GFK-0467K Chapter 2 System Operation 2-27
2
For a coil, the reference represents a location in memory that is controlled by the flow of power
into the coil. In this example, if power flows into the left side of the coil, reference %Q0004 is
turned ON.
%Q0004
–( )–
The programming software and the Hand-Held Programmer both have a coil check function that
checks for multiple uses of %Q or %M references with relay coils or outputs on functions.
Format of Program Function Blocks Some functions are very simple, like the MCR function, which is shown with the abbreviated
name of the function within brackets:
–[ MCR ]–
Other functions are more complex. They may have several places where you will enter
information to be used by the function.
The generic function block illustrated below is multiplication (MUL); parameters vary with the
type of function block. Its parts are typical of many program functions. The upper part of the
function block shows the name of the function. It may also show a data type; in this case, signed
integer.
_________________
| _____ | This is the function block name (MUL).
| | | |
| | MUL |— |
| | | |
—————|—————|—————
???????—|I1 Q|—???????
| |
| |
???????—|I2 |
|_____|
_________________
| _____ | This is the function block name (MUL)
| | | | and data type (INT). INT (signed integer)
| | MUL_|— | represents the type and size of data to be
| | INT | | acted on.
—————|—————|—————
???????—|I1 Q|—???????
| |
| |
???????—|I2 |
|_____|
Many program functions allow you to select the data type for the function after selecting the
function. For example, the data type for the MUL function could be changed to double precision
signed integer. Additional information on data types is provided earlier in this chapter.