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Omron IPC Machine Controller Industrial Panel PC / Industrial Box PC. Software User’s Manual (Industrial PC Platform NY-series) - page 7

5 Designing Tasks

Performing Motion Control with Motion Control Instructions

Motion control instructions access the Servo Drives and encoder input slaves to which axes are

assigned.

For NY-series Controllers, motion control instructions can be used in the primary periodic task and in a

priority-16 periodic task.

In either case, the motion control instructions are processed in the motion control processing (MC) sec-

tion of the primary periodic task.

The I/O response times that include EtherCAT communications times are given below.

z

Programming Motion Control Instructions in the Primary Periodic Task

The motion control instructions are processed in the next motion control processing (MC) section of

the primary periodic task. The results of processing are output via EtherCAT communications to the

Servo Drive to which the axis is assigned during the I/O refresh period in the next primary periodic

task.

The Controller makes a response in the following I/O response time.

I/O response time = Primary period (= process data communications cycle)

Slave A

Servo A

IN

Execution command

Process data

communications cycle

= Primary period (t)

Primary period (t)

IO

UPG MC

IO

UPG MC

IO

UPG MC

Primary periodic

task

FB

Motion control

Processing is performed in the

instructions

Commands to Servo A are sent via

motion control processing (MC)

executed.

EtherCAT communications when I/O is

section in the same primary period.

refreshed in the next primary period.

Task period 1 (e.g., t × 3)

Priority-16

UPG

periodic task

Note: The above diagram shows only one input and one output.

However, the I/O response time may be as follows depending on the timing of the input from the

slave.

Maximum I/O response time = Primary period (= process data communications cycle) × 2

5-64

5 Designing Tasks

z

Programming Motion Control Instructions in the Priority-16 Periodic Task

The motion control instructions are processed in the next motion control processing (MC) section of

the primary periodic task after the priority-16 periodic task. The results of processing are output via

EtherCAT communications to the Servo Drive to which the axis is assigned during the I/O refresh

period in the next primary periodic task.

The Controller responds in the following I/O response time regardless of the execution timing of the

motion control instructions.

Minimum I/O response time = Priority-16 periodic task period +

Primary period (= process data communications cycle)

Slave A

Servo A

IN

Execution command

Process data

communications cycle

= Primary period (t)

Primary

IO

UPG

MC

IO

UPG

MC

IO

UPG

MC

IO

UPG

MC

periodic task

Processing is performed in

the motion control processing

Commands to Servo A are sent via

(MC) section of the next

EtherCAT communications when I/O

primary periodic task.

is refreshed in the next primary period.

Task period (e.g., t × 2)

Task period (e.g., t × 2)

5

Priority-16

UPG

UPG

periodic task

FB

FB

Motion control instructions executed.

Motion control instructions executed.

Note: The above diagram shows only one input and one output.

However, the response time may be as follows depending on the timing of the input from the slave.

Maximum I/O response time = Priority-16 periodic task period +

Primary period (= process data communications cycle) x 2

z Simultaneous Execution of More Than One Axis

If more than one axis is controlled by the programs in the same task, they can be started at the

same time.

Motion control

instructions

Axis A

Motion control

Start commands

are output at the

instructions

Axis B

same time.

Motion control

Axis C

instructions

Additional Information

You can access the values of Axis Variables in the tasks other than those for axis control.

For detailed usage and precautions, refer to the NY-series Industrial Panel PC / Industrial Box

PC Motion Control User's Manual (Cat. No. W559).

5-65

6 Programming

6-1

Overview of Programming

Procedures

This section provides an overview of programming procedures.

The shaded steps in the overall procedure that is shown below are related to programming.

Step 1. Software Design

Step 1-1 Designing I/O and Processing

Step 1-2 Designing Tasks

Step 1-3 Designing Programs

Step 2. Software Setups and Programming

Step 2-1 Slave and Unit Configurations

Step 2-2 Controller Setup

Step 2-3 Programming

6

Step 2-4 Offline Debugging

Step 3. Mounting and Setting Hardware

Step 4. Wiring

Step 5. Checking Operation and Starting Operation on the

Actual System

Refer to 1-4 Overall Operating Procedure for the NY-series Controller for details.

6-3

6 Programming

POU (Program Organization Unit) Design

Reference

z Determine which processes to put into which POUs and design

6-2 POUs (Pro-

the POUs.

gram Organiza-

tion Units)

Note Functions cannot contain function block instructions or function blocks.

z Determine which languages, such as ladder diagrams, inline

6-5 Program-

ST, and ST, to use to create each process.

ming Lan-

guages

Note Inline ST is structured text that is written as an element of a ladder diagram.

Variable Design

Reference

z Design the user-defined variables that you need to create.

6-3-1 Variables

6-3-2 Types of

Variables

z Separate variables into those that you use in more than one

6-3-3 Types of

POU (global variables) and variables that you use in only

User-defined

Variables in

specific POUs (local variables).

Respect to

POUs

z Determine if you need to automatically generate the variable

3-3 I/O Ports

names for the device variables that you use to access slaves

and Device

Variables

and Units or if you need to define them yourself.

z Design the attributes for the variables.

6-3-4 Attributes

of Variables

Variable Name, Data Type, AT Specification, Initial Value, Retain, Constant, and Network

Publish

6-3-5 Data

Types

Decide the data types of your variables (including array specifications, range specifications,

structures, and enumerations).

6-3-6 Deriva-

tive Data Types

z Keep the following precautions in mind when you design

6-3-4 Attributes

variables.

of Variables

6-3-5 Data

•

Retention:

Types

Set the Retain attributes to determine the values that are used for variables when the power

supply is turned ON or when the operating mode changes.

6-3-6 Deriva-

tive Data Types

•

Structures:

When a structure is used for a variable in an instruction, design the program to use the same

structure data type for the input parameter, output parameter, or in-out parameter.

Example: Communications Instructions

•

Array Specifications:

When an array variable is used for the variable for an instruction, design the program to use

an array variable for the input parameter, output parameter, or in-out parameter.

Examples: Shift Instructions, Stack Instructions, and Table Instructions

•

AT Specifications:

Use AT specifications for the variables used for input parameters to certain instructions.

Example: User I/O allocations

•

Network Publishing:

Design the variables for EtherNet/IP tag data links.

6-4

6 Programming

6-2-3

Differences between Programs, Functions, and Function Blocks

Item

POU type

Programs

Function blocks

Functions

Executed upon execu-

Called from a program

Called from a pro-

Execution method

tion of assigned task.

or another function

gram, function, or

block.

function block.

Any instructions

Supported.

Supported.

Not supported.

User-defined functions

Supported.

Supported.

Supported.

Algorithm

User-defined function

Supported.

Supported.

Not supported.

blocks

Executed each period.

Executed each period.

Specify the execution

condition with the EN

Specify the execution

Execution condition

input.

condition with an input

variable.

The hierarchical relationships between programs, functions, and function blocks are shown in the fol-

lowing figure.

Task

Program 1

Program 2

Functions

Function blocks

6

Function blocks

Functions

Functions

6-2-4

Details on Programs

Program Structure

Programs consist of a local variable table and an algorithm.

You can use any function or function block in the algorithm of a program.

Program

Task

Program

Local variable table

Assigned.

Program

Algorithm

FUN

FB

You cannot call programs from other POUs.

6-7

6 Programming

Program Execution Conditions

Programs are executed when the task they are assigned to is executed.

z

Order of Execution

You can set the order of execution of all programs in a task. You specify this order under Task

Settings - Program Assignment Settings in the Sysmac Studio.

z

Related System-defined Variables

All programs have the following system-defined variables in the local variables.

Variable

Data

Meaning

Function

Read/write

name

type

P_First_Run-

First RUN

This flag is TRUE for only one task period after the

BOOL

Read

Mode

Period Flag

operating mode of the CPU Unit is changed from

PROGRAM mode to RUN mode if execution of the

program is in progress.

This flag remains FALSE if execution of the pro-

gram is not in progress.

Use this flag to perform initial processing when the

Controller begins operation.

P_First_Run

First Program

This flag is TRUE for one task period after execu-

BOOL

R

Period Flag

tion of the program starts.*1

Use this flag to perform initial processing when

execution of a program starts.

P_PRGER

Instruction

This flag changes to and remains TRUE when an

BOOL

Read/write

Error Flag

instruction error occurs in the program or in a func-

tion/function block called from the program.

After this flag changes to TRUE, it stays TRUE until

the user program changes it back to FALSE.

P_CY

Carry Flag

This flag is updated by some instructions.

BOOL

Read

*1

To enable or disable the program, use the PrgStart or PrgStop instruction. You can make setting for the Prg-

Start instruction so that it executes the program without changing P_First_Run to TRUE.

6-2-5

Details on Function Blocks

Procedure to Create Function Blocks

A function block consists of a function block definition that is made in advance and instances that are

used in the actual programs. Create function blocks in the following order.

1 Create the function block definition.

Create the algorithm.

2 Placing an Instance of the Function Block Definition in a Program

Call the function block definition from a program or another function block.

You can call the same function block definition from more than one program or function block.

After you place an instance of a function block definition in a program or in another function

block, you can manipulate and execute it as an independent entity.

6-8

6 Programming

Structure of Function Blocks

In a ladder diagram, function blocks are represented as rectangular boxes as shown below. Refer to

Calling Function Blocks from ST on page 6-10 for details about how to express function blocks in ST.

Function blocks consist of the following parts.

•

Function Block in Ladder Diagram:

Instance name

Function block name or instruction name

In-out variable

MyFB_instance

Output variable

TRIG

MyFB

OUT

In

Q

InQ

InQ

SET

RESULT

SetValue

Result

Input parameter

Input variable

Output variable

Output parameter

Algorithm

•

Function Block Settings

When you create an instance of a function block definition, make the following settings.

Settings of a function block instance in a program

Instance name

6

Function block name

Local Variable Table

Input parameters

Output parameters

Input

In-out

Output

variables

variables

variables

Internal variables

Algorithm

• Written as a ladder diagram or in ST.

• You can use any instructions,

user-defined functions, and user-

defined function blocks.

Created in the Function Definition

z Function Block Name or Instruction Name

This is the function block name or instruction name assigned in the function block definition when

the function block is created.

z Instance Name

You give an instance name to a function block instance in a program to enable managing it. You

specify an instance name when you call a function block definition from a program or another func-

tion block.

6-9

6 Programming

z

Algorithm

You can code the algorithm either as a ladder diagram or in ST. You can use any instruction, user-

defined function, or user-defined function block in the algorithm.

z

Local Variable Table

The local variable table is used to define input variables, output variables, in-out variables, internal

variables, and external variables.

Refer to Variable Designations for Function Blocks on page 6-11 for details.

z

Parameters

Input Parameters to Input Variables

An input parameter passes a value to an input variable in a function block when function block exe-

cution begins. An input parameter can be either a variable or a constant.

Output Parameters from Output Variables

An output parameter receives a value from an output variable in a function block when function

block execution is completed. A variable is given as the parameter.

In-Out Parameters Shared between In-Out Variables

The value of the in-out parameter changes within the function block. The same variable is used for

both the input and output.

Additional Information

You can omit input and output parameters. Refer to information on operation when parameters

are omitted in Operation When Parameters Are Omitted on page 6-23 for details.

Calling Function Blocks from ST

The following example shows how to call function blocks from ST.

instance_name(input_variable_1:=input_parameter_1, ... input_variable_N:=input_parameter_N,in-out-

_variable_1:=in-out_parameter_1, ... in-out_variable_N:=in-out_parameter_N,output_variable_1=>out-

put_parameter_1, ... output_variable_N=>output_parameter_N);

You can also omit input variable names and other variable names, and give only the parameters. (If you

do, the parameters must be given in the order that they are given in the function block definition.) Also,

the number of parameters must match the number of input variables and other variables in the function

block definition.

TON_instance

a

TON

c

In

Q

b

d

PT

ET

Function Blocks Expressed in ST:

Instance name

TON_instance(In:=a, PT:=b, Q=>c, ET=>d);

TON_instance(In:=a, PT:=b, Q=>c); (*The ET output is omitted here.*)

TON_instance(a,b,c,d); (*Input and output variables are omitted here.*)

6-10

6 Programming

Refer to Function Block Calls in ST Language Statement on page 6-121 for details.

Variable Designations for Function Blocks

Instance Name

Function block definition name

Value is assigned.

or instruction name

Value is assigned.

Input parameter

Input

Internal

Output

Output parameter

variable

variables

variable

Variable assignment

Variable assignment itself is passed.

itself is passed.

In-out parameter

In-out variable

In-Out variable

In-out parameter

The specifications for variables in function blocks are given below.

Variables

Number

Specification

Input variables

1 to 64

Input variables are used as input arguments within the function block. They can-

not be changed inside the function block.

• When the function block is executed, the input variables are set to the values of

the input parameters.

• You can specify either constants or variables for input parameters.

• Omitting Input Parameters:

Refer to information on operation when parameters are omitted in Operation

When Parameters Are Omitted on page 6-23.

• You can specify to detect when the variable changes to TRUE or changes to

6

FALSE.

• You can access and change the values from outside the function block. Access

these values using the following format: InstanceName.InputVariableName.

Output vari-

1 to 64

Output variables are used as output arguments from the function block.

ables*1

• The output parameters are set to the values of the output variables at the end

of function block execution.

• You cannot specify a constant or a variable with constant attribute for an output

parameter.

• You can omit output parameter connections. If you omit an output parameter,

the value of the output variable is not assigned to any parameter.

• You can access the values of output variables from outside of the function

block. Access these values with the following format: InstanceName.Output-

VariableName. However, you cannot write values directly to an output variable.

In-out variables

0 to 64

In-out variables are used as inputs to and outputs from the function block. They

can be changed inside the function block.

• The value of an in-out parameter is passed to an in-out variable and the value

of the in-out variable is then passed to the in-out parameter.

• You cannot specify a constant or a variable with constant attribute for an in-out

parameter.

• If you change the value of an in-out variable within a function block, the value

of the in-out parameter changes at that time.

• You cannot omit in-out parameters.

Internal vari-

No limit

Internal variables are used for temporary storage within a function block.

ables

• The values of internal variables are retained regardless of whether the function

block is executed.

• Internal variables can have Retain attributes.

• You cannot access the values of internal variables from outside of the function

block.

6-11

6 Programming

Variables

Number

Specification

External vari-

No limit

External variables are used to access global variables.

ables

EN

0

An EN variable cannot be used in a function block. (This applies to both user-

defined function blocks and FB instructions.)

ENO

0 or 1

Generally, this is a BOOL output variable that is set to TRUE for a normal end,

and to FALSE for an error end.

• You can also omit it for some FB instructions.

• Refer to ENO on page 6-20 for details.

*1

At least one BOOL output variable (including ENO) is required when you use function blocks in a ladder dia-

gram.

Refer to 6-3-4 Attributes of Variables for details on setting variable attributes.

Additional Information

If you define an external variable with the same name as a global variable in a function block, it

is defined automatically based on that global variable.

z ENO

• When ENO is FALSE, the previous values of all other output variables are retained.

6-12

6 Programming

Function Block Definitions and Instances

A function block consists of a function block definition that is made in advance and instances that are

then used in the actual programs. All instances of a function block are based on the function block defi-

nition.

A function block definition consists of an algorithm and a local variable table.

z Function Block Instance

When you place an instance of a function block definition in a program or another function block, the

function block definition is treated as a part of that program or function block.

Function block definitions that are called from a program or another function block are called

instances.

Every instance of a function block has an identifier known as an instance name associated with it,

and every instance uses memory.

You can create instances of a function block definition to process different I/O data in the same way.

Program POU

Instance name

FB1_1

Function block definition name

FB1

Variable

Memory area

Memory area

declarations

reserved.

Algorithm

Memory for

instance

6

FB1_1

Memory for

instance

FB1_2

Instance name

FB1_2

Function block definition name

FB1

Variable

declarations

Memory area reserved.

Algorithm

Instances cannot be read from other programs or function blocks. If an instance with the same name

as another instance is placed in a different program or another function block, that instance will

operate as a completely separate instance.

6-13

6 Programming

Array Specifications for Instances

Array specifications can be made for instances. You can indirectly specify an array element number

with a variable to execute multiple instances with one instance name. Furthermore, you can switch

input sources and output destinations and effectively execute multiple instances with a single

instance name if you use an array specification for the input parameter and output parameter and

specify the element numbers with the same variable.

Example:

Not Using an Array to Specify Instances

Using an Array to Specify Instances

timer0

FOR

TON

EN

ENO

IN[0]

OUT[0]

In

Q

UINT#0

Initval

Index

i

PT[0]

PT

ET

UINT#4

Endval

UINT#1

Stepval

timer1

Here, array variables are

timer[i]

TON

used to specify instances of

TON

the function block definition

IN[1]

OUT[1]

In

Q

IN[i]

OUT[i]

TON and all input parameters

In

Q

and output parameters. All of

PT[1]

PT

ET

the element numbers are

PT[i]

PT

ET

incremented to execute five

instances in succession.

timer2

NEXT

EN

ENO

TON

IN[2]

OUT[2]

In

Q

PT[2]

PT

ET

timer3

Variable Table

TON

IN[3]

OUT[3]

Variable name

Data type

In

Q

IN

ARRAY [0..4] OF BOOL

PT[3]

PT

ET

OUT

ARRAY [0..4] OF BOOL

PT

ARRAY [0..4] OF TIME

timer

ARRAY [0..4] OF TON

timer4

i

UINT

TON

IN[4]

OUT[4]

In

Q

PT[4]

PT

ET

6-14

6 Programming

Execution Conditions for Function Blocks

Function blocks do not have an EN input like functions. They are executed each period.

Processes That Require Constant Data Monitoring

Case

Algorithm in FB

ENO

Operations other than ENO

Normal opera-

Executed.

Normal end

TRUE

Output parameters: Values are updated

tion

according to the internal algorithm.

In-out parameters: Values are updated

according to the internal algorithm.

Error end

FALSE

Output parameters: Retained

In-out parameters: Values are updated

according to the internal algorithm.

Inside a mas-

Executed when the state of

User-specified

One of the above, depending on the value

ter control

the power flow input is

of ENO.

region

FALSE.

Refer to 6-5-2 Ladder Diagram Language for details on power flow output and parameter output.

You can specify the edge for an input variable to make the variable TRUE only when the input

parameter changes to TRUE.

Instance

Variable A

FB

A

X

6

Instance X

Specifies detecting a change to TRUE.

You can specify falling edges too.

Instance

Variable A

FB

A

X

Instance X

Specifies detecting a change to FALSE.

6-15

6 Programming

Accessing Variables in a Function Block from Outside the Function

Block

You can access the input and output variables of a function block from outside the function block. Vari-

ables are written as follows:

InstanceName.VariableName

Example: To Access Output Variable B of Function Block Instance FB1_Instance

FB1_Instance.B

You can access the input and output variables for a function block only within the program that contains

the function block. However, you cannot access these variables from within other function block

instances even if they are in the same program. You cannot access them from other programs.

Program P1

FB1_Instance

FB1

Input and Output Variables for FB1

A

B

• Access is possible only from within program P1.

Can be accessed.

• Access is not possible from program P2.

• Access is not possible from within FB2.

FB1_Instance.B

Cannot be

accessed.

FB2_Instance

FB2

C

D

Program P2

Cannot be

accessed.

FB2_Instance.B

The following variables cannot be accessed from external devices. If these variables are accessed, a

building error will occur.

• In-out variables for function blocks

• Input variables for FB instructions for which the default value is not applied if an input parameter is

omitted

6-16

6 Programming

6-2-6

Details on Functions

Structure of Functions

In a ladder diagram, functions are represented as rectangular boxes as shown below. Refer to Express-

ing Functions in ST on page 6-18 for details about how to express functions in ST. A function consists of

the following parts.

Function in Ladder Diagram:

Function name or instruction name

EN input

ENO output

MyFUN

EN

ENO

Return value

Para1

In1

ret_val

Para2

In2

Out1

Output1

Input parameters

Input variables

Output variable

Output parameter

z

Function Name or Instruction Name

This is the function name or instruction name assigned in the function definition when the function is

6

defined.

z

Instance Name

Functions do not have instance names.

z

Algorithm

You can code the algorithm either as a ladder diagram or in ST. You can use function instructions or

user-defined functions in the algorithm of a function. You cannot use any FB instructions or user-

defined function blocks. You also cannot use a differentiated instruction (e.g., R_TRIG or UP).

You cannot use the P_First_RunMode and P_First_Run system-defined variables.

Function

Local variable table

EN

Output parameter

Input parameter

Output

Input

In-out

variable

variable

variable

(return value)

Internal variables

Algorithm

FUN instruction

User-defined

function

6-17

6 Programming

z Local Variable Table

A local variable table defines the input variables, output variables, in-out variables, internal vari-

ables, and external variables.

Refer to Variable Designations for Functions on page 6-19 for details.

z Parameters

Input Parameters to Input Variables

An input parameter passes a value to an input variable in a function when function execution begins.

An input parameter can be either a variable or a constant.

Output Parameters from Output Variables

An output parameter receives a value from an output variable in a function when function execution

is completed. A variable is given as the parameter.

In-Out Parameters Shared between In-Out Variables

The value of the in-out parameter changes within the function. The same variable is used for both

the input and output.

Expressing Functions in ST

The following example shows how to call functions from ST.

return_value:=function_name (input_variable_1:=input_parameter_1, ... input_variable_N:=input_pa-

rameter_N,in-out_variable_1:=in-out_parameter_1, ... in-out_variable_N:=in-out_parameter_N,out-

put_variable_1=>output_parameter_1, ... output_variable_N=>output_parameter_N);

However, you can also omit the return value.

You can also omit input variable names and other variable names, and give only the parameters. (If you

do, the parameters must be given in the order that they are given in the function definition.) Also, the

number of parameters must match the number of input variables and other variables in the function

definition.

Functions Expressed in ST:

MAX

EN

ENO

Para1

In1

Para_MAX

Para2

In2

Function name

Para_MAX := MAX(In1:=Para1, In2:=Para2);

Para_MAX := MAX(Para1, Para2);

(*The input variables are omitted here.*)

Refer to Function Calls on page 6-124 for details.

6-18

6 Programming

Variable Designations for Functions

Function name or instruction name

Value is assigned.

Return value

Return value parameter

Value is assigned.

Value is assigned.

Internal

Input parameter

Input

Output

Output parameter

variables

variable

variable

Variable assignment

Variable assignment

itself is passed.

itself is passed.

In-out parameter

In-out variable

In-out variable

In-out parameter

The specifications for variables in functions are given below.

Variables

Number

Specification

Input variables

0 to 64

Input variables are used as input arguments within the function. They cannot be

changed inside the function.

• When the function is executed, the input variables are set to the values of the

input parameters.

• You can specify either constants or variables for input parameters.

• Omitting Input Parameters:

Refer to information on operation when parameters are omitted in Operation

When Parameters Are Omitted on page 6-23.

• Unlike function blocks, you cannot specify to detect changes to TRUE or

6

FALSE.

• You cannot access the values of input variables from outside of the function.

• Some of the instructions provided by OMRON can have varying numbers of

input variables, but you cannot make a user-created function that has a vary-

ing number of input variables.

Output variables

0 to 64

Output variables are used as output arguments from the function.

• The output parameters are set to the values of the output variables at the end

of function execution.

• You cannot specify a constant or a variable with constant attribute for an out-

put parameter.

• At least one BOOL output variable (including ENO and the return value) is

required.

• You can omit output parameter connections.

If you omit an output parameter, the value of the output variable is not

assigned to any parameter.

• You cannot access the values of output variables from outside of the function.

• The values of the output variables of user-defined functions must always be

set in the algorithms of the functions. If the output variables are not set in the

algorithms of the functions, the values of the output variables are not stable.

In-out variables

0 to 64

In-out variables are used as inputs to and outputs from the function. They can be

changed inside the function.

• In-out parameters (variable designations) are directly passed to or received

from the in-out variables.

• You cannot specify a constant or a variable with constant attribute for an in-out

parameter.

• If you change the value of an in-out variable within a function, the value of the

in-out parameter changes at that time.

• You cannot omit in-out parameters.

• You cannot access the values of in-out variables from outside of the function.

6-19

6 Programming

Variables

Number

Specification

Internal vari-

No limit

Internal variables are used for temporary storage within a function.

ables

• The value is not retained after execution is completed.

• You cannot access the values of internal variables from outside of the function.

External vari-

No limit

External variables access global variables.

ables

EN

1

This is a BOOL input variable used to execute the function.

• The function is executed when EN is TRUE.

• You must have one EN variable. (This applies to both user-defined functions

and FUN instructions).

ENO

0 or 1

Generally, this is a BOOL output variable that is set to TRUE for a normal end,

and to FALSE for an error end.

• You can omit the ENO variable from user-defined functions.

• Refer to ENO on page 6-20 for details.

Return value

1

The return value is the value that is returned to the calling instruction. It rep-

resents the results of the process after the algorithm in the function is executed.

• Each function must have one return value.

• You can specify enumerations of all basic data types. You cannot specify an

array, structure, or union.

• The return values of user-defined functions must always be set in the algo-

rithms of the functions. If return values are not set in the algorithms of the

functions, the return values are not stable.

• Refer to Return Values on page 6-21 for details.

Refer to 6-3-4 Attributes of Variables for details on setting variable attributes.

Additional Information

You can register global variables as external variables in a function variable table to access

global variables. We recommend that you create your functions so that they produce output val-

ues uniquely based on their input parameter values. Algorithms that access global variables and

use them to affect the output values are not recommended. When you check the program on the

Sysmac Studio, a message will appear that says that it is not recommended to use global vari-

ables in functions. Take appropriate measures if necessary.

z ENO

• When ENO is FALSE, the previous values of all other output variables are retained.

6-20

6 Programming

z

Return Values

•

Return values are blank in ladder diagrams.

Case

Ladder diagram notation

ST language notation

Using return values

variable_q:= MyFUN1(vari-

MyFUN1

able_i);

EN

ENO

Variable i

Variable q

IN

Not using a return

MyFUN2(In1:=vari-

value

MyFUN2

able_i1,In2:=variable_i2,

EN

OutEQ=>variable_q1,

OutNE=>variable_q4 );

Variable i1

In1

Variable i2

Variable q1

In2

OutEQ

OutGT

OutGE

Variable q4

OutNE

OutLT

OutLE

6

•

The calling instruction is not required to use the return value in either a ladder diagram or ST.

•

If you set the return value within a function algorithm, set the value to a variable with the same

name as the function.

For example, the return value of a function called MyFUN is MyFUN.

MyFUN

Definition of MyFUN

EN

ENO

IF IN>100

Variable i

Variable q

MyFUN:=100;

IN

ELSE

MyFUN:=IN;

END_IF;

Execution Conditions for Functions

A function is executed when EN is TRUE. The function stops processing when EN changes to FALSE.

Input variables

Algorithm in FUN

ENO

Operations other than ENO

EN = TRUE

Executed.

Normal end

TRUE

Output parameters: Values are updated according to

the internal algorithm.

In-out parameters: Values are updated according to

the internal algorithm.

Error end

FALSE

Output parameters: Values are retained.

In-out parameters: Values are updated according to

the internal algorithm.

EN = FALSE

Not executed.

FALSE

Output parameters and in-out parameters: Values

are retained.

Inside a master

Not executed.

FALSE

Output parameters and in-out parameters: Values

control region

are retained.

6-21

6 Programming

Example:

BOOL variable A

Algorithm within function

in

MyFUN

MyFUN

EN

ENO

P_On

BOOL variable B

in

Function

execution

ENO

You can change ENO with the

algorithm in the function.

BOOL variable A

BOOL variable B

6-2-7

Operation That Applies to Both Functions and Function Blocks

Using or Omitting EN and ENO

The following table shows when you can use and when you can omit EN and ENO in functions and

function blocks.

POU

EN

ENO

FB

User-defined

Cannot be used.

Can be used or omitted.

functions

A building error occurs if you try to define

You define ENO as an output variable in

EN in the variable table from the Sysmac

the Sysmac Studio.

Studio.

Instruction

All FB instructions do not use EN.

Some instructions use ENO, and others

do not.

FUN

User-defined

Required.

Can be used or omitted.

functions

When you create a function, the Sysmac

You define ENO as an output variable in

Studio automatically adds EN to the vari-

the Sysmac Studio.

able table by default.

Instruction

All FUN instructions use EN.

Some instructions use ENO, and others

do not.

6-22

6 Programming

Operation When Parameters Are Omitted

You can omit both input and output parameters.

Operation when omitted

Parameters omitted in

FB

FUN

• When the first time the instance is executed, the

• EN is operated when its

initial value is used.

value is TRUE.

Input parameters to input

• Thereafter, the function block is executed with the

• For other input parame-

variables

previous value (if the input variable is omitted, the

ters, the initial value is

initial value is always used).

used for operation.

Can be omitted.

You can omit the output

Output parameters from

parameter. If it is omitted,

You can access the results of the operation outside

output variables

there is no way to retrieve

of the instruction by using InstanceName.OutputVari-

the result of the operation.

ableName.*

In-out parameters to/from

Cannot be omitted.

Cannot be omitted.

in-out variables

* You can access the input and output variables of a function block from outside of the function block (but only

within the same program) with InstanceName.VariableName. However, you cannot access the input and output

variables of a function from outside the function.

FBinstance

FB

Omitted.

Done

6

FBinstance.Done

Can be specified by using InstanceName.Done.

Operation for Parameter Errors

The following operation occurs when there is an error in an input parameter, output parameter, or in-out

parameter.

z Errors in Input Parameters

If an error is detected in an input parameter, the function or function block is not executed and ENO

is FALSE. The power flow output is also FALSE, but all other values are retained.

Example:

Function

EN

ENO

FALSE

x[i]

IN1

x[10]

IN2

OUT2

abc Retained.

Variable Table

Variable name

Array

Data type

Example when variable i is outside the

x

[ 1 .. 10 ]

INT

range of the elements in array variable x

6-23

6 Programming

z

Errors in Output Parameters

If an error is detected in an output parameter, all values after that parameter are not output but their

values are retained.

Example:

Function

EN

ENO

Example when variable i is outside the

range of the elements in array variable x

IN1

OUT1

x[9]

IN2

OUT2

x[i]

OUT3

x[10] Retained.

Not output.

z

Errors in In-Out Parameters

If an error is detected in an in-out parameter, the function or function block is not executed and ENO

is FALSE. The power flow output is also FALSE, but all other values are retained.

Function

OFF

EN

ENO

x[i]

x[i]

INOUT--

--INOUT

X xyz Retained.

Example when variable i is outside the

range of the elements in array variable x

Recursive Calling

The following recursive calls are not allowed for functions or function blocks. They will result in an error

when you build the user program on the Sysmac Studio.

• A function or function block cannot call itself.

• A called function or function block cannot call the calling parent.

6-2-8

POU Restrictions

This section describes the restrictions in the creation of POUs.

Names

Refer to 6-3-12 Restrictions on Variable Names and Other Program-related Names for restrictions on

POU names and function block instance names.

Passing Multiple Arguments

If you need to pass multiple arguments to a function or function block, use an array specification or

structure to pass the required data.

This will make your program simpler. However, be aware that if you use an in-out variable, the data

passed to the function block or function as a parameter is written and the original data is not retained.

6-24

6 Programming

Additional Information

Specifying an Array Variable or Structure Variable as a Parameter

You can also specify an array variable or a structure variable as an input or output parameter.

However, it will take longer to pass and receive data for these data types in comparison to a vari-

able with a basic data type (depending on the size). Therefore, when handling array variables or

structure variables in a function block, we recommend that you design them in such a way that

these variables are passed to and received from in-out variables.

Example 1: Specifying an Array

Program Variable Table

Variable name

Data type

x

ARRAY[0..199] OF INT

FB

Do not assign INT variable x [0..199] to the function block input variable

x

IN1

OUT1

IN1 (Data type of the IN1 input variable in the function block:

ARRAY[0..199] OF INT).

FB

Instead, assign INT variable x [0..199] to the INOUT in-out variable of

the function block. (Data type of INOUT in-out variable in the function

x

INOUT

INOUT

block: ARRAY[0..199] OF INT)

6

Example 2: Specifying a Structure Variable

Program Variable Table

Variable name

Data type

x

MyStructure

FB

Do not assign MyStructure variable x to the IN1 input

x

IN1

OUT1

variable of the function block (Data type of IN1 input

variable of the function block: MyStructure).

FB

Instead, assign MyStructure variable x to the INOUT in-out

x

INOUT

INOUT

variable of the function block. (Data type of INOUT in-out

variable of the function block: MyStructure)

6-25

6 Programming

Nesting Levels

Calling another function or function block from a function or function block that was called from a pro-

gram is called nesting. The limits that are given in the following table apply to the POUs that you can

call from a user-defined function or function block and the number of nesting levels. A building error will

occur if these limits are exceeded.

POU

Called POUs

Nesting depth

Function blocks

Functions and function blocks

8 levels max.

Functions

Functions

16 levels max.

Example 1: From a program, you can call function blocks to a depth of 8 levels. You can then call func-

tions to a depth of 16 levels.

Program

FB1

FB7

FB8

FUN15

FB1

FB2

FB8

FUN9

FUN16

Level 1

Level 2

Level 8

Level 9

Level 16

You cannot call a function

You cannot call a function

block at level 9.

at level 17.

Example 2: From a program, you can call functions to a depth of 16 levels.

Program

FUN1

FUN15

FUN1

FUN2

FUN16

Level 1

Level 2

Level 16

You cannot call a

function at level 17.

6-26

6 Programming

6-3

Variables

In the NY-series System, variables are used to exchange I/O information with external devices, to per-

form data calculations, and to perform other processes. This section describes variable designations in

detail.

Refer to the Sysmac Studio Version 1 Operation Manual (Cat. No. W504) for details on setting vari-

ables with the Sysmac Studio.

6-3-1

Variables

Variables store I/O data for exchange with external devices or temporary data that is used for internal

POU processing. In other words, a variable is a container for data with a name, data type, and other

attributes.

You do not need to assign a memory address to a variable. The NY-series Controller automatically allo-

cates memory addresses in the memory area for variables.

6-3-2

Types of Variables

Variables are broadly classified into the following three types.

z User-defined Variables

The user defines all of the attributes of a user-defined variable. The rest of this section describes

user-defined variables.

6

z Semi-user-defined Variables

These variables are used to access specific devices and data. There are two types of semi-user-

defined variables: device variables and cam data variables. Refer to 2-3-1 Types of Variables and 3-

3-1 I/O Ports for details on device variables.

z System-defined Variables

System-defined variables are provided in advance in an NY-series Controller. The names and all

attributes are defined by the system. They have specific functions. System-defined variables are

supplied for each function module. Refer to A-3 System-defined Variables for details.

Refer to 2-3-1 Types of Variables for details on the different types of variables.

6-3-3

Types of User-defined Variables in Respect to POUs

There are six types of user-defined variables as defined according to their function in a POU.

POU type

Type of user-defined variable

Programs

FB

FUN

Internal variables

Supported.

Supported.

Supported.

Input variables

Not supported.

Supported.

Supported.

Local variables

Output variables

Not supported.

Supported.

Supported.

In-out variables

Not supported.

Supported.

Supported.

Global variables

Supported (see note).

Supported (see note).

Supported (see note).

External variables

Supported.

Supported.

Supported.

* You can define global variables as external variables to access the global variables through the external vari-

ables.

6-27

6 Programming

Local Variables

Local variables can be read and written only in the POU (program, function, or function block) in which

it is defined. Local variables are the same as internal variables if the POU is a program. If the POU is a

function block or a function, “local variable” is a collective term for internal variables, input variables,

output variables, in-out variables, and external variables.

z Internal Variables

A local variable can be used only within one POU. An internal variable is declared in the local vari-

able table for the POU. You cannot access the values of internal variables from outside of the POU.

You can declare internal variables with the same names in different POUs. Each of those variables

is assigned to a different memory area.

z Input Variables

When a POU is called, the input variables are assigned to the values of the input parameters from

the calling POU. An input variable is declared in the local variable table of the POU.

z Output Variables

Before processing a POU is completed, the output parameters returned to the calling POU are

assigned to the output variables. An output variable is declared in the local variable table of the

POU.

z In-Out Variables

When a POU is called, the in-out variables are assigned to the in-out parameters themselves (vari-

able designations) from the calling POU. If you change the value of an in-out variable within a POU,

the value of the in-out parameter changes at that time. An in-out variable is declared in the local vari-

able table of the POU.

z External Variables

External variables are used to access data outside of a POU. You can access global variables from

POUs.

Global Variables

A global variable is declared in the global variable table.

Device variables that are automatically generated from the Unit configuration and slave configuration

and axis/axes group variables that are generated from the Axis Setting Table are automatically regis-

tered as global variables.

6-3-4

Attributes of Variables

You can set the following attributes for variables.

Variable Attributes According to Variable Type

z Attributes of Variables

Attribute

Description

Specification

Default

The variable name is used to identify the

Variable Name

variable.

The data type defines the format of the

BOOL

Data Type

data that is stored in the variable.

If you want to handle an I/O port for an NX

• Not specified.

Not specified.

AT Specification

Unit or an EtherCAT slave as a variable,

• Specify.

specify the address to assign to that variable.

6-28

6 Programming

Attribute

Description

Specification

Default

Specify whether to retain the value of the

• Retain: Value specified

Non-retain: Reset

variable in the following cases.

on the left is retained.^*1

to initial value

• When power is turned ON after a

• Non-retain: Changes to

power interruption

initial value.

Retain

• When the CPU Unit changes to RUN

mode

• When a major fault level Controller

error has occurred.

You can select to set or not set an initial

Initial Value

Depends on the

value.

data type. (Refer to

• Yes

the section on initial

Initial value setting: Specify the value of

• None

values.)

the variable in the following cases and

do not specify the Retain attribute.

Initial Value

• When power turned ON

• When operating mode changes

• When a major fault level Controller

error occurs

If the initial value is not set, the value is

not retained.

If you set the Constant attribute, you can

Specify making the value

set the initial value of the variable when it

a constant or not a con-

Constant

is downloaded, but you cannot overwrite

stant.

the value afterwards.

This attribute allows you to use CIP com-

• Do not publish

Do not publish

munications and data links to read/write

• Publish Only

Network Publish

variables from outside of the Controller.

• Input

• Output

6

An Edge attribute allows you to detect

• None

None

when the input parameter of a function

• Change to TRUE

Edge

block changes to TRUE or changes to

• Change to FALSE

FALSE. This can be used only on BOOL

input variables.

*1

An AT specification is retained in a non-volatile memory if a UPS is connected to the Industrial PC and the

Industrial PC is normally shut down.

Additional Information

Exclusive Control between Tasks

You can restrict writing to global variables to a single task to prevent changes to the values of

global variables during processing. Specify this as a task setting, not as a variable attribute.

6-29

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