GE 90-30/20/Micro manual Function Block Parameters, Mul

2

Function Block Parameters

Each line entering the left side of a function block represents an input for that function. There are two forms of input that can be passed into a function block: constants and references. A constant is an explicit value. A reference is the address of a value.

In the following example, input parameter I1 comes into the ADD function block as a constant, and input parameter I2 comes in as a reference.

		_____
%I0001				%Q0001
—— ———		ADD_———————————————————————————————————————————˝———————————————( )—
		INT
CONST —I1			Q—%R0002
+00010
%R0001 —I2
	_____

Each line exiting the right side of the function block represents an output. There is only one form of output from a function block or reference. Outputs can never be written to constants.

Where the question marks appear on the left of a function block, you will enter either the data itself, a reference location where the data is found, or a variable representing the reference location where the data is found. Where question marks appear on the right of a function block, you will usually enter a reference location for data to be output by the function block or a variable that represents the reference location for data to be output by the function block.

		_____
	—	MUL_—
		INT	—
—————————			—————————
???????—I1			Q—???????
			—————————
???????—I2				————— This is the output parameter (Q)
—————————				for the function block.
	_____

_____ These are the input parameters (I1 and I2)

for the function block.

Most function blocks do not change input data; instead, they place the result of the operation in an output reference.

2-28 Series 90-30/20/Micro Programmable Controllers Reference Manual– September 1998 GFK-0467K