects by clicking on a source point and drag the mouse pointer to a destination point

Model execution threads have been enhanced to include 10, 25, and 50 msec model execution. This fast model execution can be applied to Mimic base models as well as advanced models.

A pressure Regulator object has been added. It is designed to maintain a target pressure drop or pressure with VLE balance.

An Orifice Plate object has been added. It is designed to reduce the line pressure with VLE balance.

Future Value Function Block - This block computes the future value of a process variable and rate of change with a good signal to noise ratio. This block also computes the rate of change of the input and the value and time to peak rate of change.

PID Reset Functional Block - This block provides reset action that compensates for a variable measurement update time.

PID Performance Functional Block - This block can be used in conjunction with an ePID block to give the user information about their PID Performance. This block computes the integrated absolute error (IAE) and the peak error when LOAD_METRICS is enabled. If SETPT_METRICS are enabled, this block will compute the rise time, overshoot, undershoot, and settling time for a setpoint change. It will also compute the number of communications and test time to determine wireless battery life. Note that the times are in seconds but the IAE is in eu*minutes, and the peak error, overshoot, and undershoot are in engineering units (EU).

The Joule-Thomson (JT) effect calculation has been added to the outflow from Valves, Pressure Regulators and Orifice Plate objects.

When using component sets with Advanced Thermodynamics enabled, the Compressor object will now internally calculate the Heat Capacity Ratio for the outlet flow. The previous user defined heat capacity ratio functionality is maintained as an option.

New I/O bridge to support the Rockwell Logix Emulate interface API has been added.

Enhancements and Optimizations

Mimic Explorer

Added an easy way to add snapshot files into the Mimic database

Added progress indicator when performing large copy/paste operations

Backup log completion message is reported to the Mimic event log. Backup creation can fail if the disk is full or if the user does not have file permissions. The event message is a record of success or, in case of failure, reason for failure

Added MEMI2 Model Download and Stop menu for the External Model definitions so that all instances can be stopped and started independent of the node

Corrected Discrete Device Template editing. When editing a template from Mimic Explorer, if the number of DI or DO bits was changed quickly by clicking the arrows, the number of bits editable became different from the number specified in the Template definition

Tag Browser

Added new functionality to add/remove SIOTag and Initialization items from L5K files for Logix Emulate API interface

Logix Emulate

Added new bridge to perform I/O Access via DLL API

Bulk Generation Utility

The I/O Definition properties and SIO tag grid had a lot of read-only fields. Almost nothing in the IO definition properties could be modified, and SIO tags could not be added. Editing of these features has been implemented

Added capability to bulk generate and/or modify Unity OFS and Modbus I/O Definitions

Simulation Engine

Added Column/Stripper Tray level as browseable parameter. Tray level has been added to the run-time engine database. Previously, it was calculated and discarded. Now it is stored and exposed as a parameter value.

Added calculation of Heat Capacity Ratio when component set is configured for Advanced Thermodynamics and EOS. The ratio is then used to calculate outlet temperature, e.g., in a Compressor.

Added calculations for Cavett Liquid Enthalpy in NRTL based Thermodynamics with EOS component sets. The user can choose between Ideal + Excess Enthalpy or Cavett Correlation for computing the liquid enthalpy by manipulating the Liquid Enthalpy Model droplist. Ideal + Excess Enthalpy will compute the excess enthalpy based upon NRTL and add it into the ideal enthalpy computed from an Ideal Gas basis. Using Cavett Correlation will compute the Liquid Enthalpy based upon the Cavett liquid enthalpy model (which leverages component critical data). Cavett allows for estimation of enthalpy without relying on ideal gas as a basis.

Added simulation Speedup/Slowdown to the Logix Emulate bridge which uses the new Rockwell interface API. This functionality is now available in the release version of the Rockwell API.

Added functionality to calculate phase in Advanced Source object. The Advanced Source allows the user to put in any data, but this easily leads to specifying data that are not thermodynamically consistent. A new radio button has been added for the phase, i.e., to allow the user to define it or let the object calculate it internally. The default is User Defined. When User Defined is active, the Phase tag reference will be available, and Calculate will disable the tag reference. The configuration dialog also checks the component set to make sure it's not a pure component. If it's a single component, or if it's a pure component in a multi-component set, Calculate is grayed out and only User Defined is available.

Added functionality to externally calculate the phase in Vessel object (non VLE). An array reference in the vessel allows users to define the phase of each component for medium fidelity modeling of separations utilizing core modeling objects. To use this feature, a new mass integration type called "Custom Liquid/Vapor Separation" has been added. The User Interface rules are the same as for "Independent Liquid/Vapor Integration." When set to the new custom mode, the infinite source option is disabled. Two new array tags are enabled, "External Component Phase Array" and "Component Phase Enable Array." Not configuring "Enable Array" will result in all being enabled

Pump: Added a preconditioner to Pump polynomial inline solution. This change adds detection for cubic polynomials which cannot be analytically solved in double precision arithmetic. Consequently, the engine uses a fallback procedure to resolve the pump.

Execution suspended/slippage when running a multi-threaded simulation on a single core machine. If a Mimic database is multi-threaded, but placed on a single core, it does not execute all threads. While this is an expected issue with this setup, there is no indication that anything is wrong, since there is no slipping noted if there is no execution time. Consequently, the user is now notified on startup that the system is limited.

Added steam tables based on the 1997 standard. The previous libraries for the 1967 standard remain available for backward compatibility. Inclusion of the 1997 standard corrects inaccuracies in some functions using the 1967 standard due to interpolation, e.g., KFPT.

Modified so that streams have improved data consistency when using EOS component sets.

Modified how density is calculated in mixed flow streams. It is now implemented based on a global option, "Phase Density Mixing" vs. "Volume Density Mixing." Volume Density Mixing is the default for new databases, and Phase Density Mixing is the default for upgraded databases.

Modified the way the COND block evaluates comparison of double precision numbers. Instead of a straight equality, the comparison is now done with a precision of 1E-15.

Mimic Diagnostics

Moved thread information into its own branch. The addition of multiple user threads to Mimic has caused the number of threads per node to explode. This has led to thread information crowding out everything else in diagnostics. This thread information has been moved to its own branch under the node.

Simulation Studio

Added Power and Mass Flow Units to the Compressor object.

Modified configuration of the Air Cooled Hx to consolidate the way the configuration sheets are called.

Added default values to Advance Source object. The defaults are 20 DegC, 101.325 kPa and Phase of 1, i.e., Liquid water at standard state.

Corrected Valve K-Value editing - When a Valves K value is modified online and then the model goes offline, the user is prompted if changes should be saved. If you select no, everything seems fine, but when you go back online without a download, the Valve will be using the modified K value but the display will show the original K.

Mimic Help

Separator Help - The help files for the initial conditions of the Separator do not indicate that a stream with more than one component needs to be present to select options like Pressure-Level (calculate Temperature). When the stream contains only one component, the initial condition fields are greyed out and the default Temp-Level (calculate pressure) is selected. When a multi-component stream is selected, the options for Pressure-Temp (calc level) and Pressure-Level (calc Temp) become available.


Test Bench

Corrected Test Bench crash. This crash occurred when using arrow keys to navigate grid.

Mimic Explorer

Corrected model export defect. If a Calc block used defined global registers and/or constants, subsequent model export did not also export these global parameters. This resulted in Calc block errors. The referenced global registers and constants are now part of the model export.

Corrected XML export defect. If the user exported a graphic or snapshot, they did not get the required file that goes with the database entry. To receive these files required a separate, manual step. The external files have now been added to the XML export.

Mimic's documentation lists 32 VIMs as the running limit, but Explorer only allows 31 VIMs to be commissioned. This has been corrected and the Explorer now allows 32.

Corrected the download difference between Explorer and Simulation Studio which caused PVnRT function block error. The Gain parameter was not downloaded.

Mimic Modbus Bridge

Corrected Modbus Coil configuration. Modbus coils registers must be assigned to byte boundaries (both start and length be byte size) for proper updates to/from field devices. In the configuration dialog for these any register may be set for start (this should be limited to 1, 8, ...). The length may be set to any size, this is now limited to units of 8, 16, ...

Corrected Modbus bridge user interface for Slave mode while communicating with multiple field devices. Previously, it only communicated with a single device with ID=1. The bridge now has a mode which can be set to single device or gateway for multiple devices.

Added functionality to support Modbus Function Code 5. This function code allows users to force single coils on/off. Previous bridge version did not permit this.

Simulation Engine

Corrected error reporting for MEMI2 models. If a MEMI2 model overruns its update time, the engine sets all associated blocks in error. Subsequently, it did not clear this error if the MEMI2 model started to run in the allotted time.

Modified First Order Filter time constant – The filter time constant has been converted from integer to floating point to allow fractional time values. Mathematically, the filter time can be a non-integer positive number but was previously configured as an integer. Frequently, a 1 second filter is too large of a filter time because a 1 second filter takes 4 seconds to get to 90%. This modification also affects the AI, LTB, PID & SOF blocks.

Corrected the PRV function block to properly update the Cg parameter. If the PRV Cg is changed online (e.g., from 1 to 5), the flow and Cv will also change. If the model is taken to configuration mode and the 'Online Changes' window is cancelled, the original (1) value is shown in the configuration view of the PRV Cg. If the model is then taken back online with the play button (not downloaded), the PRV Cg shows the configuration value (1), but the Cv and Flow values are based on the engine Cg (5).

Corrected Compressor issue where high resistance on outlet stops compressor. Once the flow of the compressor stopped, such as by forcing the outlet K-factor to a high value to reach its minimum flow rate or maximum pressure ratio, the compressor never again tried to calculate flow; it stopped flow forever after this point.

Corrected Vessel so that the min/max pressure is maintained. In execution, for a given temperature, the Vessel will retain the correct amount of vapor holdup so that the pressure does not fall below the minimum.

Corrected Advanced Source and Vessel objects to propagate equilibrium values when using the Advanced Thermodynamics functionality. Currently the equilibrium values do not propagate which causes calculation consistency issues.

Corrected handling of 16-bit Signed Integer values coming from VIM Serial, Profibus and Devicenet signals. Mimic stores these 16-bit numbers as Unsigned before passing them to the AO blocks. This produced completely incorrect results for AO OUT or IParams in Mimic.

Corrected elevation handling related to Stream Output parameter. Incorrect handling impacted the PF Solver.

Corrected Heat Exchanger following snapshot restore. Restoring snapshot and downloading supporting standard model caused Heat Exchanger's Heat Transfer Coefficient to change from a referenced tag to a static value.

Corrected Dynamic Hx for proper usage of internally calculated phase. Phase is calculated in mass units, but is being used as moles in the dynamic heat exchanger, which will cause all phases to be slightly wrong if they're not pure vapor or liquid. Warning to existing users - if the DHX involves mixed phase outlet conditions, upgrading to v3.7.1 will not maintain previous results.

Corrected Separator defect - During mass integration the Separator does component by component integration. During this it is possible to end up with a negative amount of mass. Currently it will then create more mass to make a smooth approach to zero. This is nice in some cases as it gives a smooth response, but it is not physically accurate and can result in getting stuck in a feedback loop of mass creation. Instead of trying to be smooth, the functionality has been modified to be more correct (more since it's already in an invalid state by ever getting to a negative value, but no sense in compounding the issue) by just setting the component to 0.

Corrected executing of two vapor valves connected in series.

Corrected sight glass display names for Separator, Reactor, Surface Condenser, Jet Condenser and Vessel VLE objects.

Corrected Valve Hysteresis calculation for Discrete valves. Users could configure the parameters, but they had no impact on valve performance.

Corrected pumps where the downloaded curve has multiple solutions. The solution implemented is to keep the answer closest to the previous solution.

Corrected error message on Positive Displacement Pump. When a pump is configured with a centrifugal pump curve; but has positive displacement pump checked, it can activate false positive centrifugal pump errors such as "the max flow is greater than pump curve" error.

Corrected Vessel (VLE) Jacket energy creation issue. If a Vessel (VLE) is configured without both heat transfer coefficients for either the liquid or vapor phase, the outlet temperature of fluid going through the jacket will be the same as the temperature of the vessel. The jacket will show a Q_Jacket of 0 (as it should since there is no configured U) but the temperature of the fluid will change to whatever the vessel temperature is.

Corrected flow through StreamT where there is no flow when using the PF Solver and the flow is unstable when using the Node Solver.

Corrected Vessel so that it initializes to the correct phase when a component set with EOS is specified.

Corrected the state table logic for the MOV function block. Due to a discrepancy, the OPEN_LS_NO returned TRUE, and the OPEN_LS_NC returned FALSE, when the opposite was expected.

Corrected Valve leakage functionality. It was incorrect when the flow type is based on Velocity Head Loss Coefficients and the Valve is closed.

Corrected Streams so they now return the proper thermodynamically calculated Heat Capacity based on the temperature and composition.

Corrected liquid volume calculation in VH Flash when using Advanced Thermodynamics and EOS.

Corrected pressure drop calculations to eliminate unstable vapor flow through Valves for both Valve Cv and K-Factor resistance methods.

Simulation Studio

Corrected Multiple OParam writes error message - If multiple OParam blocks are writing to the same target, one of them will end up with "Block not present in run-time system or invalid path." which was not exactly helpful. The error message has been updated to reflect that another block is writing.

SPA S71 Communications

SPA SIMIT1 Snapshot

Corrected SPA bridge so that it does not crash when the API DLL is missing. If Siemens.SIMIT.CS.CSAPI.DLL is missing (or the wrong version), the SPA bridge crashed when the first API call was invoked. The bridge now reports that initialization has failed and shuts down.

1(SIEMENS, SIMATIC, STEP 7, S7-300, and S7-400 are trademarks of Siemens AG or its affiliates in the United State and in other countries)

Please contact us for any questions about these release notes.

Emerson Process Simulation
390 South Woods Mill Rd, Suite 100
Chesterfield, MO 63017 USA