The editors of ST, LD, and FBD maintain the indirect references. An indirect reference lets you to take care of the value of variable to be paid to an order the operand as an pointer to the other data, before it is as actual data. The indirect references are from time to time presented to as the pointers of relation. The indirect references can be made the most of only as below:
• Utilized with the CPU of PACSystems and CPU of Series 90-70.
• It can be utilized n the FBD, LD, and ST editors.
• The indirect references is supported on the instructions. Such as, for PACSystems
• The indirect reference is indexing for the value to %W is a 32-bit DWORD.
• The indirect references can not be utilized to take in hand bits in the memory of 16-bit.
• The indirect references are not supported on the variables of I/O or the variables of symbolic. It is Possible Uses.
• The indirect reference is to carry out the similar operation to a lot of registers.
• The indirect reference is to prevent the repetitious of logic within the program of application.
• The indirect reference in the loop conditions where every register is increased by a value specified or by a constant until a maximum value is achieved.
To allocate an indirect reference
• Write the symbol of @, and followed by an address of valid reference or variable name where a variable operand is projected. The editor of FBD, LD, or ST exchanges an address of reference to a name of variable or the editor replaces with the variable name that already mapped to the address.
• The actual name of variable does not include the symbol of @. The symbol of @, when utilized at the initiate of an address of reference or name of variable, only specifies that the address or variable have to be delighted as an indirect reference.
• The symbol of @ can be thinking of as an user with the precedence of lowest. In other hands, MyArray[2,5] turns out to be an address of reference that is utilized for the indirect reference. Another method to reflect of this is @(MyArray[2,5]) as opposite to (@MyArray)[2,5].
• @R0001 is a name of variable made automatically from an address
• @MyArray[2, 5] is an array reference
• @$MainSwitch is a variable of universal
• @MyTimer.PV is a structure element
GE Fanuc PLC
GE Fanuc PLC