Getting and Moving Data / 获取和移动数据
顺便访问的英文短语，Let&34;advanced&39;ll see some marked differences between many of the manufacturers functionality and implementation. On the lines that follow we'll explore two of the most popular ways to get and manipulate data.
现在让我们开始处理一些数据。这可以被认为是进入PLC的“高级”功能。这也是我们将看到许多不同品牌PLC之间的功能和执行的一些显著差异的地方。接下来，我们将探讨获取和操作这些数据的两种最流行的方法。
Why do we want to get or acquire data? The answer is simple. Let&39;s an A/D module. This module acquires Analog signals from the outside world (a varying voltage or current) and converts the signal to something the plc can understand (a digital signal i.e. 1&39;s). Manufacturers automatically store this data into memory locations for us. However，we have to get the data out of there and move it some place else otherwise the next analog sample will replace the one we just took. In other words，move it or lose it! Something else we might want to do is store a constant (i.e. fancy word for a number)，get some binary data off the input terminals ( maybe a thumbwheel switch is connected there，for example)，do some math and store the result in a different location，etc...
我们为什么要获取或者采集数据呢？答案很简单。假设我们正在使用某个品牌PLC的可选模块，也许是A/D模块（模/数转换模块），这个模块从外部世界采集模拟信号（一个变化的电压或电流），并将信号转换成PLC可以理解的东西（一个数字信号，即1和0），PLC自动将这些数据存储到内存位置，然而，我们必须取出这个数据，并把它移动到其他地方，否则下一个采集到的模拟信号将取代我们上一个收到的那个模拟信号。换句话说，要么移动它，要么失去它！我们可能想做的另一件事是存储一个常量（即一个数字的别称），从输入终端获取一些二进制数据（例如，可能在输入端连接了一个拨码开关），然后做一些计算并将结果存储在不同的位置，等等……
As was stated before there are typically 2 common instruction &34; to accomplish this. Some manufacturers use a single instruction to do the entire operation while others use two separate instructions. The two are used together to accomplish the final result. Let's now look briefly at each instruction.
The single instruction is commonly called MOV (move). Some vendors also include a MOVN (move not). It has the same function of MOV but it transfers the data in inverted form. (i.e. if the bit was a 1，a 0 is stored/moved or if the bit was a 0，a 1 is stored/moved). The MOV typically looks like that shown below.
英语中“顺便”怎麼说 你好！ 顺便 by the way 英[bai ðə wei] 美[baɪ ði we] [词典] 顺便地，附带说说; 顺便一提; [例句]By the way, how did your seminar go? 对了。
单个指令通常称为MOV（move），有些品牌的PLC还包括一个MOVN（move not）指令，它具有与MOV相同的功能，但它以相反的形式传输数据（例如，如果位是1，则0被存储or移动；如果位是0，则1被存储or移动）。MOV指令的符号通常如下图所示。
MOV instruction symbol
The paired instruction typically is called LDA (LoaD Accumulator) and STA (STore Accumulator). The accumulator is simply a register inside the CPU where the plc stores data temporarily while its working. The LDA instruction typically looks like that shown below，while the STA instruction looks like that shown below to the right.
成对的指令通常称为LDA（LoaD Accumulator）和STA（Store Accumulator）。累加器（Accumulator）只是CPU内部的一个寄存器，PLC在工作时将数据临时储存在这种寄存器里。LDA指令通常如下左图所示，而STA指令则如下右图所示。
Regardless of whether we use the one symbol or two symbol instruction set (we have no choice as it depends on whose plc we use) they work the same way.
conveniently 这两个单词,但只做为单词,它们的用法与我们中文所说的顺便意思又不太一样.你要说这句话就只是"帮我把杯子拿过来"不加后面的"顺便"但如果你一定要用到"顺便"那你还得再加一些内容.给你几个例子,你就明白。
无论我们使用单个符号指令集还是成对符号指令集（我们没有选择，因为这取决于我们使用哪个品牌的PLC），它们的工作方式是都相同的。
Let's see the single instruction first. The MOV instruction needs to know 2 things from us.
顺便 英文一般用by the way 我一会去吃饭，顺便买张电话卡 这句用on the way 较好 I will go to the restaurant a while later and I will buy a phone card on the way。.
让我们先看看单个指令，MOV指令需要从我们这里知道两件事：（参看上面MOV单指令符号）
Source (xxxx) - This is where the data we want to move is located. We could write a constant here (2222 for example). This would mean our source data is the number 2222. We could also write a location or address of where the data we want to move is located. If we wrote DM100 this would move the data that is located in data memory 100.
源地址（xxxx） - 这是我们要移动的数据所在的位置，我们可以在这里写一个常数（比如2222），这意味着我们的源数据是2222，我们还可以写入要移动的数据所在的位置或地址，比如我们写入DM100，这意思是我们将移动位于内存DM100中的数据。
Destination (yyyy) - This is the location where the data will be moved to. We write an address here. For example if we write DM201 here the data would be moved into data memory 201. We could also write 0500 here. This would mean that the data would be moved to the physical outputs. 0500 would have the least significant bit，0501 would have the next bit... 0515 would have the most significant bit. This would be useful if we had a binary display connected to the outputs and we wanted to display the value inside a counter for the machine operator at all times (for example).
目标地址 (yyyy) - 这是数据将要被移动到的位置。我们在这里写一个地址，例如，如果我们在这里写入DM201，那么数据将被移动到内存DM201中；这里也可以写0500，这意味着数据将被移动到物理输出0500这个点。0500会有最低有效位，0501会有下一个位......0515将会有最高有效位。如果我们在输出端连接有显示，并且我们希望为机器操作者始终显示计数器里的值（这是打个比方），那么这个指令将非常有用。
The ladder diagram to do this would look similar to that shown below.
完成此任务的梯形图与下图类似。
Notice that we are also using a &34; instruction here. The reason is simply because if we didn&39;s not (for example an external display would be unreadable because the data changes too much).
注意，这里我们还使用了“DIFU”（上升沿）指令。原因很简单，因为如果我们不这样做，数据将在每次扫描期间都会移动。有时这是件好事（例如，如果我们要从A/D模块不间断获取数据）；但有时不是（例如，因为数据变化太快，外部显示将无法辨识）。
The ladder shows that each time real world input 0000 becomes true，difu will become true for only one scan. At this time LoaD 1000 will be true and the plc will move the data from data memory 200 and put it into data memory 201.
Simple but effective. If，instead of DM200，we had written 2222 in the symbol we would have moved (written) the number (constant) 2222 into DM201.
从梯形图中可以看出，每当现实世界的输入0000变为“真”（True）时，DIFU指令只会在一个扫描周期里变为“真”（True）。此时LD1000为“真”（True），PLC将把数据从DM200中移动到DM201中。
The two symbol instruction works in the same method but looks different. To use them we must also supply two things，one for each instruction:
现在让我们看看双符号指令，它们工作在相同的方法，但看起来却又不同。要用这种指令，我们也必须明白两样东西，一个一个说明吧：（参看上面成对指令LDA和STA指令符号）
LDA - this instruction is similar to the source of a MOV instruction. This is where the data we want to move is located. We could write a constant here (2222 for example). This would mean our source data is the number 2222. We could also write a location or address of where the data we want to move is located. If we wrote DM100 this would move the data that is located in data memory 100.
LDA - 这个指令类似于MOV指令的源地址，这就是我们要移动的数据所在的位置，我们可以在这里写一个常数（比如2222），这意味着我们的源数据是2222。我们还可以写入要移动的数据所在的位置或地址。比如我们写入DM100，这意思是将移动位于内存DM100中的数据。
STA - this instruction is similar to the destination of a MOV instruction. We write an address here. For example if we write DM201 here the data would be moved into data memory 201. We could also write 0500 here. This would mean that the data would be moved to the physical outputs. 0500 would have the least significant bit，0501 would have the next bit... 0515 would have the most significant bit. This would be useful if we had a binary display connected to the outputs and we wanted to display the value inside a counter for the machine operator at all times (for example).
STA - 这条指令类似于MOV指令的目标地址，我们在这里写一个地址，比如，如果我们在这里写入DM201，那么数据将被移动到内存DM201中；这里也可以写0500，这意味着数据将被移动到物理输出点0500，0500会有最低有效位，0501会有下一个位......0515将会有最高有效位。如果我们在输出端连接有显示，并且我们希望为机器操作者始终显示计数器里的值（这是打个比方），那么这个指令将非常有用。
The ladder diagram to do this would look similar to that shown above. Here again we notice that we are using a one-shot so that the move only occurs once for each time input 0000 becomes true. In this ladder we are moving the constant 2222 into data memory 200. The &" is used by some manufactures to symbolize a decimal number. If we just used 2222 this plc would think it meant address 2222. PLCs are all the same... but they are all different.
完成此任务的梯形图与上面所示梯形图类似。这里我们再次注意到，我们使用的是One-Shot指令（DIFU上升沿），因此每次输入0000变为“真”（True）时，数据移动只发生一次。在这个梯形图中，我们将常数2222移到内存DM200中。梯形图中222前面的“”，这个PLC可能会认为它的意思是地址2222。PLC都是这样的......但它们又都是不同的。
In the example above，data memory 200 (DM200) initially holds the constant (number) 0000. Each time the operator pushes button 0000 the difu instruction will turn on (become true) FOR ONE SCAN. When this happens we load the constant(number) 2222 and move it into data memory 200(DM200). Not a very useful application by itself but it should show what the instruction pair does. In later chapters you'll see that this is an invaluable instruction.
在上面的示例中，数据内存200(DM200)最初保存常量0000（上图中那个红色数字），每次操作员按下0000按钮时，DIFU指令就会变为“真”（True）并保持一个扫描周期，这时，我们加载常量（number）2222并将其移动到数据内存200(DM200)中。上面这个梯形图不是一个非常有用的应用程序，它只是为了显示这对双指令的功能。在后面的章节中，您将看到这是一条无价的指令。
我们可以把这个指令看作是通向高级指令的大门。我相信你会发现它的用处和价值，我们将在未来看到，许多高级功能没有这个指令是不可能的！
drop into 1, (疲倦地)往…一倒，疲倦地倒在…上：He dropped into an armchair,utterly worn out.他倒在扶手椅子里，已精疲力竭了。2, [口语]顺便走访；顺便(或偶然)进入；去一会儿，停一会儿：He dropped into a。
