Method for testing a firmware intended to be installed in a programmable control unit and automatically generate a report on the operation of a plant and related program

Abstract

This disclosure provides a computer-implemented method for testing firmware intended to be installed in a programmable control unit and automatically generating an operation report for a plant comprising an HVAC / R unit and related mechanical components when said firmware is executed, wherein the plant is controlled by at least one programmable control unit running the firmware that implements control logic of the plant. The program, when executed by the computer, generates a graphical user interface on a computer screen that allows the user to select at least one HVAC / R unit and its mechanical components, as well as select the size and operating parameters of the mechanical components, and then generate a graphical image representing the plant. The plant's operation is then simulated using a computer and an operation report of the plant is automatically generated. This report includes a graphical representation of the plant, generated using a graphical user interface, as well as values of the system's physical state parameters superimposed on the graphical image corresponding to the areas where these physical parameters would be measured in the real plant. This generates an intuitive performance report that allows the effects of the selected control logic to be verified and, therefore, real-time adjustments to the program to be implemented by the programmable control unit of the plant. The method described is implemented using a related computer program.

Description

[0001] METHOD FOR TESTING A FIRMWARE INTENDED TO BE INSTALLED IN A PROGRAMMABLE CONTROL UNIT AND AUTOMATICALLY GENERATE A REPORT ON THE OPERATION OF A PLANT AND RELATED PROGRAM

[0002] TECHNICAL FIELD

[0003] The present invention relates to heating, ventilation, and air conditioning plants, and more specifically to a method for testing firmware intended for installation in a programmable control unit and automatically generating a performance report of a plant and related program executed by a computer.

[0004] BACKGROUND

[0005] Heating, ventilation, and air conditioning (HVAC) plants are widespread. These systems often consist of numerous types of appliances, each type of appliance having different possible configurations. When interconnected, the appliances offer a large number of functionalities. The operational controls and management of these systems can become sophisticated and require knowledge and expertise to configure each piece of appliance in the plant and use it correctly so that, the plant performs the desired task. There is a need for a simulator that allows users to easily understand how each appliance operates, how the entire plant would respond under certain environmental conditions, and how the plant's functioning would be affected by changes to the control logic implemented by a programmable control unit.

[0006] SUMMARY

[0007] To at least partially address the above-mentioned need, this disclosure provides a computer-implemented method for testing firmware intended to be installed in a programmable control unit and for automatically generating an operation report for a simulated plant comprising an HVAC / R unit and related mechanical components when the firmware is executed, wherein the plant, is controlled by at least one programmable control unit running the firmware that implements control logic of the plant.

[0008] The method is implemented by a computer running a program comprising software code that, when executed by the computer, generates a graphical user interface on a computer screen that allows the user to select at least one HVAC / R unit and its mechanical components, as well as select the size and operating parameters of the mechanical components, and then generates a graphical image representing the plant. The operation of the plant is then computer-simulated and an operation report of the simulated plant is automatically generated that includes a representative graphical image of the plant, generated using a graphical user interface, as well as values of the plant’s physical status quantities superimposed on the graphical image at the locations where these physical quantities would be measured in the actual plant when controlled by the programmable control unit running the firmware.

[0009] The method as defined in the enclosed claim 1 contemplates the step of loading a firmware to be tested in a memory of the computer and the step of running the firmware in the computer to generate, with the first software module (Simulator), simulated commands that are provided to the second software module (Virtual Loop) that simulates the functioning of the HVAC and of the mechanical components of the plant. In practice, the first software module (Simulator) simulates the operation of the programmable control unit of the plant when executing the firmware, whilst the second software module (Virtual Loop) simulates the operation of the HVAC unit and of the mechanical components of the plant. Therefore, the first software module (Simulator) generates simulated commands that correspond to the commands that would be generated in the real world by the programmable control logic of the plant when running the firmware on the basis of values of physical state quantities in zones of the plant, the second software module (Virtual Loop) simulates the operation of the HVAC unit and of the mechanical components of the plant according to these commands and calculates values of the physical state quantities. The computer program that simulates the operation of a plant is thus split into two software modules that interact with each other: the first software module (Simulator) needs the firmware (intended to be installed in the real-world programmable control unit of the plant) in order to simulate the commands that would be generated by the real-world programmable control unit of the plant when running the firmware; the second software module (Virtual Loop) receives the commands generated by the first software module (Simulator) and simulates the operation of the real-world HVAC unit and mechanical components of the plant.

[0010] This generates an intuitive operating report that allows verification of the effects of the selected control logic and, therefore, real-time adjustment of the firmware code to be executed by the plant's programmable control unit. This allows a programmable control unit programmer to verify whether the plant is responding as desired, even under extreme conditions, without requiring detailed knowledge of the operation of the HVAC / R unit and of its mechanical components.

[0011] The described method is implemented through a related computer program executed by a computer.

[0012] Further embodiments are defined in the appended claims.

[0013] BRIEF Di ASCRIPTION OF THE DRAWINGS

[0014] Figure 1 shows an example of the graphical user interface of the program according to this disclosure, in an initial phase in which the user may configure the plant to be simulated.

[0015] Figure 2 shows how users may configure the plant to be simulated by modifying what the graphical user interface (GUI) show's in Figure 1.

[0016] Figure 3 illustrates the various sections of the GUI that allow users to describe the plant to be simulated.

[0017] Figure 4 shows how to select certain characteristics, such as the refrigerant type, of the plant to be simulated in Figure 3.

[0018] Figure 5 shows how the graphical user interface may be used to define the mechanical components of the plant to be simulated.

[0019] Figure 6 is a schematic diagram illustrating an embodiment of the computer program according to this disclosure, consisting of a first software module Simulator for executing a firmware to be tested to simulate the operation of the programmable control unit that implements the control logic of the plant, by executing the firmware, interfaced with a second software module Virtual Loop that simulates the operation of the plant as represented by the graphical user interface.

[0020] Figure 7 illustrates the section of the computer program shown in Figure 6 so that the second software module Virtual Loop may interact with the first software module Simulator, which runs the firmware to be tested.

[0021] Figure 8 shows a page of the graphical user interface that allows to define initial values and boundary conditions of the plant to be simulated.

[0022] Figure 9 illustrates various parts of the graphical user interface shown in Figure 8 for setting the temperature trend over the course of a day in a room where the plant is installed.

[0023] Figure 10 is a sample screenshot showing the humidity trend over the course of a day in a room where the plant is installed.

[0024] Figure 11 shows a sample screenshot showing how to generate predefined time graphs of the state variables of the mechanical components of the plant to be simulated.

[0025] Figure 12 is a sample screenshot of an operating report in which the graphical image of the plant is superimposed with the values of the physical state variables of the plant corresponding to the respective zones of the plant.

[0026] Figure 13 is another sample screenshot of an operating report, wherein, besides the values of the physical status variables of the plant as shown in figure 12, it also shows time graphs, set as shown in figure 11, of the status variable trends.

[0027] Figure 14 is a detailed view7of the time graphs of the automatically generated operating report shown in figure 13.

[0028] Figure 15 is a sample screen where the left portion corresponding to figure 11 is generated by the second software module Virtual Loop and the right portion displaying the firmware code to be tested is generated by the first software module Simulator.

[0029] Figure 16 is a detailed view of the portion of the screen in Figure 15 generated by the first software module Simulator.

[0030] Figure 17 is a sample screen where the left portion corresponding to figure 13 is generated by the second software module Virtual Loop and the right portion displaying the firmware code is generated by the first software module Simulator.

[0031] Figure 18 is a detailed view of the portion of the screen in figure 17 generated by the first software module Simulator.

[0032] Figure 19 is another sample screenshot wherein the left portion is generated by the second software module Virtual Loop and the right portion displaying the firmware code is generated by the first software module Simulator.

[0033] Figure 20 is a detailed view of the screen portion of figure 19 generated by the first software module Simulator, showing the debug interface WATCH.

[0034] DESCRIPTION OF ILLUSTRATIVE EMBODI MENTS

[0035] The method according to this disclosure will be illustrated with reference to the accompanying figures 1 to 20, which refer to an embodiment. In general, the method for testing firmware intended to be installed in a programmable control unit and automatically generating an operation report for a plant comprising an HVAC / R unit and related mechanical components - wherein the plant is controlled by at least one programmable control unit implementing a control logic - is implemented through a computer running a program to generate a graphical user interface that has: a first section (A), configured to allow a user to select identifying information for an HVAC / R unit and its mechanical components from a menu; a second section (C, D), configured to allow the user to select the size and operating parameters of the mechanical components; a third section (B), configured to show the user a graphic image representing the plant; a setup section configured to allow the user to set initial values of the plant and boundary values for physical environmental parameters of the environment in which the plant is located.

[0036] Once the plant diagram to be simulated has been set up, as described in figures 1 to 5, the operation of the plant is simulated by calculating values of physical state quantities in zones of the plant that evolve over time, when the plant is in operation, based on mathematical models of the HVAC / R unit's operation and the operation of the mechanical components based on how the graphic symbols are connected to each other in the graphic image.

[0037] As shown in figures 8 to 10, the graphical user interface can also be used to set initial values of the plant and boundary values of physical environmental parameters in which the plant is located, based on a control logic of the plant implemented by the programmable control unit of the plant. Therefore, according to the method of this disclosure, the operation of the plant is simulated as represented in the graphical user interface and an operation report of the plant is automatically generated, such as that in figure 12. This report can be simply displayed on the screen or printed on paper, and includes at least the graphic image representing the plant and the values of the physical system status quantities superimposed on the graphic image corresponding to the relevant zones of the plant to which such physical quantities refer. According to one aspect, it is also possible to supplement the operation report of the plant with graphs illustrating the time graph of the values of physical state quantities in a zone of the plant, as illustrated for example in the screenshot in figure 13 and the detailed view7in figure 14. Conveniently, to generate these time graphs, the graphical user interface will be configured, for example, as illustrated in figure 11, so as to allow7a user to set the characteristics of standard graphs to be produced in the operation report of the plant.

[0038] As illustrated schematically in figure 6, a computer program for implementing the method according to the present disclosure comprises: a first software module (Simulator) for simulating the implemented control logic of the plant, by executing the firmware code to be tested, from the programmable control unit of the plant, to receive the values of physical status variables in zones of the plant and to generate, by executing the firmware code in the first software module (Simulator), control commands for the operation of the HVAC / R unit and mechanical components based on the control logic of the plant; a second software module (Virtual Loop) for simulating the operation of the HVAC / R unit and mechanical components. The second software module is configured to generate the graphical user interface and communicate with the first software module (Simulator) to receive control commands for the operation of the HVAC / R unit and mechanical components of the plant and to calculate the values of the physical status variables.

[0039] Figures 15 through 18 show7that the firmware to be tested, loaded into the computer running the Virtual Loop and Simulator software modules, is distinct and separate from both the second software module (Virtual Loop) and the first software module (Simulator). According to one aspect that can be seen more clearly in the detailed figures 16 and 18, a programming interface can be opened in the first software module (Simulator), allowing a programmer to modify the firmware code and save a modified version of the firmware before simulating the plant's operation again.

[0040] A programmer is therefore presented (figures 15 and 17) with a screen on the left showing the operation report of the plant, and a screen on the right with the programming interface showing the firmware code lines. The programmer may then correct the firmware code as soon as he or she notices, from the generated operation report, that the firmware code — readable in the central pane of the detailed views in figures 16 and 18 — does not allow to control the plant as desired.

[0041] Figures 19 and 20 are similar to figures 17 and 18 and refer to another plant simulation. According to one aspect, the first software module (Simulator) has a debug interface WATCH, better readable in the detailed view of Figure 20, configured to display operating parameter values defined in the firmware, but which do not necessarily appear in the plant diagram displayed by the second software module (Virtual Loop). In the shown example, the firmware contains, on line 268, the definition of the regulation routine of a PID controller, which acts on the simulated plant, and on lines 269 and 270 respectively, the value of the flow water temperature Ain Data. Fct.WaterOut and the set temperature value LWT_MainSetP used to calculate this regulation. These values are used by the firmware code block that defines the routine to update the classic parameters Kp (proportional coefficient), Ti (integration time constant), and Td (derivative time constant) of the PID controller. Thanks to the debug interface WATCH, the programmer may conveniently view the flow water temperature value Ain Data. Fct.WaterOut (24.8°C, also reported in the report of the second software module Virtual Loop on the left in figure 19) and the set temperature value LWT_MainSetP (29.0°C) and a PID control value (57%) calculated by the firmware, which are not shown in the report of the second software module Virtual Loop.

[0042] Thanks to this organization of the computer program into two interacting software modules, it is possible to obtain a performance report for the same plant by simply modifying the control logic to be implemented, determined by the firmware code being tested, or to automatically generate a performance report for different plants subject to the same control logic. Once it has been verified that the firmware implements a control logic suitable for controlling the plant, the programmer may save the firmware code which remains distinct and separate from the software modules Simulator and Virtual Loop -----and may load it into a programmable control unit intended to actually control the HVAC plant whose operation has been computer-simulated.

[0043] Software modules that simulate the operation of PCUs that implement control logic of the plant are currently commercially available and are considered a very useful tool for programming a programmable control unit of a plant and verifying that the software loaded into them performs the desired operations.

[0044] The first software module (Simulator) includes a programming interface for writing a program defining the control logic of the plant. This way, programmers may generate an operation report of the plant as soon as they have finished writing their control logic program. This allows them to understand whether the set control logic is effective or not, even if they are not familiar with the operation of the HVAC / R unit and how its mechanical components affect the plant itself. This will reduce errors in programming the programmable control unit of the plant, even in extreme operating conditions of the plant.

[0045] To this end, the graphical user interface will contain a section, shown for example in Figure 7, where the user can map the information exchange between the first software module Simulator and the second software module Virtual Loop. In this way, the same second software module Virtual Loop can be adapted to interface with different first software module Simulators, which may require and provide different information to simulate the operation of the programmable system control unit.

[0046] Hereinafter, this disclosure wall describe in detail an embodiment in which the program implementing the method according to this disclosure is organized as shown in Figure 6, with a first software module Simulator and a second software module Virtual Loop interfaced to exchange data.

[0047] The second software module Virtual Loop simulates the physical behavior of HVAC / R units based on predefined and configurable mathematical models. It receives the state of the actuators in the HVAC / R unit as input data and recreates, based on boundary conditions, the physical variables present in the unit in response to the system.

[0048] The actuators, for example, include: compressor, expansion valve, circulation pumps, source fan, cycle reversal valves, etc.

[0049] The recreated variables, for example, are: suction and discharge pressures, suction and discharge temperatures, delivery and return water temperatures, etc.

[0050] The main behaviors of the unit’s safety and monitoring devices are also simulated, such as high and low pressure switches, user- and source-side water flow switches, and compressor thermal overload. These play a fundamental role, as in real units, in signaling any abnormal operation of the HVAC / R unit.

[0051] The second software module Virtual Loop complements the first software module Simulator: The first creates the physical variables as system outputs, based on the mathematical model; the second receives the variables as input, simulates the behavior of the software code as in a real control, and activates the actuators according to the control logic. The second software module Virtual Loop then reprocesses the status of the variables, considering the actuator status as input. The cycle repeats, generating a continuous system response.

[0052] The second software module Virtual Loop

[0053] Operating principle

[0054] The second software module Virtual Loop simulates the physical behavior of HVAC / R units based on predefined and configurable mathematical models. It receives the state of the actuators present in the HVAC / R unit as input data and recreates, based on boundary conditions, the physical variables present in the unit in response to the system.

[0055] Actuators, for example, include: compressor, expansion valve, circulation pumps, source fan, reverse cycle valves, etc.

[0056] The variables recreated include: suction and discharge pressures, suction and discharge temperatures, supply and return water temperatures, etc.

[0057] The main behaviors of the unit’s safety and monitoring devices are also simulated, such as high and low pressure switches, user- and source-side water flow switches, and compressor thermal cutout. These play a fundamental role, as in real units, in signaling any abnormal operation of the HVAC / R unit.

[0058] The second software module Virtual Loop complements the first software module Simulator: the first creates the physical quantities as system outputs, based on the mathematical model; the second receives the quantities as inputs, simulates the behavior of the software code as in a real control sy stem, and activates the actuators according to the control logic. The second software module Virtual Loop then reprocesses the state of the quantities, considering the state of the actuators as input. The cycle repeats, generating a continuous system response.

[0059] Setup

[0060] Setting up a simulation using the second software module Virtual Loop is called an experiment.

[0061] Correct configuration occurs through the following steps:

[0062] 1 . Selection of the unit type

[0063] 2. Unit configuration

[0064] 3. Virtual wiring

[0065] 4. Boundary conditions

[0066] Once the experiment is created, it can be saved and reopened later to run the simulation directly.

[0067] Selection of the unit type

[0068] The unit type is selected only when creating the experiment (Figure 3). The unit type encompasses a family of HVAC / 'R units composed of combinations of known options. Unit types include: residential heat pump, air conditioner, and commercial reversible chiller.

[0069] Each unit has a predefined set of available options, which, when combined, can generate different unit types.

[0070] The application of the unit's use is taken into account when developing the mathematical model. For example, the residential heat pump unit simulates the conditions in a (simplified) residential building. The internal temperature and humidity are available, and the model correlates these with the external temperature.

[0071] Unit Configuration

[0072] The unit configuration consists of three sections that allow to: select the machine options from the predefined ones (figure 3. A) and have direct feedback on the unit diagram (figure 3.B), change the sizing of the components (figure 3.C), and finally calibrate the safety devices (figure 3.D).

[0073] The selection of components for a residential heat pump unit includes the following options:

[0074] The various selected components modify the information required in the virtual wiring and boundary conditions. For example, selecting the water source allows for a specific return water temperature profile in the boundary conditions section.

[0075] The SIZING section (figure 3.C) is useful for correctly stimulating the software logic simulated by the first software module Simulator. In fact, a different sizing of the unit's components leads to a different plant equilibrium point. For example, an oversized electronic valve causes the unit., with the same PID parameters, to operate with more marked variations, stimulating certain protection functions such as low superheating.

[0076] Each component is compared to a unit with a nominal power of approximately 8 kW (Pdesign EN 14825 Cold climate). The load itself, i.e., the size of the building and its thermal insulation, was sized using an ideal coupling model.

[0077] The protection section allows to customize the activation thresholds for each protection:

[0078] • High and low pressure switches

[0079] • Antifreeze for user and source water

[0080] • User and source water flow switches

[0081] • Compressor thermal cutout

[0082] Note: When changing refrigerant, the activation thresholds for the pressure switches must be reconfigured.

[0083] Virtual Wiring

[0084] The virtual wiring creates a link between the information exchanged by the second software module Virtual Loop and the first software module Simulator. Communication between the two tools occurs via a standard communication protocol: Modbus.

[0085] The Modbus protocol, and the related serial communication port, are always present in HVAC / R unit software applications.

[0086] The first software module Simulator emulates the programmable control unit's serial port (like a real controller); in this case, the controller uses the Modbus Server protocol. The second software module Virtual Loop communicates on the same serial port, using the Modbus Client in a complementary' manner. The Modbus communication parameters (address and frame) are directly contained in the "RUN" section of the second software module Virtual Loop.

[0087] The virtual wiring consists of a structure that includes:

[0088] • PLC Variable: Describes the Modbus database, using a mnemonic string (typically the name of the variable itself). • Wiring: Contains the association of the exchange variables of the mathematical model with the controller, using the database described in PLC Variable.

[0089] PLC VARIABLE (figure 7.A)

[0090] The descriptor file can be imported and exported to customize the connection to controllers. It is a .csv file composed of the name (typically the variable), modbus data type, modbus address, size (1=16 bits, 2=32 bits), data type, and metadata describing whether the information is an input or output of the first software module Simulator.

[0091] Example:

[0092] Name, Register, Address, Size, Type, Purpose, RegisterType

[0093] DscgP,HoldingRegister,20010,2, REAL, INPUT, HOLDING REAL SuctP,HoldingRegister, 20022, 2, REAL, INPUT, HOLDING REAL

[0094] Wiring

[0095] Wiring is the association between the information available or required by the mathematical model. This can be done quickly from the user interface in the PLC To Model and Model To PLC sections. The first (figure 7.C) contains the information expected by the model (absence equals null / False), the second (figure 7.D) contains the information output to the first software module Simulator. Both sections can be imported / exported via the wiring import / export (figure 7.B).

[0096] "ModelToPlc" : {

[0097] "fini s compressor discharge temperature "DscgT",

[0098] "fini s compressor suction temperature "SuctT",

[0099] "fini s compressor thermal protection switch "RemAlrm ",

[0100] "fini s condensing _pressure gauge "DscgP ",

[0101] "ftni s domestic hot water reservoir temperature "DHW Storage ",

[0102] "fini s evaporating _pressure gauge "SuctP",

[0103] "fini s high _pressure switch "HiP Pstat ",

[0104] "fini s house internal humidity "ZoneHuml ",

[0105] "fini s house internal temperature": "ZoneTempl ",

[0106] "fini s low _pressure switch " Low P Pstat ",

[0107] "fini s outdoor temperature "ExtTemp ", "fini s user flow switch ": "MainWalerFlwSw ",

[0108] "fmi s waler return temperature ": "Waterin ",

[0109] "fmi s waler supply temperature ": "WaterOut"},

[0110] "PlcToModel" : {

[0111] "fini c compressor regulation percentage ": "Rotor SpeedP ere ",

[0112] "fmi c expansion valve regulation percentage ": "EEV PosPerc ",

[0113] "fini c four way valve opening signal": "RevVL V Circl ",

[0114] "fini c source device pegulation percentage ": "SrcFanSpeed",

[0115] "fmi c three way valve opening signal": "DELW PlantValve ",

[0116] "fmi c user device enabling signal" :"UsrPmpOnOff,

[0117] "fmi c user device regulation percentage ": "UsrPmpSpeed"}

[0118] The Model To PLC section contains more variables than those typically installed as inputs in physical controls; this allows for verification of more useful information during the simulation phase to analyze the correct operation of the refrigeration unit. For example, it is possible to verify the amount of ice deposited in the finned coil in the heat pump unit.

[0119] Virtual wiring also contains some special variables to facilitate starting the simulation.

[0120] • OnOff —» Control variable that turns the unit on / off

[0121] • Alarm Reset > Control variable for resetting alarms

[0122] • Simulation Flag Variable that the control can use to determine that the simulation is active. It is used to replace the physical signals of the connected probes with a virtual value sent by the second software module Virtual Loop.

[0123] They are recognized by replacing the parameter Purpose in the PLC VARIABLE descriptor with ON OFF, ALARM. RESET, SIMULATION. FLAG.

[0124] Example:

[0125] KeybOnOff Coil Status, 71, 1, BOOLEAN, ON OFF, COIL STA TVS

[0126] RES, CoilStatus, 72, 1, BOOLEAN, ALARM RESET, COIL STATUS

[0127] SIL Enable, CoilStatus, 20001, 1, BOOLEAN, SIMULA TION FLAG, COIL STA TUS

[0128] Boundary condition

[0129] These are the set of initial conditions (figure 9.C) and boundary conditions (figure 9. A) that describe the simulation’s execution perimeter. The choice of unit type (e.g., residential heat pump) and the configuration of the machine options determine the information needed for a correct simulation.

[0130] The initial conditions define the starting value at the simulation's zero point. In the case of the residential heat pump unit, the building and storage tank temperatures are subsequently recalculated as model output.

[0131] The boundary conditions, on the other hand, are information independent of the mathematical model; they are fixed or dynamic according to a profile that can be set via the user interface. The parameter to be set is selected (Figure 9. A) and the desired profile is created, considering that the entered data are interpolated. For example, it is possible to recreate a temperature profile for an Italian city in the month of January' (figure 9.B).

[0132] By customizing the boundary' conditions, it is possible to generate different plant responses. For example, it is possible to recreate the summer or winter operating conditions of a heat pump.

[0133] Starting the simulation

[0134] The complete simulation is performed by simultaneously starting the second software module Virtual Loop and the first software module Simulator with the software project you wish to analyze. Both tools should be configured consistently in terms of machine options.

[0135] After completing the initial setup, the simulation of the first software module Simulator is started and the RUN tab of the second software module Virtual Loop is accessed, the Modbus communication parameters (Figure 11. A), preconfigured for the applications developed by Card, are set and it is proceeded with the start by pressing RUN (figure l l.B). Figure 15 show's what appears on the user's display: a screen on the left — generated by the second software module Virtual Loop -representing the plant, and a screen on the right — generated by the first software module Simulator — with the programming interface showing the firmware code lines, which the programmer can edit and save.

[0136] In just a few seconds, the mathematical model resolves initial and boundary' states; the main variables are visible in the Modbus synoptic image (figure l l.C). Information is sent to the controller indicating that the simulation is active (SIMULA71C)NrFLAG) and the alarm reset command is sent. The simulation is therefore active.

[0137] To facilitate operational analysis, preconfigured graphs are available; simply click on the five main components: Compressor, Throttle Valve, ACS, Source and User Heat Exchangers (figure 11. H). It is also possible to create new customized graphs by multiple selection (CTRL) of variables from the Open Plots section (figure 1 l.F).

[0138] To facilitate startup operations, a control panel is available that directly acts on some commands made available by the controller (figure l l .D). This type of information has been mapped in the wiring (special functions) and does not pass through the mathematical model. The commands are: Alarm Reset, Unit On and Off.

[0139] There is also an Events panel (figure 11 ,E) where it is possible to enable disturbance events to the mathematical model, useful for stimulating anomalous behavior in the HVAC / R unit. For example, four events equivalent to a mechanical / electrical blockage of the four main devices: compressor, expansion valve, user pump, and source actuator. In this case, the active event requires the blocking position: e.g., expansion valve mechanically blocked at 20%, Another available event is the simulation of a refrigerant leak. The leak size must be configured based on the percentage of total charge / min. This last event allows to evaluate whether the control software algorithm responds correctly to a potential refrigerant leak.

[0140] Figure 12 shows an operating report of the plant, which depicts the plant and some physical parameter values detectable at certain points in the plant itself. With the graphical user interface of the second software module Virtual Loop it is possible to display time diagrams of the values of physical variables of the status of zones, as illustrated in figure 13, composing an operating report with the technical diagram of the plant and with these time diagrams, highlighted in the detailed view of figure 14.

[0141] If a programmer notices that the timing diagrams (figure 13) generated by the second software module Virtual Loop do not reflect the desired behavior, a programming interface in the first software module Simulator (figure 17) allows the firmware code to be modified in real time and saved as a modified version before simulating the operation of the plant again to verify whether the modified firmware version is capable of controlling the plant as desired. When this happens, the programmer has both the final firmware version ready to be loaded onto the control unit intended to govern a real- world HVAC plant, and a performance report — which the programmer can print from the first Virtual Loop software module's graphical user interface and / or save as a file to a mass memory — that can be distributed along with the firmware code to demonstrate that the firmware has been tested. The presence of timing diagrams in the performance report will allow the user of the real HVAC plant to verify that the firmware is capable of controlling the plant as desired, even under operating conditions that are difficult to safely replicate in a laboratory / .

Claims

CLAIMS1. A computer-implemented method of testing a firmware intended to be installed in a programmable control unit and of automatically generating an operation report of a simulation of a plant when said firmware is run, wherein said plant comprises an HVAC / R unit and mechanical components and is controlled by said programmable control unit that runs said firmware for implementing a control logic of the plant, wherein the method comprises the step of providing and installing on a computer a program comprising a software code that, when executed by the computer, generates on a screen of the computer a graphical user interface that has: a first section (A), configured to allow a user to select, from a menu, identifying information for an HVAC / R unit and mechanical components of a plant to be simulated, a second section (C, D), configured to allow the user to select sizes and operating parameters for the mechanical components, a third section (B), configured to display to the user a graphical image representative of the plant, a setup section configured to allow the user to set initial values of the plant and boundary / values of physical environmental parameters of an environment in which said plant is located; the method comprising performing the following operations with said computer: loading said firmware in an internal memory of the computer; displaying on said screen said graphical user interface; selecting, in said first, section (A), the HVAC / R unit and the mechanical components; selecting, in said second section (C, D), size and operating parameters of the mechanical components; inserting, in a space of the third section (B), graphic symbols that respectively represent the HVAC / R unit and the mechanical components, in which said graphicsymbols are depicted connected to each other as the HVAC / R unit and the mechanical components are connected in the plant; simulating an operation of the plant by calculating values of physical statequantities in zones of the simulated plant, wherein said physical state quantities evolve over time when the plant is in operation, based on mathematical models of operation of the HVAC / R unit and of operation of the mechanical components, based on how said graphic symbols are connected to each other in the graphic image, based on the initial values and said boundary' values of physical environmental parameters, and based on the control logic of the plant implemented by running said firmware by said programmable control unit; automatically generating said operation report, of the simulated plant, wherein the report includes at least the graphic image representing the simulated plant and includes said values of the physical state quantities superimposed on said graphic image in correspondence with said zones of the simulated plant; wherein the step of simulating a functioning of the plant comprises the following operations: with a first software module (Simulator), simulating the control logic of the plant, implemented by said programmable control unit when running said firmware, on the basis of said values of physical state quantities, and generating, by running said firmware in said first software module (Simulator), simulated commands for regulating the operation of the HVAC / R unit and of the mechanical components of the simulated plant; with a second software module (Virtual Loop), simulating an operation of said HVAC / R unit and of the mechanical components, wherein said second software module receives from said first software module (Simulator) said simulated commands for regulating the operation of the HVAC / R unit and of the mechanical components of the simulated plant, and calculates said values of the physical state quantities; wherein said firmware is distinct and separated from said second software module (Virtual Loop) and from said first software module (Simulator).

2. The method according to claim 1, further comprising the step of generating, with said computer, a programming interface for modifying a code of said firmware and for saving an updated version of the firmware before simulating again an operation of the plant.

3. The method according to one of the preceding claims, comprising the operation ofsetting, via said setting section, boundary values of air temperature and values of air humidity of the environment in which said plant is located.

4. The method according to one of the preceding claims, comprising: selecting, through said graphical user interface, a zone of said zones of the plant and displaying, following a selection of said zone, at least one time diagram of the values of physical state quantities in said zone; and inserting, in said automatically generated operation report of the plant, said at least one time diagram of the values of physical state quantities in said zone.

5. The method according to one of the preceding claims, comprising the steps of saving / loading, with said graphical user interface, information of said plant, wherein said information comprises said identifying information of the HVAC / R unit and of the mechanical components, said size and operating parameters of the mechanical components, said graphic image representing the plant.

6. The method according to one of the preceding claims, comprising the step of displaying on the screen or printing said operation report of the plant.

7. A computer program for testing a firmware intended to be installed in a programmable control unit and for automatically generating an operation report of a simulation of a plant when said firmware is run, wherein said plant comprises an HVAC / R unit and mechanical components and is controlled by said programmable control unit that runs said firmware for implementing a control logic of the plant, said program comprising a software code which, when executed by an electronic processor, causes the electronic processor:- to generate on a screen of the computer a graphical user interface that has: a first section (A), configured to allow a user to select, from a menu, identifying information for an HVAC / R unit and mechanical components of a plant to be simulated, a second section (C, D), configured to allow the user to select sizes and operating parameters for the mechanical components, a third section (B), configured to display to the user a graphical image representative of the plant, a setup section configured to allow the user to set initial values of the plantand boundary values of physical environmental parameters of an environment in which said plant is located;- to allow to perform the following operations with said computer: loading said firmware in an internal memory of the computer; displaying on said screen said graphical user interface; selecting, in said first section (A), the HVAC / R unit and the mechanical components; selecting, in said second section (C, D), size and operating parameters of the mechanical components; inserting, in a space of the third section (B), graphic symbols that respectively represent the HVAC / R unit and the mechanical components, in which said graphic symbols are depicted connected to each other as the HVAC / R unit and the mechanical components are connected in the plant; simulating an operation of the plant by calculating values of physical state quantities in zones of the simulated plant, wherein said physical state quantities evolve over time when the plant is in operation, based on mathematical models of operation of the HVAC / R unit and of operation of the mechanical components, based on how said graphic symbols are connected to each other in the graphic image, based on the initial values and said boundary values of physical environmental parameters, and based on the control logic of the plant implemented by running said firmware by said programmable control unit; automatically generating said operation report of the simulated plant, wherein the report includes at least the graphic image representing the simulated plant and includes said values of the physical state quantities superimposed on said graphic image in correspondence with said zones of the simulated plant; wherein said program further comprises a first software module (Simulator) for simulating a control logic of the plant, implemented by said programmable control unit when running said firmware, on the basis of said values of physical state quantities and for generating, by running said firmware with said first software module (Simulator), simulated commands for regulating the operation of the HVAC / R unit and of the mechanical components of thesimulated plant, a second software module (Virtual Loop) for simulating the operation of said HVAC / R. unit and of the mechanical components, wherein said second software module is configured to generate said graphical user interface and is configured to receive from said first software module (Simulator) said simulated commands for regulating the operation of the HVAC / R unit and of the mechanical components of the simulated plant and for calculating said values of the physical state quantities; wherein said firmware is distinct and separated from said second software module (Virtual Loop) and from said first software module (Simulator).

8. The program according to claim 7, wherein said first software module (Simulator) comprises a programming interface for modifying a code of said firmware and for saving an updated version of the firmware before simulating again an operation of the plant.

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