JP2002304433A - Simulation service system and recording media containing simulation service program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simulation service system which is applicable to new product development not affected by user environment by grasping the user's intention or the like. SOLUTION: A server machine 4 is provided with a simulation executing means for executing a simulation service relating to design assistance of electronic equipment, a holding means for holding simulation data, a sending means for generating and sending a screen for presenting a simulation list which can be executed to client machines 1 and 2 on the service user side, a receiving means for receiving simulation execution request information sent from the client machine, a commanding means for having simulation service using the simulation data executed by the simulation executing means based on the received simulation execution request information, and a notifying means for notifying the client machine requesting the simulation of a result of simulation executed in response to a command of the commanding means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a simulation service system and a recording medium storing a simulation service program. More specifically, the present invention relates to a simulation service system for providing a design support service such as an EMI (Electro Magnetic Interference) simulator on a network infrastructure such as the Internet, and a recording medium storing a simulation service program.

[0002]

2. Description of the Related Art The use of a transmission line / EMI simulator is indispensable when designing electronic equipment, especially high-speed digital equipment. This is in order to avoid unnecessary production of prototypes by taking appropriate EMI measures. As such an EMI simulator, “Equivalent circuit of inductance element, method of analyzing circuit constant, simulator and recording medium” (Japanese Patent Application Laid-Open No. H11-321187) proposed by the present inventors has been known. This known technique relates to a high-precision equivalent circuit and an analysis method capable of favorably expressing the characteristics of an inductance element using a ferrite material (hereinafter, simply referred to as “inductance element”). The present invention relates to an inductance element inserted into a signal line or a power supply line of an electronic device to prevent EMI.

[0003] In general, an equivalent circuit of this kind of inductance element has conventionally been represented as a circuit in which an inductance (Lp), a capacitance (Cp) and a resistance (Rp) are connected in parallel, a so-called "LpCpRp parallel equivalent circuit". However, there is a disadvantage that sufficient accuracy cannot be obtained when used for simulation. In other words, the designer selects an appropriate one from various commercially available inductance elements and incorporates it into the electronic device designed by him / her to perform EMI countermeasures. A simulation (inductance element) with the intended simulation results must be obtained by trying a simulation using the equivalent circuit of the above, but if the accuracy of the simulation is low, the required This is because the EMI suppression effect cannot be obtained.

According to the equivalent circuit improved by the above-mentioned known technique, sufficient simulation accuracy can be obtained, so that there is no such inconvenience and the product (inductance element)
The certainty of the selection can be improved.

[0005]

However, the above-mentioned known technology is characterized in that the characteristics of an inductance element using a ferrite material can be expressed well, and a highly accurate equivalent circuit and analysis method can be provided. Although useful, the designer has assumed that only simulations that are executed in a so-called "stand-alone" manner have the following problems.

(1) A person who does not have a stand-alone execution environment, or who does not have a simulation program to which the above-described known technique is applied, does not receive any merit. (2) When the simulation program to which the analysis method of the above-mentioned known technology is applied is improved, or when a new equivalent circuit or a corresponding product (such as an inductance element) is added, the version of the program or data is updated each time. It has to be up and it takes time. (3) From the viewpoint of a company that manufactures products such as inductance elements, it is difficult to grasp the wishes and intentions of the user (designer, etc.), and it cannot be used for new product development.

Therefore, the ultimate object of the present invention is to develop a new product without being affected by the user environment, without requiring the user to upgrade the program or the like, and by grasping the intention of the user. An object of the present invention is to provide a simulation service system that can be used for a computer.

[0008]

In order to achieve the above object, the present invention provides a simulation executing means for executing a simulation service related to design support of an electronic device, and a holding means for holding simulation data required for the simulation service. Means, transmission means for generating and transmitting a simulation list screen for presenting an executable simulation list to the service user side client machine, and simulation execution request information transmitted from the service user side client machine Receiving means for receiving, fetching simulation data required for the simulation service from the holding means based on the simulation execution request information received by the receiving means, and using the simulation data And instruction means for executing the simulation service by the simulation execution unit has,
And a notifying unit for receiving a simulation result executed in response to the instruction from the instructing unit from the simulation executing unit and notifying the simulation result requesting service user side client machine. Further, the preferred embodiment is,
The server machine is characterized in that the simulation data held in the holding means can be registered via the network. In the present invention, a simulation list screen for presenting a simulation list executable on the server machine is transmitted to the service user side client machine.
When receiving the simulation execution request information transmitted from the service user side client machine, the simulation data necessary for the simulation service is extracted from the holding unit based on the simulation execution request information, and the simulation data is used. The simulation service is executed by the simulation executing means, and the result of the simulation is notified to the service user side client machine requesting the simulation.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, the system configuration of the present embodiment will be described. FIG. 1 is a conceptual diagram of a system configuration. FIG. 1 schematically shows a state in which a client machine group 1 or 2 divided into two is connected to a server machine 4 on a network 3. I have.

The server machine 4 executes the simulation service in the present embodiment, and the client machines 1a to 1c and 2a to 2c constituting the two client machine groups 1 and 2 are individually Can use the simulation service.

The simulation service of the present embodiment provides a simulation service such as an EMI simulator to one client machine group 1 and the other client machine group 2
For this purpose, a registration service of various data used in the simulation service, for example, equivalent circuit data in the above-described conventional technology is provided. In this case, each of the client machines 1a to 1c constituting one client machine group 1 is installed near a designer or the like (hereinafter, referred to as a "user") using a simulation service, and the other client machine group 2 is connected to the other. Each of the constituent client machines 2a to 2c is installed, for example, in the vicinity of a person in charge of a manufacturer of an inductance element using a ferrite material.

Hereinafter, two client machine groups 1, 2
In order to distinguish between the two, one client machine group 1 is referred to as “service user side client machine group 1”,
The other client machine group 2 is referred to as a “data provider client machine group 2”, and the client machines 1a to 1c constituting the service user client machine group 1 are referred to as “service user client machines 1a to 1c”. 1c ", and the client machines 2a to 2c constituting the data provider side client machine group 2 are referred to as" data provider side client machines 2a to 2c ".

Here, the client machines 1a to 1c,
When the functions to be provided are defined for each of the networks 2a to 2c, the network 3, and the server machine 4, first, the server machine 4 must have a function as a so-called Web (Web) server. A required simulation service is executed using this web server function. On the other hand, client machines 1a-1c, 2a-2c
Needs only to have a function of accessing the above-mentioned web server via the network 3. In this respect,
It is preferable to use a general-purpose personal computer equipped with browser software or a network OS (operating system), a dedicated word processor, a portable information terminal, or the like. This is because anyone can easily obtain the content and freely browse the content on the web server by connecting to the network 3.

The network 3 must enable communication between at least the client machines 1a to 1c and 2a to 2c and the server machine 4. In general, the de facto standard of the network protocol is today. , Internet Protocol (I
P), and the majority of general-purpose personal computers, various server machines, and the like support this IP, so that the network 3 may be virtually any IP-compatible so-called “Internet”. Note that the Internet does not physically exist. It is a general term for IP-compatible communication media such as a backbone connecting Internet Service Providers (ISPs) and a subscriber line (or cable television line or wireless line) connecting the ISP to a subscriber's home.

Next, the server machine 4 has various functional units for realizing the above-described simulation service and data registration service on the network 3. These functional units are realized by an organic combination of software resources such as an operating system and various application programs executed on the server machine 4 and hardware resources of the server machine 4. If separated, for example, the communication unit 4a, the user management unit 4b, the simulation reception unit 4c, the simulation execution unit 4d, the simulation result notification unit 4
e, the database 4f, the simulation data registration unit 4g, and the like.

That is, the communication unit 4 a
The user management unit 4b controls the communication between the client machines 1a and 1c and the client machines 1a to 1c and 2a to 2c constituting the client machine groups 1 and 2 through The simulation accepting unit 4c accepts a simulation service use request from the service user side client machines 1a to 1c, and the simulation executing unit 4d executes the requested simulation service. In addition, the simulation result notifying unit 4e notifies the service execution side client machines 1a to 1c of the simulation execution result. The database 4f holds user management data, simulation data, and the like. Further, the simulation data registration unit 4g stores
For example, it receives equivalent circuit data and the like necessary for the EMI simulator from the data provider side client machines 2a to 2c and registers them in the database 4f.

Next, an outline of the operation model of the above system configuration will be described. FIG. 2 is a flow chart (time run), in which information exchange between the service user side client machine group 1 and the server machine 4 is shown over time.

First, the operator of the service user-side client machine group 1 performs user registration with the server machine 4 to receive the simulation service. This registration operation is executed by the user management unit 4b of the server machine 4, and the user management unit 4b transmits a predetermined user registration screen to the client machine requesting the registration, and receives the user information input on the registration screen. In addition to performing a procedure of registering in the database 4f, a user registration notification screen describing unique authentication information (ID, password, etc.) for each registered user is transmitted to the client machine that has issued the registration request.

FIG. 3 shows an example of a user registration screen and a user notification screen. In this figure, a user registration screen 10 has an appropriate title character string ("user registration" in the figure) display area 10a, a text box control 10b for entering a company name, a text box control 10c for entering a person in charge, and an address. It has a user information input area such as an input text box control 10d, an e-mail address (Email) input text box control 10e, and the like. URL; Unif
orm Resource Locator) and a cancel command button control 10g for canceling input information.

On the other hand, the user registration notification screen 11 has an appropriate title character string ("user registration notification" in the figure) display area 11a, a company name display text box control 11b, and a person name display text box control. 11c, a text box control for address display 11d, a text box control for e-mail address display 11e, etc., and a unique authentication information for each registered user, that is, a text box control for ID display 11f. And a text box control 11g for displaying a password.

According to the user registration screen 10 and the user registration notification screen 11, an arbitrary client machine of the client machine group 1 accesses the server machine 4, receives the user registration screen 10, and displays the user registration screen on the client machine. The required user information (company name, person in charge, address, e-mail address,
・), And send command button control 10
By clicking f, a user registration that transmits the input information to the server machine 4, performs user registration in the user management unit 4b of the server machine 4, and transmits a registration notification from the server machine 4 to the client machine This can be performed by the screen 11.

Therefore, only the authenticated user can be permitted to use the EMI simulation service, for example, and the use record and data registration record can be grasped by the server machine 4, and the use charge of the simulation service is collected. And a data registration fee can be collected, so that the simulation service can be operated for a fee and a profit base can be secured, and a stable business model can be constructed.

After completing the user registration, the user of the simulation service operates any client machine of the client machine group 1 at any time to provide the server machine 4 with services such as EMI simulation. Can be requested. That is,
The authorized user first accesses the server machine 4 from the client machine and requests a simulation list. In this case, the server machine 4 performs an authentication process using an ID or a password to determine whether or not the user is an authorized user. If the user is an authorized user, the simulation receiving unit 4c of the server machine 4 transmits a predetermined simulation list screen covering simulation items that can be executed by the simulation service to the requesting client machine.

FIG. 4 is a diagram showing an example of the simulation list screen. Simulation list screen 12
Has an appropriate title character string ("simulation list" in the figure) display area 12a and a list area 12b covering simulation items that can be executed by the simulation service. In the illustrated example, for example, One simulation classification item “EMI noise countermeasures” and one simulation execution item “Ferrite chip beads” included in the classification item are typically shown.

Here, the ferrite chip bead is an inductance element using a ferrite material, and is a component that is inserted into a signal line or a power supply line of an electronic device to prevent EMI noise. is there.
There are several products that are suitable for the used frequency, signal band, etc., and it is necessary to select an appropriate product based on the results of the simulation.

In the following, an EMI simulation performed on ferrite chip beads will be described as an example. First, a legitimate user first selects “ferrite chip beads” on the simulation list screen 12 displayed on the screen of the client machine. Click the item. In response, the client machine sends the server machine 4
Of the “ferrite chip / bead” is instructed to the simulation execution unit 4d, and the simulation execution unit 4d specifies a part number of the “ferrite chip / bead” (and specifies a simulation parameter if necessary). (For convenience) is generated and transmitted to the client machine.

FIG. 5 is a diagram showing an example of a part number selection screen. In this figure, the part number selection screen 13 has an appropriate title character string ("part number selection" in the figure) display area 13a and an equivalent circuit used for simulation (an equivalent circuit of "ferrite chip beads" in the figure).
Display area 13b, list box control 13c for part number selection, and transmission command button control 13d
And a parameter input area (not shown) for designating simulation parameters if necessary.

Here, the equivalent circuit shown in FIG.
This is an improvement on the pCpRp equivalent circuit. That is,
The parallel equivalent circuit of the inductance Lp (“Ls” in the figure), the capacitance Cp, and the resistance Rp is improved as follows.

(A) A first circuit in which a resistance Rm2 and an inductance Lm2 are connected in parallel and resistances RT1 and RT2 are connected in series at both ends thereof is connected in parallel to a conventionally known LpCpRp equivalent circuit, and Lm2 and Ls are magnetically coupled by M2. (B) A resistance Rm1 and an inductance Lm1 are connected in parallel, and a second circuit formed by connecting resistances RT3 and RT4 in series at both ends thereof is connected in parallel to a conventionally known LpCpRp equivalent circuit.
m1 and Ls are magnetically coupled at M1. (C) The inductance Lr is connected in parallel with Rp, and the capacitance Cr is connected in series with Rp. (D) A resistance R is provided at one end of the LpCpRp equivalent circuit.
Insert s.

However, RT1, RT2, RT3 and RT
4 is a fixed value (for example, 1000Ω), and other parameters (Rs, Rm1, Rm2, Lm1, Lm2,
Ls, Cp, Rp, Lr, and Cr) are set to values preset for each product number. The magnetic coupling coefficient M1 is given by a value obtained by multiplying the square root of the product of Ls and Lm1 by a coefficient K1 preset for each product number.
The magnetic coupling coefficient M2 is also given as a value obtained by multiplying the square root of the product of Ls and Lm2 by a coefficient K2 preset for each product number.

In the part number selection screen 13 shown in the figure, the part number selection text box control 13c has
The product number “BK1005HS121” is displayed. E using this type of ferrite chip beads
When executing the MI simulation, the transmission command button control 13d may be clicked as it is. Alternatively, if you want to change to another part number, click the button on the right end of the part number selection text box control 13c (button displaying an inverted triangle figure) to display the part number list, and select the desired part number from the list. Then, the transmission command button control 13d may be clicked. In any case, when designating a simulation parameter such as a signal frequency, an appropriate parameter is input to a parameter input area (not shown) provided on the product number selection screen 13.

When the transmission command button control 13d is clicked, the part number information and the simulation parameter data are transmitted to the server machine 4, and the simulation is executed by the simulation execution unit 4d of the server machine 4. Then, with the completion of the simulation, a screen showing the simulation result is generated by the simulation result notifying unit 4E, and is returned to the client machine that requested the simulation. The simulation algorithm executed in the simulation execution unit 4d is not particularly limited. For example, an analysis method described in Japanese Patent Application Laid-Open No. H11-212187 may be applied, or another known simulation algorithm may be applied.

FIG. 6 is a diagram showing an example of the simulation result notification screen. In this figure, the simulation result notification screen 14 is divided into several areas. Hereinafter, for convenience, each of the regions is referred to as a region A to a region E, and the region A displays a product number, a size, an electrical characteristic, and the like of the inductance element. For example, FIG.
As shown in (a), a part number (Selection Parts), a height of parts (Height), a DC resistance value (DC resistance), a rated current (Rated current), and the like are displayed.

The area B displays a simulation parameter, for example, an input signal condition as shown in FIG. 7B. In the region C, as shown in FIG. 8A, for example, as shown in FIG. 8A, the characteristics of the resistance component R, the reactance component X, and the combined impedance Z in a two-dimensional graph in which the horizontal axis represents frequency and the vertical axis represents impedance. indicate.

The region D displays a signal waveform diagram, for example, a signal waveform diagram for comparing and comparing the signal waveform before the EMI measure and the signal waveform after the measure as shown in FIG. 8B. The region E displays a signal current spectrum, for example, a signal current spectrum for comparing and comparing the signal current spectrum before the EMI measure and the signal current spectrum after the measure as shown in FIG.

The simulation result notification screen 14
According to the above, when the ferrite chip beads of the product number displayed in the area A are used, the impedance characteristics when the simulation parameters displayed in the area B are given can be known from the display of the area C. The signal waveform in which the EMI noise is suppressed can be known from the display of the region D, and the spectrum of the signal current can be known from the display of the region E. Therefore, if the desired simulation result has been obtained, the ferrite chip / bead of that part number may be obtained, or if not obtained, the part number may be changed until the desired simulation result is obtained. Then, the simulation may be repeatedly executed.

As described above, according to the present embodiment, the service user side client machines 1a to 1
c, the user can access the server machine 4 at any time and receive a simulation service such as an EMI simulation, so that the user possesses a client machine connectable to the network 3 and completes a predetermined user registration. Anyone can freely receive the simulation service.

The simulation program is a server-side program executed on the server machine 4, and transmits only the execution result to the client machine. Therefore, even when the simulation program is improved, the simulation program is sent to the client machine side. Does not require any work, and does not impose a burden on the user side.

Further, since the contents of the simulation for each user can be accurately grasped by the server machine 4, the simulation history can be collected and analyzed, so that it can be used as material for new product development and the like, and can be directly transmitted to the user. It is possible to obtain various advantages such that it is possible to carry out various sales promotion activities and the like.

It is needless to say that data such as an equivalent circuit and an analysis algorithm necessary for the simulation are registered in advance in the database 4f of the server machine 4, but this registration procedure is performed via the network 3. It is preferable to be able to do it remotely.

FIG. 10 is a conceptual diagram of a table configuration of the database 4f. The database 4f stores parameters (Rs, Cp, Rp, Lr, Cr, R
m1, Rm2, Ls, Lm1, Lm2, K1, K2,.
・ ・) Is composed of a part number record consisting of a plurality of fields for storing
As shown in FIG. 11, the product number “BK1005HS121”
For Rs = “0.10”, Cp = “0.3
0, Rp = “160”, Lr = “1E + 101”, C
r = “1E + 101”, Rm1 = “160”, Rm2 =
“1”, La = “0.65”, Lm1 = “0.65”,
Lm2 = “1”, K1 = “0.70”, and K2 =
The data such as "0" is the same as the product number "BK1005HS"
241 ”, Rs =“ 0.20 ”, Cp =
“0.33”, Rp = “330”, Lr = “1E + 10”
1 ", Cr =" 1E + 101 ", Rm1 =" 350 ",
Rm2 = "1", La = "1.05", Lm1 = "1.
05 ", Lm2 =" 1 ", K1 =" 0.67 ", and
Data such as K2 = "0" is stored in advance.

Here, the data of the product number specified by the product number selection list box control 13c provided on the product number selection screen 13 of FIG. 5 is, for example, "BK1005H
In the case of S121 ", the simulation execution unit 4d of the server machine 4 executes the simulation using the data stored in the corresponding record (the first record in FIG. 11) of the database 4f. B
If the data of "K1005HS241" is record data newly added to the database 4f via the network 3, the data of the new record is immediately displayed on the list box control 13c for part number selection and becomes selectable. By selecting the data of the new record (data of the product number “BK1005HS241”), a simulation using the data of the new record can be executed.

That is, as shown in FIG. 12, a data provider-side client machine group 2 installed in a company that manufactures products such as ferrite chips and beads sends a user management unit 4b of a server machine 4 to a user management unit 4b in advance. In addition, when a new product is manufactured, simulation data (equivalent circuit, parameter, etc.) relating to the product is transmitted to the server machine 4 and the simulation data registration unit 4g of the server machine 4 By simply additionally registering as a new record in the database 4f, a simulation service for such a new product can be promptly provided.

[0044]

According to the present invention, a simulation list screen for presenting a simulation list executable on a server machine is transmitted to a client machine on the service user side. When receiving the simulation execution request information transmitted from the service user side client machine, the simulation data necessary for the simulation service is extracted from the holding unit based on the simulation execution request information, and the simulation data is used. The simulation service is executed by the simulation executing means, and the result of the simulation is notified to the service user side client machine requesting the simulation. Therefore, it is possible to freely receive a desired simulation service via a network, and to obtain the simulation result promptly, without being affected by the user environment. In addition, the user needs to upgrade a program or the like. It is possible to provide a simulation service that can utilize the history information for new product development because it is possible to realize a simulation service that does not require the use of the service information and to grasp the use history of the service on the server machine.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a system configuration according to an embodiment.

FIG. 2 is a flowchart showing an operation model according to the embodiment.

FIG. 3 is a diagram showing an example of a user registration screen 10 and a user notification screen 11;

FIG. 4 is a diagram showing an example of a simulation list screen 12;

FIG. 5 is a diagram showing an example of a part number selection screen 13;

FIG. 6 is a diagram illustrating an example of a simulation result notification screen 14;

FIG. 7 is a diagram showing an area A and an area B of the simulation result notification screen 14.

FIG. 8 is a diagram showing a region C and a region D of the simulation result notification screen 14.

FIG. 9 is a diagram showing an area E of a simulation result notification screen 14;

FIG. 10 is a conceptual diagram of a table configuration of a database 4f.

FIG. 11 is a diagram showing an example of actual record data of a database 4f.

FIG. 12 is a flowchart showing registration of simulation data.

[Explanation of symbols]

1a to 1c Client machine (service user side client machine) 4 Server machine 4c Simulation reception unit (transmission unit) 4d Simulation execution unit (simulation execution unit, reception unit, command unit) 4e Simulation result notification unit (notification unit) 4f database (Holding means) 12 Simulation list screen

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuru Segawa 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Electric Power Co., Inc. (72) Yoshiaki Sato 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Induction Co., Ltd. (72) Inventor Kenichi Hattori 6-16-20 Ueno, Taito-ku, Tokyo Taiboku Induction Co., Ltd. F-term (reference) 5B046 AA08 BA04 CA06 DA01 GA01 JA04 KA05 5E501 AC09 AC17 AC36 BA03 DA02 EA15 FA08 FA14

Claims (4)

[Claims] 1. A server machine and a client machine that can communicate with each other through a network. 1) The server machine includes: a simulation execution unit that executes a simulation service related to design support of an electronic device; Holding means for holding simulation data necessary for the operation, a transmission means for generating and transmitting a simulation list screen for presenting an executable simulation list to the client machine on the service user side, and a service user side Receiving means for receiving simulation execution request information transmitted from the client machine; and simulation data required for the simulation service based on the simulation execution request information received by the receiving means. Command means for taking out from the holding means and causing the simulation execution means to execute a simulation service using the simulation data; and receiving a simulation result executed in response to a command from the command means from the simulation execution means and performing a simulation. Notifying means for notifying the requesting service user client machine; 2) The client machine requests a simulation list screen for accessing the server machine and presenting a simulation list executable on the server machine. Selecting means for selecting a desired simulation service from a simulation list screen transmitted from the server machine in response to the request; and selecting means selected by the selecting means. Simulation service system characterized by a transmission means for transmitting the simulation execution request information to the server machine. 2. A simulation execution unit for executing a simulation service related to design support of an electronic device, a holding unit for holding simulation data required for the simulation service, and a simulation executable for a client machine on a service user side. Transmitting means for generating and transmitting a simulation list screen for presenting a list; receiving means for receiving simulation execution request information transmitted from the client machine on the service user side; and simulation execution request received by the receiving means The simulation data required for the simulation service is retrieved from the holding unit based on the information, and the simulation service using the simulation data is executed by the simulation. A server having command means to be executed by an execution means; and notification means for receiving a simulation result executed in response to the command from the command means from the simulation execution means and notifying the simulation result requesting service user side client machine. A simulation service system comprising a machine. 3. The server machine according to claim 1, wherein the server machine is configured to be able to register the simulation data held in the holding unit via the network. Simulation service system. 4. A simulation executing means for executing a simulation service related to electronic equipment design support,
Holding means for holding simulation data necessary for the simulation service, transmitting means for generating and transmitting a simulation list screen for presenting an executable simulation list to a service user side client machine, and a service user side client Receiving means for receiving the simulation execution request information transmitted from the machine, extracting simulation data required for the simulation service from the holding means based on the simulation execution request information received by the reception means, and using the simulation data; Command means for causing a simulation service to be executed by the simulation executing means; and a simulation result executed in response to a command from the command means. Recording medium storing a simulation service program for realizing all or a part of the means of notifying means for notifying the simulation requesting service side client machine receives from the execution unit.