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The Special
Function Variables
SIMATIC VPU200/565 Programming Manual
Variable types are used in special function programming. Each type is an
abbreviation for a parameter or variable in the 560/65 P/C. The variable
must be followed by an identifying number for the particular parameter or
variable indicated by the abbreviation. For example, "LERR" is the
designation for loop errors. An identifying number must be added to the
name to create a useable, correct variable. For example, "LERR34" would be
a correctly identified variable.
Most variables may be either real or integer (although some, as noted in the
chart which is included in this section, must be either one or the other.) A
real variable is distinguished from an integer by placing a period (".") at the
end of the variable name. For example, "AADB110." is a real variable, while
"AADB110" is an integer variable.
Variables used in IF, IMATH, and MATH statements are allowed to have
one subscript. The subscript may be either an integer or an expression
which evaluates to an integer. (The expression may contain real variables
for IF and MATH statements; for IMATH statements, the variables must be
integers.) Lastly, the subscript is separated from the variable by
parentheses.
The effect of the subscript is to cause the address of the variable to be offset
by the amount of the subscript. For example, "V100.(WY256)" could be a
variable used in a MATH statement. The effect of the subscript would be to
change the address in V-memory: If WY256 is equal to 4, the variable would
be interpreted as "V103."; if 9, the variable would be "V108.". In other
words, the address in V memory is offset from V100. by the value of WY256.
When the subscripts are numbers rather than memory locations, they are
interpreted as shown in the following examples.
Reals
V100.(1)=V100.
V100.(2)=V101.
V100.(3)=V102.
V100.(4)=V103.
The following table gives the variables used in special function
programming. The chart also shows what the abbreviation means, whether
the variable may be real or integer (or both), and information which may
help when using the variable in a statement. The symbol "ID#" which
appears in the chart stands for identifying number and is followed by the
range allowed for the identifying number. (If the symbol does not appear for
a particular entry, the range for the variable is determined by the memory
configuration.)
Integers
V100(1)=V100
V100(2)=V101
V100(3)=V102
V100(4)=V103
Programming Special Functions
6-15
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