【正文】 Then MsgBox 汽包水位過(guò)低！ Else End If End IfEnd SubPrivate Sub VScroll1_Scroll() a = = End Sub細(xì)節(jié)源代碼Private Sub Command3_Click()End SubPrivate Sub Command4_Click()If = 已關(guān) Then = = 已開(kāi)Else = 已開(kāi)End IfEnd SubOption ExplicitDim a As IntegerPrivate Sub HS1_Change() a = = End SubPrivate Sub HS1_Scroll() a = = End SubPrivate Sub Command1_Click() = 已開(kāi) = End SubPrivate Sub Command2_Click() = 已關(guān) = End SubOption ExplicitDim a As IntegerPrivate Sub VS1_Change() a = = End SubPrivate Sub VS1_Scroll() a = = End Sub Modbus 通訊協(xié)議源代碼Private Sub Msm1_Onm() 39。...通訊事件發(fā)生 Dim indata As Variant Dim bte(0) As Byte Select Case Case EvReceive 39。...有接受事件發(fā)生 indata = bte(0) = AscB(indata) = bte(0) = 0 39。...清空輸入寄存器 End Select End Sub Private Sub Command18_Click() 39。...發(fā)送數(shù)據(jù) Dim Num As Integer Dim outbte(0) As Byte Num = Val() outbte(0) = CByte(Num) = 0 39。...清空輸出寄存器 = outbte(0) 39。...發(fā)送數(shù)據(jù) End Sub Private Sub Command19_Click() 39。...退出 Unload Me End Sub Private Sub Form_Load() 39。...初始化 = 1 39。...使用Com1口 = 9600,n,8,1 39。...設(shè)置通訊參數(shù) = True 39。...打開(kāi)串口 End Sub 4 單片機(jī)內(nèi)部源代碼PUSH PSW ；將程序狀態(tài)字壓入堆棧 PUSH ACC ；將累加器壓入堆棧 CLR EA ；關(guān)閉系統(tǒng)中斷CLR RI ；清除中斷標(biāo)志位 MOV A,SBUF ；從接收寄存器中讀取數(shù)據(jù) MOV 70H,A ；分解數(shù)據(jù)百、十、個(gè)位并顯示 MOV B,100DIV AB MOV 52H,A ；分解百位，送入存儲(chǔ)器52H MOV A,B MOV B,10 DIV AB MOV 51H,A ；分解十位，送入存儲(chǔ)器51H MOV 50H,B ；分解個(gè)位，送入存儲(chǔ)器50H MOV A,70H MOV B,2DIV AB 。將接受的數(shù)據(jù)除以2 MOV SBUF,A ；將得數(shù)發(fā)送到輸出寄存器 ACALL DL1 ；延時(shí)保證數(shù)據(jù)完整發(fā)送 ACALL DL1 CLR RI ；清除中斷標(biāo)志位 SETB EA ；打開(kāi)系統(tǒng)中斷 POP ACC 。累加器出棧 POP PSW ；程序狀態(tài)字出棧 RETI ；中斷程序返回 翻譯英文原文A Method For Alarming Water Level of Boiler Drum on Nuclear Power Plant Based on BP Neural NetworkYalei Quan and Xuhong YangFaculty of Automation Engineering Shanghai University of Electric Power。Shanghai 。China water level is an important parameter for boilers on both thermal power plant and nuclear power plant. It is hard to measure the level correctly. So it brings some difficulties to the control based on the drum water level, even the alarm. Usually, more than three water gauges are installed for drum water level measurement. And it adopts twooutofthree strategy for obtaining the final alarm signal in distributed control system (DCS), which is often the false alarm. Without the right alarm, it is to result in very serious disaster on power plant. One approach based on BackPropagation (BP) Neural Network is proposed in this paper for solving the problem. The measurements from different water gauges are inputted into the BP Neural Network after fuzzy process and the output of the Network represents the type of alarm. Some data of the drum water level from a nuclear power plant is applied with the method of the paper. From the experiments, it can be seen that the alarm accuracy is increased rapidly.Keywords:drum water level。DCS。 BP Neural Network。 alarm。 nuclear power plantDrum water level is an important parameter for boilers, especially for highrunning condition and highcapacity boilers, to run safely during production in thermal power plants. It is very important to monitor the drum level accurately at all times. Drum level may change frequently because of changes in load, busting conditions and water supply.Based on this control system, the dry of boiler and the failure of water screen tube can be prevented. Besides, the system must be able to unfold the purge valve—or stop the boiler if necessary ——automatically when the boiler is full so as to avoid unexpected accidents and expansion of accidents . There are several different water gages in the boiler in order to monitor the water level. Whenever the water level is out of limits, the system will give an alarm. The boiler will not be allowed to work if its boiler drum water level control system is not intact.Since 2002, there have been several accidents happened in heatengine plants in our country that were caused by inadvertent maloperations of boiler drum water level control system. These accidents have caused many serious economic losses. Besides, It was reported that about 25% of emergency shutdowns in the nuclear power plants based on pressurizedwater reactor (PWR) are caused by poor control of the steam generator (SG) water level[1].We can expect that more and more problems that would be caused by insufficient accuracy of water level monitoring system or inplete actions of water level control system during the initiate of boiler will happen with the growing of thermal power generating units. Giving an overview of those major accidents happened in these years, we can find that the inaccuracy of measuring system and inappropriate signal processing are the main reasons.The traditional twooutofthree method for boiler drum water level control can be achieved by DCS modules, with a probability that the two signals selected are far from the true water level while the third one is much closer. Thus, a misjudgment is possible to happen. To improve, lately a Multimodel predictive control method[2], as well as a Fuzzy Logic method[3], has been used for nuclear steam generator. This method is useful but it st