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1,ST Language,Basic Course,2,ST Language,Key word If there is any unclear or uncorrected, please feel free to speak out,Basic Course,3,Requirements,Hardware The programming language ST is only available for following programmable controllers:,pCO3 Supernode pCO5 pCO compact,BIOS To support ST language, bios version must greater than 5.0,Software Use a version of 1tool = 2.1.x,4,Creation of a solution ST Language,Choosing : - FBD, the application will be mixed, it will consist of a main with Atoms, Macroblocks . but you can use routines (functions and function blocks) written in the ST - ST, the application will be developed entirely using ST language,5,Basic concepts,When programming in ST, the application can be organised using three fundamental programming elements generically called Program Organization Units (POU): PROGRAM FUNCTION FUNCTION BLOCK,POU,Note: we can define more functions and function blocks, but only one program main,6,The basic types,The following table lists all the properties of basic types (IECType):,7,Declaration of Global variables,There are two ways to declare Global variables: Variable List Textual mode of ST language,Note: if you want to see the variable in the pGD, please declare the variable in the Variable List,8,Assignment operator :=,Syntax,Assign to a variable:,a constant value the value of another variable the result of an expression.,Varaible_name := expression ;,Note: there is a ; in the end of statement,9,Textual declaration,To declare variables in ST you have to use the following declaration block:,Note: 1. there is no ; in the end of END_VAR; 2. we can give the default value in the declaration.,10,Rules of the identifiers (variables name),az, AZ 09 _,The name of an identifier (variable or constant) can be any combination (see Example) of the characters listed below:,Example Rules to create identifiers.,11,The qualifier CONSTANT,Textual declaration of Constants,The keyword CONSTANT can declare a constant. The constants do not occupy space in memory as the variables During compilation instead of the constant is replaced a numeric value.,12,Comments,Comment using keyword REGION ENDREGION You can hide several lines of code using the keyword REGION ENDREGION. So increase the readability of the code on the screen. The code is replaced with a comment. Clicking on comment it will appear again the code.,The code comments You can use two ways to make a comment To comment a single code line use “” To comment more code lines use “(*” and “*)”,There is no _ in between END and REGION,13,The qualifier RETAIN,Textual declaration of global variables REATAIN (retentive),Example,Declaration of retentive Global variables.,RETAIN keyword declares a variable in T-permanent memory.,Organization of the variables.,Note: pay attention of the default value,14,Cast Functions,Syntax,Variable_name := *_TO_*(value);,The conversion functions are used to convert any of the elementary data types to any other. They must be used to make the data type uniform before a function, where this is required.,15,ST operators,For the evaluation of expressions, always use brackets, this avoids errors in the evaluation of the expressions.,Example,Table of the operators priority,An expression is executed only after the evaluation of the operators priority. The execution order of an expression and its result are influenced by the operators priority.,Suggestion,A:= NOT X AND Y OR NOT J; Increases readability: A:= NOT(X) AND (Y OR (NOT J);,If Z=0 the other variables have not been evaluated. A := Z AND Y AND (NOT J);,16,Conditional statements: IF,IF THEN ELSE statement Conditional construct: executes a statement block depending on whether or not certain conditions are satisfied.,Syntax,Exercize,If Expression=TRUE, statement_block is executed Otherwise the conditions in the ELSIF blocks are evaluated Finally, if these are all false, the statements in the ELSE block are executed.,Boolean (AND, OR, NOT, XOR) Comparison (=, , , =, , =).,Features,IF expression THEN statement_block; ELSIF expression THEN statement_block ; ELSE statement_block ; END_IF;,Note expression contains the operators:,Management of a range -550,950 C with NTC probe.,17,Conditional statements: CASE,CASE OF statement,Syntax,Conditional construct: selects the statements to be executed depending on the value of an integer expression.,CASE expression OF selector_1 : statement_block; selector_2, selector_3 : statemnt_block; selector_4 selector_5 : statemnt_block; selector_6, selector_7 selector_8 : statemnt_block; ELSE statemnt_block; END_CASE;,Example,Speed management of a fan.,18,The Function,It can be comparable to a Black box: it works on a Input parameters configuration, and it always produces in Output the same result for the same Inputs. It lets not repeat many times the same code within the project, as instead it is for macroblocks in FBD environment. At each invocation of the function, the same code will be always executed.,What does a Function do?,It read Inputs, no outputs, but can have a return value It executes the code of the function It writes the result in a Return Value A function doesnt have a memory state It always produces the same result for the same inputs.,The function Add_3,What does a Function contain?,The list of parameters that are passed as inputs Probable Local variables, only for its internal use The code of the function,What is a Function?,19,FUNCTION statement,The table below lists all properties of a function.,Summary,20,Pass by value (VAR_INPUT),In the pass by value the Actual Parameters are copied in Formal Parameters.,Actual Parameters,Formal Parameters,Modifications dont have effect on Actual Parameters.,21,Pass by Reference (VAR_IN_OUT),Pass by Reference,Actual Parameters,Formal Parameters,Modification,Sometimes it is necessary to modify the variable value passed to the function, and render such modification outside immediately visible. This modality is called Pass by Reference and it is realized using keyword VAR_IN_OUT. In Pass by Reference the Formal Parameter point to the same cell of memory that contains the value of Actual Parameter.,22,Variables scope,23,RETURN statement,Syntax,The RETURN statement is used to exit from a Function, Function Block or the Program before the end.,FUNCTION My_function list_statements_1; RETURN; list_statements_2; END_FUNCTION,1st Example,2sd Example,In the case of a Function or Function Block, the statement interrupts execution after list_statements_1, and passes control to the calling POU without executing list_statements_2. In the case of the Program, the statement closes the Program.,24,ARRAY statement,Syntax,Exercize,Array_name: ARRAYelem_1elem_n OF Type; where:,Simulation,elem_1 and elem_n are INT numbers or constants (they cannot be variables) and represent the limits of the array elem_n = elem_1, the difference +1 indicates the number of elements in the array Type identifies the elementary data type elements inside the array or Structure type,25,Array Breakthrough (exceeded limits),Example,Run-Time error on Simulator,Run-Time error on pCO Place 2 integer variables on a Mask related to library functions: The position of error in the Strategy Editor ST: go in simulation and then press insert High part and Low part,When a variable is used to access the elements of an array, care must be paid to ensure the size of the array is not exceeded. If run-time the index value exceeds the size of the array, this will entail the re-boot of the pCO.,Note To reset error variables use this library functions:,26,Iteration statements: FOR,FOR DO Statement,FOR variable := initial_expression TO final_expression BY increase_expression DO statement_block; END_FOR;,FOR loop executes a statement block from an initial value to a final value of the control variable.,Syntax,Example,Counter=10,27,Iteration statements: WHILE,WHILE DO Statement,WHILE statement executes a statement block while the expression is true.,Syntax,WHILE expression DO statement_block; END_WHILE;,Example,To search for an element within an array.,28,Iteration statements: REPEAT,REPEAT UNTIL Statement,REPEAT statement_block; UNTIL expression END_REPEAT;,The statements contained in the loop are executed at least once.,REPEAT statement executes a statement block while the expression is true. The loop is executed at least once.,Syntax,29,Iteration statements: EXIT,Syntax,1sh Example,EXIT statement,To exit by for loop.,EXIT;,The EXIT statement is used exclusively inside WHILE, REPEAT, and FOR statements to interrupt execution of the loop and go to the statement after the end of the loop (END_FOR, END_WHILE, END_REPEAT).,2sd Example,To exit by nested for loop.,30,Iteration statements,Note: Compare statement While Do and Repeat Until; Compare statement Return and Exit.,31,n-dimensional Array,Syntax,Exercize,Simulation,Note:,Array_name: ARRAY el_1el_n, el_1el_m OF Type;,The rules seen for one-dimensional arrays are valid The syntax is used to declare a matrix To access array elements, nested FOR loops can be used (see exercize),32,The fields of a structure can be of elementary type, of type structure, Array, n-dim Array, not Array of structures A structure must be instanced, before to be used, in such way comes reserved in memory the necessary space to its data. The space occupied by a structure is given by the sum of the space occupied by each single fields. In order to access/to modify single fields of a structure the . is used (e.g.: Room_Temp.Temperature). It is possible to assign a structure to another, thus realizing the copy of the data. Remember the two instances must be of the same type (such as the Arrays).,The data type Structure,The structures are used in order to create more complex user types, of the normal elementary types. A structure is a data type that contains a predefined number of fields, usually of different types.,33,TYPE STRUCT statement,Allows to define the data type structure.,Definition syntax TYPE structure_type : STRUCT field_1_name : data_type; field_n_name : data_type :=value; END_STRUCT; END_TYPE,Instance delaration sysntax VAR_GLOBAL my_struct1 : structure_type; my_struct2 : structure_type :=(field_1_name:=value, fiel_2_name:=value); END_VAR,Example,In simulation it is possible to visualize the instances,Build two structure Cmpr_Info.,34,FUNCTION BLOCK,It uses the potentialities of a function and those of a structure. It can be thought as a Black Box endowed of: Input Parameters (pass by Value) or Input_Output Parameters (pass by Reference) Output Parameters Local Variables (accessible only within the FB) It is a object and has a internal memory state Note: Functions dont have memory A FB must be instanced before use, in such way the FB comes statically allocated by the controller in Ram Memory, in order to reserve the space for its data It is possible to define more instances of the same FB, but the code contained in the application is unique.,What is a Function Block?,Example,Use TON timer in order to activate relay n1 after 2 second.,Use . to access to FB elements:,Use = to write on a variable the FB outputs.,Use := to assign value to the input.,35,FUNCTION BLOCK,Function Block instance Local variables (VAR), are allocate/deallocate inside Stack at every calling of: Program Function A Function Block instance should be declared Global (VAR_GLOBAL) and not Local (VAR). A instance of FB that is declared Local (VAR) could have a different behaviour from that expected.,Example In this example a Globale and Local instance of TON are declared. The Local instance will never succeed to finish the count, because of the internal management of the Local variables.,36,FUNCTION_BLOCK instance,FUNCTION_BLOCK functionblock_name (* Input, In_Out, and Output variables declaration *) (* Local variable declaration *) (* Implementation code*) END_FUNCTION_BLOCK,Definition synstax,A Function Block:,can be called more than once inside a Program, a Function or a Function Block receives one or more input values (VAR_INPUT or VAR_IN_OUT) and unlike Functions, gives one or more output values (VAR_OUTPUT). the values of the Local variables (VAR) and the input and output parameters in Function Blocks are saved in the memory between calls of the function block, and from one program cycle to the next; in the latter case as long as the function block instance has been declared as Global (VAR_GLOBAL).,In the calling POU the instance of the function block must be declared FIRST, so as to allocate the memory required to store the values of the internal variables (e.g.: use VAR_GLOBAL; take care if using VAR). If one of the input parameters is omitted (VAR_INPUT), the function block uses the default value (0 or FALSE in the first program cycle) or the last value used inside the function block. Parameters declared as VAR_IN_OUT cannot be omitted. Recursion is not allowed.,37,FUNCTION_BLOCK instance,Recursion,Recursion is not allowed, that is a Function Block cannot:,refer directly refer indirectly call a Function or Function Block instance that refer it.,Direct recursion,Indirect recursion,38,FUNCTION_BLOCK instance,Variables scope:,The qualifier RETAIN,If a Global instance has the qualifier RETAIN, data are saved in T-permanent memory.,39,The properties of a block are listed below.,FUNCTION_BLOCK: Summary,40,ST event is a function with the following restrictions: Has a unique name Has no Return value Has no Input parameters Has no Local variables Can only modify Global variables, you can not call Functions or Function Blocks Event differs from other functions, because the name is preceded by the reserved word Event_ (e.g.: Event_incA) There is no limit to the number of events that you can define. Syntax FUNCTION Event_NameEvent /CODE END_FUNCTION From Mask Editor is possible to execute a ST event, specifing in the Key Function Editor Do_ST_Event statement. Example When the PRG button is pressed, increase a variable. 3 How? In the Startegy Editor ST define the event In the Key Function Editor with DO_ST_Event statement call the event,ST Event,41,How to use the Add_3 in FBD? In the Solution Explorer add a page to Subroutine ST node Edit Add_3 function code, paying attention to types of Input parameters and Return value. In the Dependencies node of Solution Explorer add Core_ST library. Inside FBD environment From Core_ST library select ST_Call atom to call Add_3 function inside FDB environment. Finally connect variables to pins.,FBD and ST environment,Reminders on FBD environment FBD Environment uses only the basic types (Boolean, Integer/Analog) The ST language is supported by some controllers (pCO3, Suprnodo, ),42,FBD and ST environment,How do you change firm of your Function or Function Block in FBD Strategy Editor? In FBD Startegy Editor I have placed My_Add function, but i have to add an other parameter You have to add the new parameter to My_Add function, and then, you have to select “Update from firm” in FBD Strategy Editor,1st step Add In3 to My_Add function,2sd step In FBD Strategy Editor “Update from firm”,3rd step In FBD Strategy Editor connect _In3 variable,43,System variable,ST Language uses specific library functions, in order to access to system variables of type: Boolean Integer Syntax Set_SystemVariableName (Vaule); Variable := Get_SystemVariableName ( ); 1st Example (Boolean) Set_KEY_PRESSED(1); Alarms:= Get_GLOBAL_ALARM( ); 2sd Example (Integer) Set_KEY_PRESSED(1); BMSAddr := Get_BMS_ADDRESS( ); Library access To access library functions press CONTROL+SPACE,44,Base 2, Base 8 and Base 16,A number can be represented also in the bases: Binary (Base 2) Octal (Base 8) Hexadecimal (Base 16) Syntax Variable := Base#Value; Example a:=2#10110001; a:=8#767; a:=16#AF0; Moreover, it is possible to separate the figures with of optional _ , in order to increase the readability a:=2#1011_0001; a:=8#7_6_7; a:=16#AF0; a:=16#A_F_0;,45,Arithmetc statements,ST language can use the following arithmetic operations:,2sd Esempio The use of division operator.,1st Example Arithmetic operator:,46,Numerical statements,Vedi anche,Language ST allows to use the following numerical statements:,47,Debug,There are two types: Conditional Breakpoint Breakpoint During the simulation Breakpoints are not active on: Functions never call Variables/Instances never use Example,For debugging the application use the breakpoint.,Debugging keys F5: goes to next breakpoint Control+F10: Step over Control+F11: Step into Control+Shift+F11: Step out,48,Exercises,Ex1: 在ST中进行浮点数运算。 控制逻辑: 对数学表达式进行运算： A= (IN1+1) / (IN2+1) B= -0.024263A2 + 0.8638A + 0.16655 Vw= -0.0922B2 + 1.154B 具体要求: 在Subroutine ST中编写一个函数块，最终在FBD中调用该函数。分别 给IN1和IN2赋两组数据，看最终Vw的值是否为计算的最终结果。 参考: 需要用到的相关语句：+，-，*，/, *, INT_TO_REAL,REAL_TO_INT.,49,Exercises,Ex2: 使用ST语言写出机组开关机的功能块。 控制要求: 以功能块（Function block）的形式编写该模块 在FBD中调用该功能块 具体要求 功能块的输入 根据机组启动请求来管理机组状态，机组启动的选择方式如下： 通过键盘Keyboard_OnOff 通过plan pLan_OnOff 通过数字量输入Dig_In_OnOff，En_Dig_In_OnOff 通过时间段Schedule_OnOff，En_Sched_OnOff 通过上位机Superv_OnOff，En_Superv_OnOff 通过报警状态 Alarms 功能块的输出 变量Unit_OnOff 表示机组的状态。仅当上述功能全部启用，即以下全部条件均为真时（Unit_OnOff=1）： Keyboard_OnOff=1 pLan_OnOff 或En_PLan_Onoff=0 Dig_In_OnOff=1 或 En_Dig_In_OnOff=0 Schedule_OnOff=1 或 En_Sched_OnOff=0 Superv_OnOff=1 或 En_Superv_OnOff=0 Alarms=0 功能块的输入Manual 对机组状态不起作用，仅对输出 Unit_Status 起作用。 功能块的输出 Unit_Status 表示机组的运行状态。 Unit_Status 的值状态0机组开启(Unit_OnOff=1)1Alarms=02机组因报警而关闭(Alarms=1)3机组通过plan关闭（ pLan_OnOff 且En_PLan_Onoff）4机组通过上位机关闭（Superv_OnOff=0 且 En_Superv_OnOff=1）5机组通过时间段关闭（Schedule_OnOff=0 且 En_Sched_OnOff=1）6机组通过数字量输入关闭（Dig_In_OnOff=0 且 En_Dig_In_OnOff=1）7通过本地键盘关闭机组(KeyBoard_OnOff=0)8手动操作(Manual=1)请注意，如果同时出现 2 个或多个上述情况，输出 Unit_Status 将取最大值。例如，如果机组由于报警关闭，并同时通过数字量输入关闭，则 Unit_Status 的值为 6。 功能块的输出 Led_OnOff 提供 LED 的状态，该 LED 表示机组状态。 LED_OnOff 的值状态0通过键盘关闭机组 (KeyBoard_OnOff=0)1机组开启 0/1在每个程序周期中，该值从 0 变为 1，再从 1 变为 0。机组由于报警关闭，Plan关闭或通过上位机、时间段或数字量输入关闭。,50,Exercises,Ex3: 利用ST编写Pumpdown管理模块 要求： 要求编写的ST模块与标准库中Pumpdown模块具有相同的功能。 步骤： 创建一个FBD的工程，利用ST语言编写function block 编写具有F_Edge功能的function block 编写具有Delay功能的function block 完成Pumpdown功能的逻辑控制 将利用ST编写的Pumpdown模块和标准库中的Pumpdowm模块同时拖放到 Strategy中，连接变量测试 相关ST语句： 可能用到的function block有F_Trig， SR， TON Note： 使用的F_Edge和Delay需要自己编写function block来实现。,51,Exercises,Ex4: A simple control 要求: 利用ST语言完成简单控制，包括读取温度值，风扇控制，压缩机控制，报 警管理，输出变量值，界面显示等。 步骤: 创建一个ST的工程，利用ST语言编写function 编写具有自动回到主界面功能的function 编写具有读取模拟量，数字量功能的function 编写具有风扇控制功能的function 编写具有压缩机控制功能控制的function 编写具有报警管理功能的function 编写具有变量值输出功能的function 完成用户界面的显示功能,52,Exercises,具体控制: 当程序中没有进行任何操作，60s后自动回到主界面。 模拟量B1读取室内温度的值。数字量Din1为系统开关，0表示开，1表示关，Din2和Din3分 别为压缩机的高压报警输入和低压报警输入；模拟量输出Y1为压缩机根据室内温度输出电压 值，在室内温度范围34度（压缩机设点减去偏差，偏差1度可设）和36度（压缩机设点加偏 差，偏差1度可设）输出0.2v（可设）到2.2v（可设）；模拟量输出Y2为当压缩机开启时有 一个值输出10v（可设），当压缩机关闭时有一个值输出3.5v（可设）。 冷凝风机管理利用室内温度使用如下控制曲线： 控制曲线 温度设点60度（可设），Diff_Off为3度（可设），Diff_On为0。同时只要压缩机启用，则 冷凝风机也开启。 蒸发风机管理利用室内温度使用如上控制曲线： 温度设点为-15度（可设），Diff_Off为3度（可设），Diff_On为0 压缩机管理利用室内温度使用如上控制曲线曲线： 温度设点为35度（可设），Diff_Off为2度，Diff_On为0。 报警管理： 具有高低温，和高低压报警管理。当温度大于60度（可设）高温报警，小于55度（设点减偏差，偏差5度 可设）可消除报警；当温度低于-15度（可设）低温报警，大于10度（利用和高温报警相同的偏差）可消 除报警；高低压报警由数字量输入。,53,
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