三菱PLC模拟量PID
用三菱PLC-FX2N与F940的PID控制恒压供水
一．控制的要求：〔1〕有两台水泵，按设计要求一台运行，一台备用，自动运行时泵运行累计100H轮换一次，手动时不切换；〔2〕两台水泵分别由M1、M2电动机拖动，电动机同步转速为3000转/min，由KM1、KM2控制；〔3〕切换后起动和停电后起动须5s报警，运行异常可自动切换到备用泵，并报警；〔4〕采用PLC的PID调节指令〔5〕变频器〔使用三菱FR-A540〕采用PLC的特殊功能单元FX0N-3A的模拟输出，调节电动机的转速；〔6〕水压在0～10kg可调，通过触摸屏〔使用三菱F940〕输入调节；〔7〕触摸屏可以显示设定水压、实际水压、水泵的运行时间、转速、报警信号等；〔8〕变频器的其余参数自行设定。
二.软件的设计：1．I/O分配〔1〕触摸屏输入，M500：自动起动；M100：手动1号泵；M101：手动2号泵；M102：停顿；M103：运行时间复位；M104：去除报警；D300：水压设定。
〔2〕触摸屏输出，Y0：1号泵运行指示；Y1：2号泵运行指示，T20：1号泵故障；T21：2号泵故障；D101：当前水压；D502：泵累计运行的时间；D102：电动机的转速。
〔3〕PLC输入，X1：1号泵水流开关；X2：2号泵水流开关；X3：过压保护。
〔4〕PLC输出，Y1：KM1；Y2：KM2；Y4：报警器；10：变频器STF。
2．触摸屏画面设：根据控制要求及I/O分配，按下列图1-1制作触摸屏画面。
〔三菱F940触摸屏的画面制作图1-1〕3．PLC的程序：(1).根据控制要求，PLC程序如下列图2-1，3-1所示。
〔PLCFX2N-48MR的程序梯形图图2-1〕〔PLCFX2N-48MR的程序梯形图图3-1〕(2).PLC的关键性程序构造简述:PLC得电后,通过程序把模块中的摸拟量压力信号转化成压力数字量(D160),将压力的数据存放器D160的值除以25以校正压力的实际值(由特殊功能模拟模块FX0N-3A的资料可知:因0—10kg对应的是数值是0—250,所以压力与数值的关系是1:25)。
模块七_PLC模拟量及PID控制
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任务一： 任务一： PLC模拟量控制及应用 模拟量控制及应用
任务一： 任务一： PLC模拟量控制及应用 模拟量控制及应用
4．模拟量输入/输出举例 ．模拟量输入 输出举例
例2 从 模拟 量 输出 通 道AQWO 输出10V 电压， EM232的输出电压范围是-10V～10V，其数据范 围 为 -32000 ～ 32000 ， 相 应 的 数 据 值 -2000 ～ 2000。
1．模拟量输入 ．
（2）模拟量输入的配置
电流发送器 电压发送器 未用端子
开 关
固定端子块
配置开关 增益
增益
DIP设定开关
没有使用 24VDC电源和公共端
图7-1 EM231模拟量输入模块端子及DIP开关示意图
任务一： 任务一： PLC模拟量控制及应用 模拟量控制及应用
1．模拟量输入 ．
（2）模拟量输入的配置
电流发送器 电压发送器 未用端子
开 关
固定端子块
配置开关 增益
增益
DIP设定开关
没有使用 24VDC电源和公共端
图7-1 EM231模拟量输入模块端子及DIP开关示意图
任务一： 任务一： PLC模拟量控制及应用 模拟量控制及应用
1．模拟量输入 ．
（2）模拟量输入的配置
电流变送器 电压变送器 空闲端子
3PLC程序的PID参数的设定与调节(精)
PID参数的设置与调节PID控制简介目前工业自动化水平已成为衡量各行各业现代化水平的一个重要标志。
同时，控制理论的发展也经历了古典控制理论、现代控制理论和智能控制理论三个阶段。
智能控制的典型实例是模糊全自动洗衣机等。
自动控制系统可分为开环控制系统和闭环控制系统。
一个控控制系统包括控制器﹑传感器﹑变送器﹑执行机构﹑输入输出接口。
控制器的输出经过输出接口﹑执行机构﹐加到被控系统上﹔控制系统的被控量﹐经过传感器﹐变送器﹐通过输入接口送到控制器。
不同的控制系统﹐其传感器﹑变送器﹑执行机构是不一样的。
比如压力控制系统要采用压力传感器。
电加热控制系统的传感器是温度传感器。
目前，PID控制及其控制器或智能PID控制器（仪表）已经很多，产品已在工程实际中得到了广泛的应用，有各种各样的PID控制器产品，各大公司均开发了具有PID参数自整定功能的智能调节器(intellig ent regulator)，其中PID控制器参数的自动调整是通过智能化调整或自校正、自适应算法来实现。
有利用PID控制实现的压力、温度、流量、液位控制器，能实现PID控制功能的可编程控制器(PLC)，还有可实现PID控制的PC系统等等。
可编程控制器(PLC)是利用其闭环控制模块来实现PID控制，而可编程控制器(PLC)可以直接与Cont rolNet相连，如Rockwell的PLC-5等。
还有可以实现PID控制功能的控制器，如Rockwell的Logix产品系列，它可以直接与Contro lNet相连，利用网络来实现其远程控制功能。
1、开环控制系统开环控制系统(open-loop control system)是指被控对象的输出(被控制量)对控制器(controller)的输出没有影响。
在这种控制系统中，不依赖将被控量反送回来以形成任何闭环回路。
2、闭环控制系统闭环控制系统(closed-loop control system)的特点是系统被控对象的输出(被控制量)会反送回来影响控制器的输出，形成一个或多个闭环。
三菱PLC(温度PID)实验
三菱PLC(温度PID)实验指导书主讲:雷老师湖北祥辉电气自动化培训中心温度PID控制实验一、实验目的熟悉使用三菱FX系列的PID控制，通过对实例的模拟，熟练地掌握PLC控制的流程和程序调试。
二、实验设备1.THPLC-D型（挂箱式）实验装置一台2.FM-26温度控制挂箱一个（包含Pt100热电偶一个）3.计算机一台(或与FX0N系列PLC相配套的手持编程器一个)4.PC/PLC编程数据线一根5.实验导线若干三、接线“Pt100输入”接电热偶（注意补偿端的连线）；“加热指示”和“冷却风扇”接PLC 主机24V电源；“控制输入”接模拟量模块（FXon-3A）的IOUT和COM；“信号输出”接模拟量模块（FXon-3A）的VIN1和COM1。
四、实验原理(1)本实验说明本实验为温度PID控制的演示实验。
其中，系统中的Pt100为热电偶,用来监测受热体的温度，并将采集到的温度信号送入变送器，再由变送器输出单极性模拟电压信号，到模拟量模块，经内部运算处理后，输出模拟量电流信号到调压模块输入端，调压模块根据输入电流的大小，改变输出电压的大小，并送至加热器。
欲使受热体维持一定的温度，则需一风扇不断给其降温。
这就需要同时有一加热器以不同加热量给受热体加热，这样才能保证受热体温度恒定。
本系统的给定值（目标值）是受热体温度为50℃时的值，可以预先设定后直接输入到回路中；过程变量由在受热体中的Pt100测量并经温度变送器给出，为单极性电压模拟量；输出值是送至加热器的电压，其允许变化范围为最大值的0%至100%。
(2)理解FXon系列的PID功能指令FXon系列的PID回路运算指令的功能指令编号为FNC88,源操作数[S1],[S2],[S3]和目标操作数均为D，16位运算占9个程序步，[S1],[S2]分别用来存放给定值SV和当前测量到的反馈值PV,[S3]--[S3]+6用来存放控制参数的值,运算结果MV存放在[D]中。
三菱PLC自学资料PID若何设置参数[整理版]
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可编程控制器概况可编程控制器（PROGRAMMABLE CONTROLLER，简称PC）。
与个人计算机的PC相区别，用PLC表示。
PLC是在传统的顺序控制器的基础上引入了微电子技术、计算机技术、自动控制技术和通讯技术而形成的一代新型工业控制装置，目的是用来取代继电器、执行逻辑、记时、计数等顺序控制功能，建立柔性的程控系统。
国际电工委员会（IEC）颁布了对PLC的规定：可编程控制器是一种数字运算操作的电子系统，专为在工业环境下应用而设计。
它采用可编程序的存贮器，用来在其内部存贮执行逻辑运算、顺序控制、定时、计数和算术运算等操作的指令，并通过数字的、模拟的输入和输出，控制各种类型的机械或生产过程。
可编程序控制器及其有关设备，都应按易于与工业控制系统形成一个整体，易于扩充其功能的原则设计。
PLC具有通用性强、使用方便、适应面广、可靠性高、抗干扰能力强、编程简单等特点。
可以预料：在工业控制领域中，PLC控制技术的应用必将形成世界潮流PLC程序既有生产厂家的系统程序，又有用户自己开发的应用程序，系统程序提供运行平台，同时，还为PLC程序可靠运行及信息与信息转换进行必要的公共处理。
用户程序由用户按控制要求设计。
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第二章PLC的结构及基本配置一般讲，PLC分为箱体式和模块式两种。
但它们的组成是相同的，对箱体式PLC，有一块CPU板、I/O板、显示面板、内存块、电源等，当然按CPU性能分成若干型号，并按I/O点数又有若干规格。
对模块式PLC，有CPU模块、I/O模块、内存、电源模块、底板或机架。
无任哪种结构类型的PLC，都属于总线式开放型结构，其I/O能力可按用户需要进行扩展与组合。
PLC的基本结构框图如下：一、CPU的构成PLC中的CPU是PLC的核心，起神经中枢的作用，每台PLC至少有一个CPU，它按PLC的系统程序赋予的功能接收并存贮用户程序和数据，用扫描的方式采集由现场输入装置送来的状态或数据，并存入规定的寄存器中，同时，诊断电源和PLC内部电路的工作状态和编程过程中的语法错误等。
三菱PID讲解
超出
［S3］+ 24 无效
Bit2: 输出变化量（增方） 超出
Bit3: 输出变化量（减方） 超出
PID 指令可以同时多次使用，但是用于运算的[S3]、[D]的数据寄存器元件号 不能重复。
PID 指令可以在定时中断、子程序、步进指令和转移指令内使用，但是应将 ［S3］＋7 清零（采用脉冲执行的 MOV 指令）之后才能使用。
以上公式中：△MV 是本次和上一次采样时 PID 输出量的差值，MVn 是本次的 PID 输出量；EVn 和 EVn-1 分别是本次和上一次采样时的误差，SV 为设定值；PVn 是本次采样的反馈值，PVnf、PVnf-1 和 PVnf-2 分别是本次、前一次和前两次滤 波后的反馈值，L 是惯性数字滤波的系数；Dn 和 Dn-l 分别是本次和上一次采样 时的微分部分；K p 是比例增益，T S 是采样周期，T I 和 T D 分别是积分时间 和微分时间，αD 是不完全微分的滤波时间常数与微分时间 TD 的比值。
在工业控制中，PID 控制（比例-积分-微分控制）得到了广泛的应用，这是 因为 PID 控制具有以下优点：
1）不需要知道被控对象的数学模型。实际上大多数工业对象准确的数学模 型是无法获得的，对于这一类系统，使用 PID 控制可以得到比较满意的效果。据 日本统计，目前 PID 及变型 PID 约占总控制回路数的 90%左右。
积分作用与当前误差的大小和误差的历史情况都有关系，只要误差不为零， 控制器的输出就会因积分作用而不断变化，一直要到误差消失，系统处于稳定状 态时，积分部分才不再变化。因此，积分部分可以消除稳态误差，提高控制精度， 但是积分作用的动作缓慢，可能给系统的动态稳定性带来不良影响。积分时间常 数 T I 增大时，积分作用减弱，系统的动态性能（稳定性）可能有所改善，但是 消除稳态误差的速度减慢。
三菱PLCPID调节手册
Programming ManualMitsubishi Programmable Logic ControllerQCPU(Q Mode)/QnACPU(PID Control Instructions)• SAFETY CAUTIONS •(You must read these cautions before using the product)In connection with the use of this product, in addition to carefully reading both this manual and the related manuals indicated in this manual, it is also essential to pay due attention to safety and handle the product correctly.The safety cautions given here apply to this product in isolation. For information on the safety of the PC system as a whole, refer to the CPU module User's Manual.Store this manual carefully in a place where it is accessible for reference whenever necessary, and forward a copy of the manual to the end user.REVISIONS* The manual number is given on the bottom left of the back cover.Print Date* Manual Number RevisionDec., 1999SH (NA) 080040-A First editionJun., 2001SH (NA) 080040-B Partial additionAbout Manuals, Chapter 1, Chapter 2, Section 2.1, 3.1, 3.2, 3.3, 3.3.1,4.2.3, 4.3.2, 4.3.5, Chapter 5, Section5.1, 5.2, Chapter 6, Chapter 7,Section 8.1, 8.2Japanese Manual Version SH-080022-BThis manual confers no industrial property rights or any rights of any other kind, nor does it confer any patent licenses. Mitsubishi Electric Corporation cannot be held responsible for any problems involving industrial property rights whichmay occur as a result of using the contents noted in this manual.1999 MITSUBISHI ELECTRIC CORPORATIONINTRODUCTIONThank you for choosing the Mitsubishi MELSEC-Q/QnA Series of General Purpose Programmable Controllers. Please read this manual carefully so that the equipment is used to its optimum. A copy of this manual should be forwarded to the end User.CONTENTS1. GENERAL DESCRIPTION 1 – 1 to 1 - 21.1 PID Processing Method...........................................................................................................................1 - 22. SYSTEM CONFIGURATION FOR PID CONTROL 2 - 1 to 2 - 22.1 Applicable PLC CPU................................................................................................................................2 - 13. PID CONTROL SPECIFICATIONS 3 - 1 to 3 - 63.1 Performance Specifications.....................................................................................................................3 - 1 3.2 Operation Expressions.............................................................................................................................3 - 1 3.3 PID Control Instruction List......................................................................................................................3 - 23.3.1 How to read the instruction list..........................................................................................................3 - 33.3.2 PID operation instruction list.............................................................................................................3 - 54. PID CONTROL 4 - 1 to 4 - 124.1 Outline of PID Control..............................................................................................................................4 - 1 4.2 PID Control...............................................................................................................................................4 - 24.2.1 Operation method..............................................................................................................................4 - 24.2.2 Normal operation and reverse operation..........................................................................................4 - 24.2.3 Proportionate operation (P operation)..............................................................................................4 - 44.2.4 Integrating operation (I operation)....................................................................................................4 - 54.2.5 Differentiating operation (D operation).............................................................................................4 - 64.2.6 PID operation.....................................................................................................................................4 - 7 4.3 PID Control Functions..............................................................................................................................4 - 74.3.1 Bumpless changeover function.........................................................................................................4 - 74.3.2 MV higher/lower limit control function...............................................................................................4 - 84.3.3 Monitorning PID control with the AD57(S1) (QnACPU only)...........................................................4 - 94.3.4 Function for transfer to the SV storage device for the PV in manual mode..................................4 - 104.3.5 Changing PID Control Data or input/output Data Setting Range(High Performance model QCPU Only).........................................................................................4 - 11 5. PID CONTROL PROCEDURE 5 - 1 to 5 - 105.1 PID Control Data......................................................................................................................................5 - 35.1.1 Number of loops to be used and the number of loops to be executed in a single scan.................5 - 65.1.2 Sampling cycle..................................................................................................................................5 - 7 5.2 Input/Output Data.....................................................................................................................................5 - 86. PID CONTROL INSTRUCTIONS 6 - 1 to 6 - 27. HOW TO READ EXPLANATIONS FOR INSTRUCTIONS7 - 1 to 7 - 28. PID CONTROL INSTRUCTIONS8 - 1 to 8 - 108.1 PID Control Data Settings.........................................PIDINIT,PIDINITP................................................8 - 2 8.2 PID Control ...............................................................PIDCONT,PIDCONTP.........................................8 - 3 8.3 Monitoring PID Control Status (QnACPU only).......PID57,PID57P......................................................8 - 5 8.4 Operation Stop/Start of Designated Loop No..........PIDSTOP,PIDSTOPP,PIDRUN,PIDRUNP.........8 - 8 8.5 Parameter Change at Designated Loop...................PIDPRMW,PIDPRMWP......................................8 - 99. PID CONTROL PROGRAM EXAMPLES9 - 1 to 9 - 109.1 System Configuration for Program Examples.........................................................................................9 - 1 9.2 Program Example for Automatic Mode PID Control...............................................................................9 - 2 9.3 Program Example for Changing the PID Control Mode between Automatic and Manual....................9 - 6APPENDIX APP - 1APPENDIX 1 PROCESSING TIME LIST................................................................................................APP – 1About ManualsThe following manuals are also related to this product.In necessary, order them by quoting the details in the tables below. Related ManualsManual Name Manual Number (Model Code)High Performance model QCPU (Q mode) User's Manual(Function Explanation/Program Fundamentals)Describes the functions, programming procedures, devices, parameter types and program types necessary in program creation using QCPU (Q mode).(Option)SH-080038 (13JL98)QnACPU Programming Manual (Fundamentals)Describes how to create programs, the names of devices, parameters, and types of program.(Option)IB-66614 (13JF46)QCPU (Q mode) /QnACPU Programming Manual (Common Instructions)Describes how to use sequence instructions, basic instructions, and application instructions.(Option)SH-080039 (13JF58)QnACPU Programming Manual (Special Function)Describes the dedicated instructions for special function modules available when using theQ2ACPU(S1), Q3ACPU, and Q4ACPU.(Option)SH-4013 (13JF56)QnACPU Programming Manual (AD57 Instructions)Describes the dedicated instructions for controlling an AD57(S1) type CRT controller module available when using the Q2ACPU(S1), Q3ACPU, or Q4ACPU.(Option)IB-66617 (13JF49)QCPU (Q mode) / QnACPU Programming Manual (SFC)Describes the system components, performance specifications, and functions, protramming, debugging and error codes of MELSAP-3(Option)SH-080041 (13JF60)Q4ARCPU Programming Manual (Application PID Edition)Describes the programming procedures and device name necessary in program creation to control Applied PID using process control instructions.(Option)IB-66695 (13JF52)Before reading this manual, refer to High Performance model QCPU (Q mode) User'sManual (Function Explanation/Programming Fundamentals) and QnACPUProgramming Manual (Fundamentals) in order to confirm the programs, I/Oprocessing, and devices used with High Performance model QCPU(Q mode)/QnACPU.Describes the instructionsused for Applied PIDcontrol.Generic Names:High Performance model QCPU...Generic names for Q02CPU, Q02HCPU, Q06HCPU, Q12HCPU, Q25HCPU QnACPU ........................................Generic names for Q2ASCPU, Q2ASCPU-S1, Q2ASHCPU, Q2ASHCPU-S1, Q2ACPU, Q3ACPU, Q4ACPU, Q4ARCPUCPU module....................................Generic names for QnACPU, High Performance model QCPU1. GENERAL DESCRIPTION1 This manual describes the sequence program instructions used to execute PID controlwith the High Performance model QCPU/QnACPU.The High Performance model QCPU /QnACPU has the capability to use instructionsfor PID control as a standard feature, so PID control can be executed by loading anA/D conversion module and a D/A conversion module.In addition, the PID control status can be monitored with an AD57(S1).POINTThe Basic model QCPUs (Q00JCPU, Q00CPU, Q01CPU) are not compatible withthe PID control instructions.Use the High Performance model QCPU to use the PID control instructions.REMARKThe High Performance model QCPU is the generic term of the Q02CPU, Q02HCPU,Q06HCPU, Q12HCPU and Q25HCPU.Any of them is abbreviated to the High Performance model QCPU in this manual.1.1 PID Processing MethodThis section describes the processing method for PID control using PID controlinstructions. (For details on PID operations, see Chapter 4.)Execute PID control with PID control instructions by loading an A/D conversion moduleand a D/A conversion module, as shown in Figure 1.1.As shown in Figure 1.1, using the previously set SV (set value) and the digital PV(process value), which is read from the A/D conversion module, PID operation isexecuted to obtain the MV (manipulated value).The calculated MV (manipulated value) is output to the D/A conversion module.The sampling cycle is measured, and the PID operation is performed, when thePIDCONT instruction is executed in the sequence program, as illustrated below.PID operation in accordance with the PIDCONT instruction is executed in presetsampling cycles.MELSEC-Q/QnA2. SYSTEM CONFIGURATION FOR PID CONTROL22. SYSTEM CONFIGURATION FOR PID CONTROLThis section describes the system configuration for PID control using PID control instructions.(For details on the units and modules that can be used when configuring the system, refer to the manual for the CPU module used.)CRTOperation panelD/A conversion moduleA/D conversion moduleMain base unitExtension cableExtension base unitPV (process value) inputFor MV (manipulated value) outputFor PID control monitoring (Only QnACPU)CRT control module AD57 or AD57-S1 onlyQnACPUQCPU High Performance modelPOINT(1) For QnACPU, the reference range for SV, PV, and MV values used in PID operations is 0 to 2000. If the resolution of the A/D conversion module or D/Aconversion module used for input/output in PID control is not 0 to 2000, convert the digital values to 0 to 2000.(2) For High Performance model QCPU, a setting is selectable from fixed values as described in (1) or any appropriate values for the unit used. See Section 4.3.5for details.2.1 Applicable PLC CPUComponent ModuleHigh Performance model QCPU Q02CPU, Q02HCPU, Q06HCPU, Q12HCPU, Q25HCPUQnACPUQ2ASCPU, Q2ASCPU-S1, Q2ASHCPU, Q2ASHCPU-S1Q2ACPU, Q3ACPU, Q4ACPU, Q4ARCPU2. SYSTEM CONFIGURATION FOR PID CONTROLMELSEC-Q/QnA MEMO33. PID CONTROL SPECIFICATIONSThis section gives the specifications PID control using PID control instructions.3.1 Performance SpecificationsThe performance specifications for PID control are tabled below.SpecificationQnACPUItemWith PID Limits for HighPerformance modelQCPU Without PID Limits forHigh Performance modelQCPUNumber of PID control loops—32 loops (maximum)Sampling cycle T S 0.01 to 60.00 sPID operation method—Process value differentiation (normal operation/reverse operation)Proportionate constant K P 0.01 to 100.00Integration constant T I 0.1 to 3000.0 s PID constant setting rangeDifferential constantT D 0.00 to 300.00 sSV (set value) setting range SV 0 to +2000-32768 to +32767PV (process value) setting range PV MV (manipulated value) output range MV-50 to +2050-32768 to +327673.2 Operation ExpressionsThe operation expressions for PID control using PID control instructions are indicated below.NameOperation ExpressionsMeanings of SymbolsNormal operationEV n =PV nf *-SVMV n = MV MV=K p {(EV n -EV n-1)+ EV n - (2PV nf-1-PV nf -PV nf-2)}T S T I T DT SProcess valuedifferentiationReverse operationEV n =SV-PV nf *MV n = MVMV=K p {(EV n -EV n-1)+ EV n + (2PV nf-1-PV nf-PV nf-2)}T ST I T D T S EV n : Deviation in the present sampling cycle EV n-1: Deviation in the preceding sampling cycleSV : Set valuePV nf : Process value of the present sampling cycle (after filtering)PV nf-1: Process value of the preceding samplingcycle (after filtering)PV nf-2: Process value of the sampling cycle two cycles before (after filtering)MV : Output change amount MV n : Present manipulation amount K P : Proportionate constant T S: Sampling cycle T I : Integration constantT D: Differential constant POINT(1) *:PV nf is calculated using the following expression.Therefore, it is the same as the PV (process value) of the input data as long as the filter coefficient is not set for the input data.Process Value after Filtering PV nf = PV n + (PV nf -1-PV n )PV n : Process value of the present sampling: Filter coefficientPV nf-1: Process value of the preceding sampling cycle (after filtering)(2) PV nf is stored in the I/O data area. (See Section 5.2)3.3 PID Control Instruction ListA list of the instructions used to execute PID control is given below.CPU Instruction Name Processing DetailsQ QnAPIDINIT Sets the reference data for PID operation.*1PIDCONT Executes PID operation with the SV (set value) and the PV (process value).*1PID57Used to monitor the results of PID operation at an AD57(S1).×PIDSTOP PIDRUN Stops or starts PID operation for the set loop No.PIDPRMWChanges the operation parameters for the designated loop number to PID control data.*1: For High Performance model QCPU, PID limits can be set to ON or OFF. SeeSections 5.1 and 5.2 for the setting range used in each mode.3.3.1 How to read the instruction listThe instruction list in Section 3.3.2 has the format indicated below:Table 3.1 How to Read the Instruction ListExplanation(1) Classification of instructions according to their application.(2) Instruction names written in a sequence program.(3) Symbols used in the ladder diagram.(4) Processing for each instruction.(5) The execution condition for each instruction. Details are given below.(6) Number of instruction stepsFor details on the number of steps, refer to the QCPU (Q mode) /QnACPU Programming Manual (Common Instructions).(7) A circle indicates that subset processing is possible.For details on subset processing, refer to the QCPU (Q mode) /QnACPU Programming Manual (Common Instructions).(8) Indicates the page number in this manual where a detailed description for theinstruction can be found.3.3.2 PID operation instruction list4.2 PID ControlThe operation methods for PID control with the PID control instructions are the speedmethod and process value differentiation method. The following describes the controlexecuted for both of these methods:4.2.1 Operation method(1) Speed method operationThe speed method operation calculates amounts of changes in the MVs(manipulated values) during PID operation.The actual MV is the accumulatedamount of change of the MV calculated for each sampling cycle.(2) Process value differentiation method operationThe process value differentiation method operation executes PID operations bydifferentiating the PV (process value).Because the deviation is not subject to differentiation, sudden changes in theoutput due to differentiation of the changes in the deviation generated bychanging the set value can be reduced.Either forward operation or reverse operation can be selected to designate thedirection of PID control.4.2.2 Normal operation and reverse operation(1) In normal operation, the MV (manipulated value) increases as the PV (processvalue) increases beyond the SV (set value).(2) In reverse operation, the MV (manipulated value) increases as the PV (processvalue) decreases below the SV (set value).(3) In normal operation and reverse operation, the MV (manipulated value) becomeslarger as the difference between the SV (set value) and the PV (process value)increases.(4) The figure below shows the relationships among normal operation and reverseoperation and the MV (manipulated value), the PV (process value), and the SV(set value):(5) The figure below shows examples of process control with normal operation andreverse operation:4.2.3 Proportionate operation (P operation)The control method for proportionate operation is described below.(1) In proportionate operation, an MV (manipulated value) proportional to thedeviation (the difference between the set value and process value) is obtained.(2) The relationship between E (deviation) and the MV (manipulated value) isexpressed by the following formula:MV=Kp • EKp is a proportional constant and is called the "proportional gain".(3) The proportionate operation in step response with a constant E (deviation) isillustrated in Fig. 4.2.(4) The MV (manipulated value) changes within the range from -50 to 2050 or theuser-defined range (for High Performance model QCPU only).The MV (manipulated value) in response to the same deviation becomes largeras Kp becomes larger, thus the compensating motion is greater.(5) The proportionate operation is always associated with an offset (offset error).4.2.4 Integrating operation (I operation)The control method for integrating operation is described below.(1) In the integrating operation, the MV (manipulated value) changes continuously tozero deviation when it occurs.This operation can eliminate the offset that is unavoidable in proportionateoperation.(2) The time required for the MV in integrating operation to reach the MV forproportionate operation after the generation of deviation is called the integratingtime. Integrating time is expressed as T I.The smaller the setting for T I, the more effective the integrating operation will be.(3) The integrating operation in step response with a constant E (deviation) isillustrated in Fig. 4.3.(4) Integrating operation is always used in combination with proportionate operation(PI operation) or with proportionate and differentiating operations (PID operation).Integrating operation cannot be used independently.4.2.5 Differentiating operation (D operation)The control method for differentiating operation is described below.(1) In differentiating operation, an MV (manipulated value) proportional to thedeviation change rate is added to the system value to zero deviation when itoccurs.This operation prevents significant fluctuation at the control objective due toexternal disturbances.(2) The time required for the MV in the differentiating operation to reach the MV forthe proportionate operation after the generation of deviation is called thedifferentiating time. Differentiating time is expressed as T D.The smaller the setting for T D, the more effective the differentiating operation willbe.(3) The differentiating operation in step response with a constant E (deviation) isillustrated in Fig. 4.4.(4) Differentiating operation is always used in combination with proportionateoperation (PD operation) or with proportionate and integrating operations (PIDoperation).Differentiating operation cannot be used independently.4.2.6 PID operationThe control method when proportionate operation (P operation), integrating operation (Ioperation), and differentiating operation (D operation) are used in combination isdescribed below.(1) During PID operation, the system is controlled by the MV (manipulated value)calculated in the (P + I + D) operation.(2) PID operation in step response with a constant E (deviation) is illustrated in Fig.4.5.4.3 PID Control FunctionsDuring PID control using the PID control instructions, MV upper/lower limit control isautomatically executed by the bumpless changeover function explained below.4.3.1 Bumpless changeover functionThis function controls the MV (manipulated value) continuously when the control modeis changed between manual and automatic.When the control mode is changed between manual and automatic, data is transmittedbetween the MV area for automatic mode and the MV area for manual mode.The control mode is changed in the input/output data area (see Section 5.2).(1) Changing from the manual ...........mode to the automatic mode The MV in the manual mode is transmitted to the MV area for the automatic mode.(2) Changing from the automatic .......mode to the manual mode The MV in the automatic mode is transmitted to the MV area for the manual mode.POINT(1) Manual and automatic modes of PID control:1) Automatic modePID operation is executed with a PID control instruction.The control object is controlled according to the calculated MV.2) Manual modePID operation is not executed. The MV is calculated by the user and thecontrol object is controlled according to the user-calculated MV.(2) The loop set in the manual mode stores the PV (process value) in the set valuearea every sampling cycle.4.3.2 MV higher/lower limit control functionThe MV higher/lower limit control function controls the higher or lower limit of the MVcalculated in the PID operation. This function is only effective in the automatic mode. Itcannot be executed in the manual mode.By setting the MV higher limit (MVHL) and the MV lower limit (MVLL), the MVcalculated in the PID operation can be controlled within the range between the limits.When the MV higher/lower limit control function is used, the MV is controlled asillustrated above.A MVHL (manipulated value higher limit) and MVLL (manipulated value lower limit)takes on a value between -50 and 2050 or a user-defined value (for High Performancemodel QCPU only).The following are the default settings:• Higher limit................2000 (Or user-defined value)• Lower limit................0 (Or user-defined value)The value set for the higher limit must not be smaller than the value set for the lowerlimit.An error will occur if it is.4.3.3 Monitoring PID control with the AD57(S1) (QnACPU only)The PID control operation results can be monitored in a bar graph with an AD57(S1)CRT controller unit.(1) The monitor screen displays the monitored information of eight loops beginningwith the designated loop number.POINTThe SV, PV, and MV present value are displayed as percentages of 2000.1) SV percentage display...............SV2000100 (%)2) PV percentage display...............PV2000100 (%)3) MV percentage display...............MV2000100 (%)(2) Use the PID57 instruction to execute monitoring with an AD57(S1).See Section 8.3 for details on the PID57 instruction.4.3.4 Function for transfer to the SV storage device for the PV in manual modeThe PIDCONT instruction is also executed in manual mode.In the manual mode, it ispossible to select whether or not the PV input from the A/D conversion module onexecution of the PIDCONT instruction is transferred to the SV storage device or not inaccordance with the ON/OFF status of the PID bumpless processing flag (SM774).• When SM774 is OFF : When the PIDCONT instruction is executed, the PV istransferred to the SV storage device.On switching from the manual mode to the automaticmode, the MV output is continued from the value in themanual mode.After switching to the automatic mode, control can beswitched from the MV that was being output to the SV bychanging the SV.• When SM774 is ON : When the PIDCONT instruction is executed, the PV is nottransferred to the SV storage device.On switching from the manual mode to the automaticmode, control can be switched from the MV output in themanual mode to the SV.Before switching to the automatic mode, store a SV in theSV storage device.POINTWhen SM774 is ON or OFF, switching from the manual mode to the automaticmode may cause different control effects as follows.• When SM774 is OFF, the PV is transferred to the SV storage device.When the manual mode is switched to the automatic mode, no difference iscaused between the PV and the SV and the MV does not change rapidly, exceptthat the SV differs from a target value defined in the automatic mode.Use the sequence program to make step-by-step adjustments to the SV so thatthe SV approaches closer to the target value.See sample programs in Section 9.3.• When SM774 is ON, the PV is not transferred to the SV storage device. This maycause a difference between the PV and the SV when the manual mode isswitched to the automatic mode.A greater difference may cause the MV to change rapidly. So this procedure isused for systems in which the manual mode can be switched to the automaticmode only when the PV approaches closer tothe SV.The automatic mode can be effected without using the sequence program tomake step-by-step adjustments to the SV.REMARKThe SV and PV are stored in the devices in the I/O data area designated by thePIDCONT instruction.4.3.5 Changing the PID Control Data or Input/Output Data Setting Range (HighPerformance model QCPU Only)For High Performance model QCPU, setting ranges can be selectable for PID controldata (see Section 5.1) and input/output data (see Section 5.2). To effect the user-defined setting range, designate the loops for which PID limit settings (SD774 and SD775) are defined, and then set these loops' bits to ON before executing the PIDCONTand PIDINT instructions.SD774SD7750 : PID Limit ON (default setting)1 : PID Limit OFF (user-defined setting)A "PID Limit OFF" setting does not effect the limit control over internal data. To effectthe limit control, execute the processing by operating from the user's application side.。
三菱系列变频器PID控制参数设置及校正
三菱系列变频器PID控制参数设置及校正三菱变频器PID控制图三菱FR-F700系列变频器PID控制参数调节及校正对象：FR-F740 + 远程压力表（0－1.6MPa）＋控制电机控制方式：从PU板输入目标数值，通过压力表输入实时压力测量值，变频器自动调节输出频率一、硬件设置1 短接RT和SD端子，使X14端子为ON ,。
2 短接AU和SD端子,3 将拨码开关置1，出厂时默认设置为0。
二、接线图三、参数设置·为了进行PID控制，请将X14信号置于ON。
该信号置于OFF 时，不进行PID动作，而为通常的变频器运行。
（但是，通过LONWORKS，CC-Link通讯进行PID控制时，没有必要将X14信号置于ON。
）·在变频器的端子2-5间或者Pr.133 中输入目标值，在变频器的端子4-5间输入测量值信号。
此时，Pr.128 请设定为“20或者21”。
·输入在外部计算的偏差信号时，请在端子1-5间输入。
此时，Pr.128 请设定为“10或者11”。
参数表：Pr.128＝20（PID负作用）Pr.183＝14（PID控制选择）Pr.267＝1或2（4号端子输入电压选择，1时为0－5VDC；2时为0－10VDC）Pr.133=设定目标值（也可以从2号端子输入，详见说明书）四、参数校正将上述参数设置完成以后，保证RT端子和AU端子均和SD端子短接后，再进行参数校正。
将压力表值调节到0MPa，设置参数Pr.c6＝0；将压力表值调节到1.6MPa，设置参数Pr.c7＝100.这样，0－100将和0－1.6MPa等比例对应，目标值设定Pr.133中设定值（0－100）与0－1.6MPa等比例对应。
1 调整步骤2 详细校正过程（1）按变频器PU板上的MODE键，调至参数选择界面，如图：，然后旋转旋钮使界面到Pr.C参数设置界面，如图：，再按SET键进入参数号选择界面，如图：，此时字母C后的光标闪烁。