201214131 六、發明說明： 【發明所屬之技術領域】 本發明是關於一種遠端資料傳輪方法及使用此方法的虛 擬媒體系統；具體而言’本發明是關於一種可避免資料傳輸 - 延遲所造成的通用序列匯流排之超時重置的遠端資料傳輸方 ， 法’以及使用此遠端資料傳輸方法的虛擬媒體系統。 • 【先前技術】 虛擬媒體是一種將例如光碟機、硬碟機等實體或虛擬的客 戶端媒體設備連接至伺服器端電腦，而使伺服器端電腦得以 存取自身實體媒體的方式來存取客戶端媒體設備的方法。 對於網路管理員等需要管理大量電腦的人而言，由於伺服 器端電腦可以如同使用自身實體媒體一般地利用虛擬媒體來 進行軟體女裝，甚至是利用虛擬媒體來開機，以完成作業系 % 統或應用程式等軟體的安裝或病毒掃描等工作，因此其便利 性可見一斑。 由於通用序列匯流排（Universal Serial Bus，USB )介面可 提供許多強大的魏，再加上其使壯的方便性，—般虛擬 媒體系統的飼服器端電腦多以通用序列匯流排作為其連接介 面。第1A圖為習知的虛擬媒體系統的示意圖。如第1A圖所 不，伺服器端1的主機單元2與虛擬媒體單元3之間藉由通 =序列匯流排4相連接，虛擬媒體單元3與客戶端5之間則 藉由網路6相連接。藉由虛擬媒體單元3的連接，主機單元 201214131 二::用存取通用序列匯流排裝置的方式與客戶端 體°又備進仃通訊，進而存取其中的媒體資料。 、 音圖第= 第，示虛擬媒體系統傳輸資料成功的示 s月求㈣"1的:#料财），助應地使㈣w (C()mmand S_s Wrapper，指令狀態封包）來發送狀態應答(如指令^ 執灯成功)。本例由於在2秒軸應答時限内收到指令 成功的指令狀態塊封包，因崎料傳輸成功。 然而’在通用序列匯流排協定中，通用序列匯流主雖 在對通用序列匯流難置發出請求後超過應答時限伽 而未收到顧序舰流贼㈣雜應答時，會對該通用庠 列匯流排裝置進行重置(则)，而資料在網路中傳輸的過程中 往往會因為網路頻寬不足、傳輸距離過長或網路壅塞等因素 而造成傳輸的觀’因脸機單讀趣媒辟元之間的連 接往往會因為虛擬媒體單元與客戶端之間的網路的連接問題 而中斷。 :第1C圖及1D圖為第1A圖所示虛擬媒體系統的兩種傳輸 資料失敗之狀況的示_。如第lc _示，由於主機單元 未在2秒鐘的應答時關收職示指令丨執行成功的指令狀 態塊封包，因此指令1的資料請求被視為失敗。如第圖 所示，雖鉢戶端已將所有資料_給顧聰單元，但由 於主機單元未在2秒鐘的應答時限隨到絲齡丨執行成 201214131 功的指令狀態塊封包’因此指令1的資料請求被視為失敗。 此兩種情況發生時主機單元皆會對虛擬媒體單元進行重置， 使得指令1的資料傳輸操作必須整個重來，浪費的是時間與 頻寬等成本。猶有甚者，在網路狀況較差的情況下，甚至會 反覆進行重置而使得資料傳輸等操作最終不能完成。 【發明内容】 本發明的目的在於提供一種遠端資料傳輸方法及使用此 方法的虛擬媒體系統，相較於先前技術，可避免資料傳輸延 遲所造成的通用序列匯流排的超時重置。 本發明的遠端資料傳輸方法用於伺服器端及客戶端之 間，伺服器端包含主機單元及虛擬媒體單元。虛擬媒體單元 以通用序龜流娜定與域單元進行通訊，而域單元對 虛擬媒體單元發出的請求具有應答時限。此遠端資料傳輸方 法包括下列步驟：（a)主機單元發送資料請求至虚擬媒體單 元，0)虛擬媒體單元根據資料請求要求客戶端傳輸資料；⑷ 判斷應答時限結束前的預留期間是否已屆至·，⑹若預留期間 未屆至斷虛減體單元是否已輯龍請求完成資料 的接收，若已完成接收則將資料傳輸至主機單元，若未完成 接收則繼、，、！自客戶端接收資料，並回到步驟⑷；&读預留期 =已屆至，則虛擬媒體單元驅使主機單元執行延遲程序並取 得自身媒财置的狀態，虛擬媒體單元同時自客戶端接收資 料’而後頌單元賴發送簡請求結擬舰單元，然後 回到步驟(e)。本發明遠端資料傳輸方法延遲程序的機制 201214131 來避免虛㈣體單元與客戶端之間的㈣傳輸延遲造成主機 單元與虛擬媒體單元之間的通訊被重置。 本發明虛擬賴系統包含主機單元、顧序舰流排單元 及虛擬媒體單元。虛擬媒體單元經由序顺流排單元與 主機單元進行通訊。域單元對虛擬舰單元發出請求後經 過應答時_未完絲答程料，與虛擬·單元之間的通 訊會被重置。其中當虛擬媒體單元自主機單元收到一個新的 資料請求時，據以要求客戶端傳輸資料並加以接收；在應答 時限結束前的預留期間屆至前，若虛擬媒體單元已根據資料 請求完成資料的接收，則將資料傳輸至主機單元，否則繼續 自客戶端接收資料；在預留期間屆至後，主機單元被虛擬媒 體單元驅使進入執行延遲程序，虛擬媒體單元同時自客戶端 接收資料，而後主機單元重新發送資料請求至虛擬媒體單 元。本發明虛擬媒體系統利用虛擬媒體單元驅使主機單元進 入執行延遲程序的機制來避免虛擬媒體單元與客戶端之間的 資料傳輸延遲造成主機單元與虛擬媒體單元之間的通訊被重 置。 【實施方式】 本發明提供一種遠端資料傳輸方法及使用此方法的虛擬 媒體系統。在較佳實施例中，本發明的遠端資料傳輸方法使 用於虛擬媒體系統或虛擬媒體裝置中。然而在其他實施例 中’本發明的遠端資料傳輸方法可使用於其他類型的系統或 裝置中。 201214131 第2圖為本發明遠端資料傳輸方法的一實施例的示意圖； 第3A圖為本發明虛擬媒體系統的一實施例的示意圖。如第 3A圖所示’此虛擬媒體系統包含伺服器端10及客戶端20， 伺服器端10包含主機單元11及虛擬媒體單元12，第2圖的 遠端資料傳輸方法可用於主機單元11、虛擬媒體單元12及 客戶端20。主機單元11與虛擬媒體單元12之間以通用序列 匯流排單元13連接，亦即以通用序列匯流排協定進行通訊。 其中主機單元11為通用序列匯流排主機(h〇st)，虛擬媒體單 元12則為通用序列匯流排裝置。在本實施例中，虛擬媒體單 元12與客戶端20之間係藉由乙太網路(Ethemet)30來連接； 然而在其他實施例中，可藉由其他類型的網路或其他裝置來 連接。 第3B圖為第3A圖所示虛擬媒體系統使用第2圖所示遠 端資料傳輸方法的一實施例的示意圖。如第3B圖所示，主 =單元使雌述的CBW來發送齡·(例如指令〗的資料 請求），虛擬媒體單元則相應地使用前述的csw來發送狀態 應答(例如指令1執行失敗)。由於在通用序列匯流排協定中， 通用序列匯流排主機對通用序列匯流排裝置發出的請求具有 應答時限，gl此當域單元對虛擬舰單元發出請求後， ，過應答日植Tl (在本實關中為2秒）岐㈣虛擬媒體 早疋的狀態應答時’域單元會重置與虛擬媒體單元之間的 連接。 如第2圖及第3B圖所示，此遠端資料傳輸方法包括下列 步驟：在步驟m巾’域單元發送娜f求域擬媒體單 201214131 元。在較佳實施例中，此資料請求係使用CBW來發送。在 步驟120中’虛_體單元根據資料請求要求客戶端傳輸資 料至虛擬雜單。在本實關巾’㈣本實關的虛擬媒 體單兀與客戶端之間藉由乙太網路相連接，因此資料請求係 使用乙太網路封包(例如Tcp/ip封包)來發送。 在步驟130中’主機單元判斷應答時限結束前的預留期間 A是否已屆至。預留期間&為長度小於應答時限Τι的一段 時間’其長度較佳大於虛擬媒體單元對主機單元發送csw 加上主機單兀對虛擬媒體單元發送CBW所需的時間，使得 主機單元在收到虛擬媒體單元的狀態應答後有足夠的時間發 送指令請求至虛擬媒體單元以作為反應。 若預留期間T2已屆至，表示主機單元不可能在應答時限 Τ!結束前收到虛擬媒體單元的狀態應答並作出反應，則在步 驟170令，虛擬媒體單元驅使主機單元進入延遲程序並取得 虛擬媒體單元的狀態，虛擬媒體單元同時自客戶端接收資 料’而後主機單元重新發送資料請求至虛擬媒辟元，然後 回到步驟1如。第4圖為第2圖所示遠端資料傳輸方法中的 延遲耘序的一貫施例的示意圖。如第4圖及第3B圖所示， 在較佳實施例中，第2圖所示的步驟17〇包含：在步驟171 中，若預留期間已屆至，則虛擬媒體單元發送相應於資料請 求的指令失敗應答至主機單元。虛擬媒體單元以發送指令失 敗應答的方式來驅使主機單元進入延遲程序。在較佳實施例 中，指令失敗應答係使用CSW來發送。在步驟172中，當 主機單元收到指令失敗應答時，發送包含要求虛擬媒體單"元 201214131 回報錯誤資訊的設備狀態請求至虛擬媒體單元。此步驟為延 遲程序的兩個步驟中的第一個。主機單元發送設備狀態請求 的真正目的並不是要使虛擬媒體單元回報設備狀態，而是用 來使主機單元相應地進行等待。在較佳實施例中，係使用 CBW來發送操作碼(operati〇n code，〇pc〇de)為加〇3(即代叫咖 sense)的指令，以要求虛擬媒體單元回報包含錯誤資訊的感測 • 資料(sense data)。 • 感測^料中包含鍵碼限定符(Key Code Qualifier，KCQ)錯 誤碼。表1為鍵碼限定符錯誤碼的值列表，鍵碼限定符錯誤 碼包含二個攔位.識別鍵欄(sense key fieid)、額外識別碼 (additional sense code ’ ASC)攔以及額外識別碼限定符 Odditional sense eode qualifier ’ ASCQ)攔。在較佳實施例中， 識別鍵攔的值(value)為〇2h，額外識別碼欄的值為0处，額外 識別碼限定符襴的侧為Glh，以表示虛擬單元即將處 於可用的狀態’使主機單元可相應地進行等待；然而在其他 • 實施例中，上述攔位可以為表1所列的其他值、其他可用於 请求虛擬媒體單元之設備狀態的值或其他可使主機單 地進行等待的值。 ~ 表1 ------ 今、上 _____限定符錯誤碼 識別鍵 __^卜識別碼 額外識別碼限定符 02h 〇4h ----—, 一 Olh 02h 〇4h ---— 09h 02h 04h —-— 07h — —... 201214131 ~~~— 在V驟173中，虽虛擬媒體單元收到設備狀態請求時，發 送錯誤資訊至主機單元。第，為第4圖所示遠端資料傳輸 方法中發賴誤魏至主機單搞—實關龄意圖。如第 5圖及第3B圖所示’在較佳實施例中，第4圖中的步驟173 包含：在步驟1731巾’虛擬媒體單元發送錯誤資訊至主機單 -在步驟I732中’虛擬媒體單元發送相應於設備狀態請求 的指令成魏紅域單元。在錄倾射，齡成功應 答係使用csw來魏。在步驟m中，主機單元根據錯誤 資重新發送^料射至虛擬媒體單元。此步驟為延遲程序 的兩個步驟中的第二個。此時虛擬媒體單元不會如同步驟 120 -樣地根據資料請求要求客戶端傳輸龍至虛擬媒體單 兀’而疋繼續自客戶端接收尚未接收完成的資料(步驟⑽）。 需注意的是，在步驟171至步驟174的延遲程序執行過程中， 虛擬媒體單元可同時自客戶端接收資料(步驟160)。有別於一 般的通用序顺流主機對朝序列岐排裝置離態詢問程 序(例如通用序列匯流主機週期性地詢問通用序列匯流排裝 置是否有㈣要傳送)’延遲程序是絲避免虛擬媒體單元與 客戶端之_資料傳輸延遲造駐機單元與虛擬媒體單元之 間的通訊被重置。 右預留期間丁2未屆至，表示主機單元有可能在應答時限 Τι結束前收到虛擬媒體單元的狀態應答並作出反應，則在步 驟140中，主機單元判斷虛擬媒體單元是否已根據資料請求 元成資料的接收。在較佳實施例中，係根據自虛擬媒體單元 201214131 收到的利用CSW發送的狀態應答來判斷資料接收是否已完 f。若資料接收已完成’則在步驟1S0中’虛擬媒體單元將 資料傳輸至主機單元。第6 11為第2 _示遠·料傳輸方 法中將資料傳輸至域單元的—實關的示意目。如第6圖 及第3B圖所示，第2圖中的步驟15〇包含：在步驟151中， 虛擬媒體單元將資料傳輸至主機單元；在步驟152中，虛擬 媒體單元發送相應於資料請求的指令成功應答至主機單元。 若資料接收尚未完成，則在步驟160中，虛擬媒體單元繼續 自客戶端接收資料，並回到步驟13〇。 本發明遠端資料傳輸方法利用延遲程序的機制來避免虛 擬媒體單元與客戶端之間的資料傳輸延遲造成主機單元與虛 擬媒體單元之間的通訊被重置。 本發明已由上述相關實施例加以描述，然而上述實施例僅 為實施本發明的範例。必需指出的是，已揭露之實施例並未 限制本發明的範圍。相反地，包含於申請專利範圍之精神及 範圍之修改及均等設置均包含於本發明的範圍内。 【圖式簡單說明】 第1A圖為習知的虛擬媒體系統的示意圖； 第1B圖為第1A圖所示虛擬媒體系統傳輸資料成功，主機單 元不發生重置的示意圖； 第1C圖為第ία圖所示虛擬媒體系統的虛擬媒體單元在時限 内未收完資料造成主機單元重置發生，而使虛擬媒體系統傳 輸資料失敗的示意圖； 201214131 第ID圖為第1A圖所示虛擬媒體系統的虛擬媒體單元收完資 料，但未在時限内將資料傳給主機單元，造成主機單元重置 發生而使虛擬媒體系統傳輸資料失敗的示意圖； 第2圖為本發明遠端資料傳輸方法的一實施例的示意圖； 第3Α圖為本發明虛擬媒體系統的一實施例的示意圖； 第3Β圖為第3Α圖所示虛擬媒體系統使用第2圖所示遠端資 料傳輸方法的一實施例的示意圖； 第4圖為第2圖所示运端資料傳輸方法中的延遲程序的一實 施例的示意圖； 第5圖為第4圖所示遠端資料傳輸方法中發送錯誤資訊至主 機單元的一實施例的示意圖；以及 第6圖為第2圖所示遠端資料傳輸方法中將資料傳輸至主機 單元的一實施例的示意圖。 【主要元件符號說明】 10伺服器端 11主機單元 12虛擬媒體單元 13通用序列匯流排單元 20客戶端 3〇乙太網路201214131 VI. Description of the Invention: [Technical Field] The present invention relates to a remote data transfer method and a virtual media system using the same; in particular, the present invention relates to a method for avoiding data transmission-delay The universal sequence bus is timed out to reset the remote data transmission side, the method 'and the virtual media system using this remote data transmission method. • [Prior Art] Virtual media is a way to connect a physical or virtual client media device such as a CD player or a hard disk drive to a server-side computer, so that the server-side computer can access its own physical media. The method of the client media device. For network administrators and other people who need to manage a large number of computers, because the server-side computer can use virtual media to use soft media for software women's wear, or even use virtual media to boot, to complete the operation system% The installation of software such as the system or application, or virus scanning, etc., so the convenience is obvious. Because the Universal Serial Bus (USB) interface can provide many powerful Wei, and its convenience, the virtual media system's feeder computer uses the universal serial bus as its connection. interface. Figure 1A is a schematic diagram of a conventional virtual media system. As shown in FIG. 1A, the host unit 2 of the server terminal 1 and the virtual media unit 3 are connected by a serial/sequence bus 4, and the virtual media unit 3 and the client 5 are connected by a network 6. connection. Through the connection of the virtual media unit 3, the host unit 201214131 2:: accesses the client device by means of accessing the universal serial bus device, and then accesses the media data therein. , sound map number = the first, showing the virtual media system transmission data success s month seeking (four) "1: #财财), help the ground (4) w (C () mmand S_s Wrapper, command status packet) to send status response (If the command ^ is successful). In this example, because the command status block is successfully received within the 2-second axis response time limit, the transmission is successful. However, in the universal sequence bus protocol, the general sequence confluence master will summarize the general queue when it exceeds the response time limit after issuing a request for the universal sequence confluence and does not receive the miscellaneous response. The device is reset (then), and the data is transmitted in the network. The transmission is often caused by factors such as insufficient network bandwidth, long transmission distance or network congestion. Connections between media elements are often interrupted by network connectivity issues between the virtual media unit and the client. : Fig. 1C and Fig. 1D are diagrams showing the state of failure of two kinds of transmission data of the virtual media system shown in Fig. 1A. As shown in the lc_, the data request of the instruction 1 is regarded as a failure because the host unit does not execute the job instruction and executes the successful instruction status block packet in response to the 2 second response. As shown in the figure, although the account has given all the information to the Gu Cong unit, the command unit block is executed as the 201214131 function because the host unit does not respond to the silk age in the 2 second response time period. The data request is considered a failure. In both cases, the host unit resets the virtual media unit, so that the data transfer operation of instruction 1 must be completely re-used, which wastes time and bandwidth. What's more, in the case of poor network conditions, even resets will be repeated, so that data transfer and other operations will not be completed. SUMMARY OF THE INVENTION An object of the present invention is to provide a remote data transmission method and a virtual media system using the same, which can avoid timeout reset of a universal sequence bus caused by data transmission delay compared to the prior art. The remote data transmission method of the present invention is used between a server end and a client end, and the server end includes a host unit and a virtual media unit. The virtual media unit communicates with the domain unit in a generic order, while the domain unit has a response time limit for requests sent by the virtual media unit. The remote data transmission method includes the following steps: (a) the host unit sends a data request to the virtual media unit, 0) the virtual media unit requests the client to transmit data according to the data request; and (4) determines whether the reservation period before the end of the response time limit has been To, (6) If the reservation period has not expired until the imaginary reduction unit has received the request to complete the data reception, if the reception has been completed, the data will be transmitted to the host unit, if the reception is not completed, then, ! Receiving data from the client and returning to step (4); & read reservation period = has expired, the virtual media unit drives the host unit to execute the delay program and obtain the state of its own media, the virtual media unit simultaneously receives from the client The data 'receives the unit to send the brief request to the ship unit, and then returns to step (e). The remote data transmission method of the present invention delays the program 201214131 to avoid the (four) transmission delay between the virtual (four) body unit and the client, causing the communication between the host unit and the virtual media unit to be reset. The virtual Lai system of the present invention comprises a host unit, a Gurui flow row unit and a virtual media unit. The virtual media unit communicates with the host unit via the sequential routing unit. When the domain unit makes a request to the virtual ship unit and responds to it, the communication between the virtual unit and the virtual unit is reset. When the virtual media unit receives a new data request from the host unit, the client is required to transmit the data and receive it; before the end of the response time period, the virtual media unit is completed according to the data request. When the data is received, the data is transmitted to the host unit, otherwise the data is continuously received from the client; after the reservation period, the host unit is driven by the virtual media unit to enter the execution delay program, and the virtual media unit simultaneously receives the data from the client. The host unit then resends the data request to the virtual media unit. The virtual media system of the present invention utilizes a virtual media unit to drive the host unit into a mechanism for executing a delay program to avoid data transmission delay between the virtual media unit and the client causing communication between the host unit and the virtual media unit to be reset. [Embodiment] The present invention provides a remote data transmission method and a virtual media system using the same. In a preferred embodiment, the remote data transmission method of the present invention is used in a virtual media system or virtual media device. However, in other embodiments the remote data transmission method of the present invention can be used in other types of systems or devices. 201214131 FIG. 2 is a schematic diagram of an embodiment of a remote data transmission method according to the present invention; FIG. 3A is a schematic diagram of an embodiment of a virtual media system according to the present invention. As shown in FIG. 3A, the virtual media system includes a server terminal 10 and a client terminal 20. The server terminal 10 includes a host unit 11 and a virtual media unit 12. The remote data transmission method of FIG. 2 can be used for the host unit 11. Virtual media unit 12 and client 20. The host unit 11 and the virtual media unit 12 are connected by a universal sequence bus unit 13, that is, by a universal sequence bus protocol. The host unit 11 is a universal serial bus host (h〇st), and the virtual media unit 12 is a universal serial bus device. In this embodiment, the virtual media unit 12 and the client 20 are connected by an Ethernet 30; however, in other embodiments, they may be connected by other types of networks or other devices. . Fig. 3B is a diagram showing an embodiment of the virtual data system shown in Fig. 3A using the remote data transmission method shown in Fig. 2. As shown in Fig. 3B, the master = unit causes the CBW of the female to send the age (e.g., the data request of the instruction), and the virtual media unit transmits the status response (e.g., the execution failure of the instruction 1) using the aforementioned csw accordingly. In the universal sequence bus protocol, the universal sequence bus host has a response time limit for the request sent by the universal sequence bus device, and after the domain unit sends a request to the virtual ship unit, the response time is T1 (in this case) Guanzhong is 2 seconds) 岐 (4) When the virtual media is in the state of early response, the domain unit resets the connection with the virtual media unit. As shown in Fig. 2 and Fig. 3B, the remote data transmission method comprises the following steps: in the step m area, the domain unit sends a data plane 201214131 yuan. In the preferred embodiment, this data request is sent using CBW. In step 120, the virtual unit requests the client to transmit the data to the virtual vouchers according to the data request. In the case of the virtual media, the virtual media unit and the client are connected by the Ethernet, so the data request is sent using an Ethernet packet (for example, Tcp/ip packet). In step 130, the host unit determines whether the reservation period A before the end of the response time limit has expired. The reserved period & is a period of time less than the response time limit ' 'the length is preferably greater than the time required for the virtual media unit to send csw to the host unit plus the host unit to send the CBW to the virtual media unit, so that the host unit receives After the status of the virtual media unit is answered, there is enough time to send an instruction request to the virtual media unit as a response. If the reserved period T2 has expired, it means that the host unit cannot receive the response of the virtual media unit and responds before the end of the response time limit. In step 170, the virtual media unit drives the host unit to enter the delay program and obtain The state of the virtual media unit, the virtual media unit simultaneously receives the data from the client' and then the host unit resends the data request to the virtual media element, and then returns to step 1. Fig. 4 is a view showing a consistent example of the delay sequence in the remote data transmission method shown in Fig. 2. As shown in FIG. 4 and FIG. 3B, in the preferred embodiment, step 17 of FIG. 2 includes: in step 171, if the reservation period has expired, the virtual media unit transmits the corresponding data. The requested instruction failed to reply to the host unit. The virtual media unit drives the host unit into the delay program in a manner that sends an instruction failure response. In the preferred embodiment, the instruction failure response is sent using the CSW. In step 172, when the host unit receives the instruction failure response, it sends a device status request containing the virtual media list "yuan 201214131 return error information to the virtual media unit. This step is the first of two steps to delay the program. The real purpose of the host unit to send a device status request is not to have the virtual media unit report the device status, but rather to have the host unit wait accordingly. In a preferred embodiment, the CBW is used to send an opcode (operating code) to a command to add 3 (ie, a proxy) to request the virtual media unit to report a message containing the wrong information. Sense data. • The sensor contains a Key Code Qualifier (KCQ) error code. Table 1 is a list of values for the key qualifier error code. The key qualifier error code contains two blocks. The sense key fieid, the additional identifier code (ASC) block, and the additional identifier are defined. Odditional sense eode qualifier ' ASCQ). In a preferred embodiment, the value of the identification keystroke is 〇2h, the value of the additional identification code field is 0, and the side of the additional identification code qualifier G is Glh to indicate that the virtual unit is about to be available. The host unit can be made to wait accordingly; however, in other embodiments, the above-mentioned block can be other values listed in Table 1, other values that can be used to request the status of the device of the virtual media unit, or other conditions that can be performed by the host. The value to wait. ~ Table 1 ------ Today, _____ qualifier error code identification key __^ 卜 identification code additional identification code qualifier 02h 〇 4h -----, an Olh 02h 〇 4h --- 09h 02h 04h —-— 07h — —... 201214131 ~~~ — In V 173, although the virtual media unit receives the device status request, it sends an error message to the host unit. First, for the remote data transmission method shown in Figure 4, the error is caused by the error to the host. As shown in FIG. 5 and FIG. 3B, 'in the preferred embodiment, step 173 in FIG. 4 includes: in step 1731, the 'virtual media unit sends error information to the host list - in step I732', the virtual media unit The instruction corresponding to the device status request is sent to the Weihong domain unit. In the recording of the cast, the successful answer to the age is to use csw to Wei. In step m, the host unit resends the message to the virtual media unit based on the error. This step is the second of the two steps of the delay procedure. At this time, the virtual media unit does not request the client to transmit the dragon-to-virtual media ticket 根据 as in the case of the data request, and continues to receive the data that has not been received from the client (step (10)). It should be noted that during the execution of the delay program of steps 171 to 174, the virtual media unit can simultaneously receive data from the client (step 160). Different from the general general-purpose downstream host to the serial sequence device out-of-state inquiry program (for example, the universal sequence sink host periodically queries whether the general-purpose sequence bus device has (4) to transmit) the delay program is to avoid the virtual media unit. Communication with the client's data transfer delay between the resident unit and the virtual media unit is reset. The right reservation period is not reached, indicating that the host unit may receive a response and respond to the status of the virtual media unit before the end of the response time limit, then in step 140, the host unit determines whether the virtual media unit has been requested according to the data. The receipt of Yuancheng data. In the preferred embodiment, it is determined whether the data reception has been completed based on the status response received from the virtual media unit 201214131 using the CSW. If the data reception has been completed, then the virtual media unit transmits the data to the host unit in step 1S0. The sixth 11th is a schematic diagram of the real-time transmission of the data to the domain unit in the second method. As shown in FIG. 6 and FIG. 3B, step 15 of FIG. 2 includes: in step 151, the virtual media unit transmits the data to the host unit; in step 152, the virtual media unit transmits the corresponding data request. The instruction successfully acknowledges to the host unit. If the data reception has not been completed, then in step 160, the virtual media unit continues to receive the data from the client and returns to step 13〇. The remote data transmission method of the present invention utilizes a delay program mechanism to avoid data transmission delay between the virtual media unit and the client, causing communication between the host unit and the virtual media unit to be reset. The present invention has been described by the above related embodiments, but the above embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the invention. On the contrary, modifications and equivalents of the spirit and scope of the invention are included in the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic diagram of a conventional virtual media system; FIG. 1B is a schematic diagram of the virtual media system shown in FIG. 1A successfully transmitting data, and the host unit does not reset; FIG. 1C is the ία The figure shows that the virtual media unit of the virtual media system fails to receive the data within the time limit, causing the host unit to reset, and the virtual media system fails to transmit the data; 201214131 The ID picture is the virtual of the virtual media system shown in FIG. 1A. The media unit receives the data, but does not transmit the data to the host unit within the time limit, causing the host unit to reset and causing the virtual media system to fail to transmit data. FIG. 2 is an embodiment of the remote data transmission method of the present invention. 3 is a schematic diagram of an embodiment of a virtual media system according to the present invention; and FIG. 3 is a schematic diagram of an embodiment of a method for transmitting a remote data using the second embodiment of the virtual media system shown in FIG. 4 is a schematic diagram of an embodiment of a delay procedure in the transport data transmission method shown in FIG. 2; FIG. 5 is a remote data transmission shown in FIG. A schematic of an embodiment of the method of transmitting the error information to the host unit; and a sixth distal end of the graph shown in FIG. 2 in the data transmission method of data transmission to the host unit according to an embodiment of a schematic diagram. [Main component symbol description] 10 server terminal 11 host unit 12 virtual media unit 13 universal sequence bus unit 20 client 3〇 Ethernet