Руководство - руководство по программированию в среде U90 Ladder (англ.язык)
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3. Select the desired Address.
4. The element appears with the selected Address and Symbol.
Changing an Operand type
To change an Operand type:
1. Double click on the element's Operand.
2. The Operand and Address dialog box opens.
3. Select the new Operand type.
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4. Enter the new Operand Address and symbol.
5. Click OK. The element appears on the net with the new Operand, Address and symbol.
Operand Locations List
To get a list of Operand locations:
If you already have one location where you know the Operand exists, you can select the Operand and then open
the Find dialog box. A list of all locations of the selected Operand will appear.
1. Click on the Find icon in the Standard toolbar.
2. The Find function opens.
3. Select the name and address of the operand you wish to find.
4. Click the Find button shown below; a list appears showing every time that operand is used in the project.
5. Select the name and address of the operand you wish to replace as shown below.
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6. Select the location of the operand or description you wish to replace by clicking it within the list.
7. Replace operands or their descriptions by clicking the buttons shown below.
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Finding an Operand by symbol
To find an Operand by its symbol when placing an element on a net:
1. Click in the Symbol Search box in the Select Operand and Address dialog box.
2. The Symbol Search dialog box opens.
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3. Begin entering the Symbol name for which you are searching. The list will become more specific the
more letters you enter.
4. Select the desired Operand from the Symbol Search list.
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5. Click OK. The selected element appears on the net with the desired Operand and Address.
Restoring System Symbols
To restore System Symbol values:
Keep in mind that there are SBs and SIs reserved for use by the system, such as SB 4 Divide by Zero or SI 4
Divide Remainder. Those SBs and SIs cannot be written into. If you accidentally write into them, you can
recover their symbols.
Note that SBs and SIs are for system
use. Even those currently 'blank' may be assigned a function in a later
controller model. Writing into System Bits and System Integers is solely at the discretion of the programmer and
the programmer is solely responsible for any problems that may arise as a result.
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Operands in use
To check what Operands are being used in a project:
1. Open the Window Menu on the Main menu bar.
2. Select the Operand type you wish to check.
3. The Operand List window opens. The Operands in use are marked with a check mark in the In Use box.
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Deleted Unreferenced Operands
To help manage your project, you can delete unreferenced operands. The utility searches through the entire
application, including Hardware Configuration, SMS, and PID.
Note •
If an operand has been assigned a Power-up value, it is a referenced operand and will not appear
in this list.
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Operand Values:
The integer value range is 2
16_
1: that is +32767 to -32768.
Keep this integer range in mind when creating function blocks.
For example: MI 75 + #50 = MI 76
If MI 75 goes beyond 32626, the integer value returned in MI 76 will be a negative number!
Functions
Functions
The following types of Function Blocks can be used in your program:
Compare Functions
Logic Functions
Math Functions
Store functions
Clock Functions
Loops: Jump to Label
Special Functions: without Ladder elements
VisiLogic contains special functions that are not represented by Ladder Elements. You can perform these
functions by storing values into the System Integers listed here.
To see a list of functions, check the Special Functions list.
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Compare Functions
A compare function represents a data manipulation instruction. U90 Ladder uses function blocks to operate
compare functions. Each function block takes 2 inputs (MI, SI or a constant integer) and manipulates them
according to the function block instruction.
If the function block instructions are true (logic 1): power flows through the block.
If the function block instructions are false (logic 0): power does not flow through the block.
There are 6 types of Compare Functions:
Greater Than
Greater Than or Equal To
Equal To
Not Equal To
Less Than or Equal To
Less Than
Equal
The Equal function block evaluates input A to see if its constant integer value is equal to input B.
If input A is equal to input B: power will flow through the function block.
If input A is not equal to input B: power will not flow through the function block.
Input Operands A & B must be integer values: MI, SI or # constant integer value.
According to the above example:
If MI 1 is equal to MI 3; then MB 55 will go to logic "1" (ON).
If MI 1 is not equal to MI 3; then MB 55 will go to logic "0" (OFF).
Greater or Equal
The Greater Than or Equal function block evaluates input A to see if its integer value is greater than or equal to
input B.
If input A is greater than or equal to input B: power will flow through the function block.
If input A is not greater than or not equal to input B: power will not flow through the function block.
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According to the above example:
If MI 1 value is greater or equal to constant integer 35; then MB 50 will go to logic "1" (ON).
If MI 1 value is not greater or equal to constant integer 35; then MB 50 will go to logic "0"
(OFF).
Greater Than
The Greater Than function block evaluates input A to see if its current value is greater than input B.
If input A is greater than input B: power will flow through the function block.
If input A is not greater than input B: power will not flow through the function block.
According to the above example:
If MI 1 value is greater than 35; then MB 50 will go to logic "1" (ON).
If MI 1 not greater than 35; MB 50 will go to logic "0".
Care must be taken when using greater and less than function blocks. Do not create a program with instructions
for Greater Than and Less Than but without an instruction block for how to proceed in a situation where input A
equals input B.
Less or Equal
The Less Than or Equal To function block evaluates input A to see if its current value is less than or equal to
input B.
If input A is less than or equal to input B: power will flow through the function block.
If input A is not less than or equal to input B: power will not flow through the function block.