FlexSim Supplemental Training: Session 4

1. FlexSim Supplemental Training: Session 4 20121029

2. Session Philosophy Increase your modelling power through: Knowing where and how model data is stored/accessed Reusability Abstraction Be able to ask yourself: What Event and what Object will allow me to accomplish what I want? 2

3. The Flexsim Tree and Flexscript Trees and Nodes Functions Understanding Modeling events The Modelling Language – Flexscript Model building 3

4. What is a Node? Basic data structure of Flexsim is a hierarchal tree main tree (model and project related objects and data) view tree (GUI related objects and picklists) model tree (model related objects and data) The node is the basic building block of a tree Nodes hold all the information behind the scenes for objects, GUIs and data. 4

5. Node Structure Nodes have a name Nodes can have a data item number string object If nodes have object data, use > to view a separate node list containing the object info (data members and member functions) If nodes contain sub nodes, use + to expand and view the child nodes 5

6. Node Symbols Standard Folder Object Object data Function (C++) Function (FlexScript) 6

7. Sample Model Tree 7

8. What is a function? functionname(argument1, argument2, etc) An argument can be: Numerical value String (“text“) Reference to an object or node Function example: colorrandom(item) (see OnExit trigger of a Source object) Many of Flexsim’s functions are used to read data from the tree and save data to the tree. 8

9. Functions and the ‘return’ statement • Function ‘calls’ are like asking a question • Input is required of the user and an answer is given as a ‘return’ value • Picklist properties on Objects are functions • The return values will mean different things for each object function, it answers the question asked by the function

10. Object Properties Understanding the edit fields of an object will help you understand Flexsim. You should be able to answer the following four questions about each edit field: what is its purpose? when is it evaluated? what are its access variables? what does it return? 10

11. Order of Execution(pushed flowitem) flowitem enters OnEntry Setup Time Pick Operator delay Pick Operator Process Time OnSetupFinish delay OnProcessFinish Send To Port possible delay delay OnExit Request Transport From 11

12. Access Variables & Returns 12

13. General Rules language is case sensitive (A does not equal a) no specific format is required (free use of spaces, tabs and line returns are encouraged for readable code) text strings are entered between quotes. “mytext” parenthesis follow a function call and commas separate the arguments of the function. moveobject(object1, object2); a function or command will always end with a SEMI-COLON (;) parenthesis can also be used freely to make associations in your math and logic statements. Ex: ((x+3)*2) curly braces { } are used to define a block of statements. to comment the rest of a line use // and type note here multi-line comments start with /* and end with */. don’t use spaces or special characters in name definitions ( _ is ok). names may include numbers, but may not begin with a number (machine_9 is acceptable, 9machine is not). 13

14. Variable Types int double string treenode integer (1, 2, 3, 14324) double precision (2.5, 3.14159) text string (“Anthony was here.”) reference to a node in the tree 14

15. Declaring and Setting Variables int index = 1; double weight = 175.8; string category = “groceries”; treenode forklift = centerobject(current,1); 15

16. Math Operators x + y x - y x * y x / y sqrt(x) pow(x,y) round(x) frac(x) fmod(x,y) min(x,y) max(x,y) x plus y x minus y x times y x divided by y square root of x x to the power of y (xy) x rounded to the nearest integer returns the decimal portion of x returns the remainder of x/y returns minimum of x and y returns maximum of x and y 16

17. Comparing x > y x < y x >= y x <= y x == y x != y comparetext(string1,string2) x greater than y x less than y x greater than or equal to y x less than or equal to y x equal to y x not equal to y string1 matches string2 • These values return TRUE or FALSE. 17

18. Updating x = y x += y x -= y x *= y x /= y x ++ x -- set x to y set x to x plus y set x to x minus y set x to x times y set x to x divided by y add 1 to x subtract 1 from x • Remember: ‘=‘ is not the same as ‘==‘ • = is used to set a value • == is a comparison operator 18

19. Relating && || ! logical AND logical OR logical NOT 19

20. Logical ‘if’ Statement if (test expression) { code block } else { code block } if (content(item) == 2) { colorred(item); } else { colorblack(item); } 20

21. switch (switchvariable) { casecasenum: { code block break; } casecasenum2: { code block break; } default: { code block break; } } Logical ‘switch’ Statement int type = getitemtype(item); switch (type) { case 1: { coloryellow(item); break; } case 5: { colorred(item); break; } default: { colorgreen(item); break; } } 21

22. Basic Object Referencing current - the current object, the owner of the code item - the involved flowitem that triggered the event model - references the model tree rank(node, ranknum) rank(current,3) first(object) first(current) last(object) last(current) inobject(object, portnum) inobject(current,1) outobject(object, portnum) outobject(current,1) centerobject(object, portnum) centerobject(current,1) node(“relativepath”, object)node(“/Operator1”,model()) 22

23. Basic Object Statistics content( object ) getinput( object ) getoutput( object ) getstatenum( object ), setstatenum( object, value ) int inventory = content(current); int produced = getoutput(current); 23

24. Accessing Data in the Tree • getvarnum(object, “varname”), setvarnum(object, “varname”, value) • getvarstr(object, “varname”), setvarstr(object, “varname”, string) • getvarnode(object, “varname”) • getnodenum(node), setnodenum(node, value) • getnodestr(node), setnodestr (node, string) • labels(object) • itemtype(object) Many nodes are arranged as tables within objects and can also be accessed with the table commands • gettablenum(ReferenceToTable, row, col), settablenum() etc.

25. Logical ‘while’ Statement while (test expression) { code block } while (content(current) > 0) { destroyobject(last(current)); } In programming, a while loop is a control structure that allows a code block to be repeated as long as a test expression is true. May also use the break or return statement to force loop execution to halt. Avoid infinite loops by ensuring that the test expression will eventually fail. 25

26. Logical ‘for’ Statement for (int index=1; index<=content(current); index++) { colorblue(rank(current,index)); } for (start expression; test expression; count expression){ //code block} A for loop allows you to repeat a block of code a set number of times. The head of the for loop defines the repeat conditions: 1. specify a changing variable & give it an initial value 2. set a condition to exit the loop 3. how to treat your variable at the end of each iteration Avoid infinite loops by ensuring that the test expression will eventually fail. 26

27. Model Key Concepts • Logic Control via Loops and Conditional statements • Locating, and manipulating data from the Tree, ex. how does the Combiner know how many flowitems to pack? • Combiner component list table shows target quantities from each input port • Additional node in its tree called targetcomponentsum which is the sum of all target quantities from all input ports. The cumulative number of flowitems to pack across all ports. • If you need to alter the combiner’s component list dynamically, you need to adjust both values; the value from each port, and the sum of all ports

28. Model Description Purpose Practice using FlexScript to accomplish various modeling needs, such as routing, decision making and object manipulation. Description 4 item types, distributed according to the duniform distribution, enter a conveyor, and are routed to 1 of 2 object groups consisting of a queue, pallet source and a combiner. Write a Send to Port rule that will send 70% of the flowitems to the queue on port 1, and the rest to port 2. Combiners will read a Label value off of pallets and pack that many flowitems into the pallet. The label value will vary according to duniform(3, 12). Assume an infinite supply of pallets from the pallet source. Loaded pallets are sent to a processor where they will process for a length of time equal to the lognormal2(15, 3.1, 0.5) times the number of flowitems on the pallet. Change the color of the boxes inside the pallet according to their itemtype, as they leave the processor. Arrange the colors such that itemtype 1 = green, 2 = red, 3 = orange, and 4 = blue. Send pallets to the appropriate sink such that if they have less than or equal to 6 items they go to sink 1 the rest to sink 2. 28

29. Model Layout 29