變數就像是在NXT記憶體中一個存放數值的地方.其他指令利用資料線就可以讀取或是改變變數當時數值.
Think of a variable as a place to store a value in the NXT’s built-in memory. Other programming blocks can read the variable’s current value (and even change it) by connecting to the block with data wires.
注意:如果要改變資料型態或是變數名稱時,則必須使用編輯選單的"定義變數"功能來設定.
Note: if you need to change the data type or name of your variable, go back to the Define Variable command of the Edit menu and change the setting there.
變數值可隨時間改變.假設一個變數名稱叫做"紀錄的光量"並給予初始值"50",接著當機器人(配有光源感應器)行進到一地點時,可使用"寫入"功能的變數指令來紀錄當時的光量.光源感應器的輸出資料線必須連到變數指令的輸入埠上.
A variable’s value can change over time. You might create a variable called “Recorded Light Level” and give it an initial value of 50. Then as your robot (fitted with a light sensor) drives to a certain location, you can use a Variable block (set to “write”) to record the current light level at the location. To do this, you would connect an output data wire from the Light Sensor block to the input plug of the Variable block.
接著,在程式中就可以使用"讀取"功能的變數指令來讀取所紀錄的光量.而其他指令即可用資料線從變數指令的輸出埠來存取變數值(也就是"紀錄的光量")
Later in your program you can use a Variable block (set to “read”) to read the light value recorded at the location. Other blocks connected to the block’s output plug by data wire would be able to access the information saved in the variable (i.e., the recorded light level).
注意:如果要改變資料型態或是變數名稱時,則必須使用編輯選單的"定義變數"功能來設定.
Note: if you need to change the data type or name of your variable, go back to the Define Variable command of the Edit menu and change the setting there.
若要讓主程式與我的指令(也就是兩個 .rbt檔案)共享資料,需按照下列步驟:
In order to share data between your main program and a My Block (i.e., between two .rbt files), do these two things:
無論在哪裡使用該變數都會讀取/寫入NXT同位置的記憶體.
Any place that the variable is used will read/write to the same memory location on the NXT.
用資料線可以任意地用來控制變數指令.(從其他指令的資料集線器到變數指令的資料集線器).
You can control the Variable block dynamically by connecting data wires (from other blocks’ data hubs) to the Variable block’s data hub.
把指令放在工作區上後,可以按圖示的左下角來打開資料集線器.
Open a block’s data hub by clicking the tab at the lower left edge of the block after it has been placed on the work area.
連接到集線器左邊連接埠的資料線是屬於負責傳遞資料進入指令中,而要從指令送出資料時,則須從集線器的右邊連接埠連接資料線.
Data wires carrying input information to a block are connected to the plugs on the left side of its data hub. Data wires carrying output information are connected to the plugs on the right side.
[A]輸入連接埠 [A] Input plug
[B]輸出連結部 [B] Output plug
[C]數字資料線(黃) [C] Number data wire (yellow)
[D]邏輯資料線(綠) [D]Logic data wire (green)
[E]文字資料線(橘) [E]Text data wire (orange)
[F]無效資料線(灰) [F]Broken data wire (gray)
如果輸入連接埠有對應的輸出連接埠(請參閱 A 以上)時,那麼輸入的資料就會原封不動地傳遞到輸出連接埠.在這樣的情況下, 如果輸入連接埠連著資料線,那麼就只能使用輸出連結埠來做連結. 也就是說,當連結輸出連接線到這樣的輸出連接埠,而不透過相對應的輸入資料線時,就會讓該輸出連接線呈現無效的狀態.
If an input plug has a corresponding output plug (see A above), the input data will pass through from the input plug to the output plug without being changed. In this case, you can only use the output plug if the input plug is connected to an input data wire; connecting an output data wire to such an output plug without a connected input data wire will cause the output data wire to be “broken” (and colored gray).
每條資料線都負責傳送特定資料.例如,一條從邏輯連接埠拉出的資料線則只能連結到另一個同屬邏輯連接埠的集線器上.
Each data wire carries a specific type of data between blocks. For example, if a data wire is dragged from a logic plug on a block’s data hub, it can only be connected to a logic plug on another block’s data hub. The chart below shows what kind of data each plug can accept or send out.
資料線依照特定的顏色作識別:黃色資料線傳送數值資料、綠色資料線傳送邏輯資料(真/偽)及橘色資料線傳送文字資料
Data wires are identified with specific colors: wires carrying number data are colored yellow, wires carrying logic data are colored green, and wires carrying text data are colored orange.
如果資料線連結到錯誤資料型態的連接埠時,則該資料線會呈現斷線無效狀態並以灰色表示.而有無效的資料線存在就無法下載程式.
If you try to connect a data wire to a plug of the wrong data type, the data wire will be broken (and colored gray). You will not be able to download your program if a data wire is broken.
點選無效的資料線時,在工作區右下方的幫助視窗中會看到無效的原因.
If you click a broken wire you can read why it is broken in the small help window in the lower right corner of the work area.
如果資料線傳輸該連接埠資料範圍之外的資料時,該指令不是忽略資料就是轉成合理範圍內的資料.對那些只能接收少量輸入值的連接埠來說(例如,0,1,或2),該連結埠就會忽略超出範圍的數值.
If an input data wire transmits a value outside the possible range of the plug it is connected to, the block will either ignore the value or change it to a value within its range. For plugs that allow just a few input values (example: just 0, 1, or 2), the plug will ignore the input if a value arrives outside its range.
>而對那些可以接收大量範圍輸入值(例如: 0~100)的連接埠來說,該連接埠就會將數值轉成可接受的範圍. 例如, 移動指令的動力連接埠接收到150的輸入值時,那麼移動指令就會轉成100(也就是動力連接埠的範圍內).
For plugs that accept larger input ranges (example: 0 – 100), the plug will force any input outside its range to fit. For example, if a Move block’s Power plug receives an input value of 150, the block will change the input value to 100 (i.e., a number within the Power plug’s range).
連結埠 Plug |
資料型態 Date Type |
資料範圍 Possible Range |
資料意義 What the Values Mean |
連接埠例外說明 This Plug is Ignored When... |
|
數值* Value* |
任意 Any |
讀取或寫入的數值 Value to read or write |
*此資料連接埠會隨著變數的資料型態而改變外觀.
*This data plug will change appearance based on the variable's data type.