Technical data

Appendix
27.3 Data Types and Parameter Types
Programming with STEP 7
600 Manual, 05/2010, A5E02789666-01
27.3.3.3 Using Complex Data Types
You can create new data types by combining the elementary and complex data types to create the
following complex data types:
• Array (data type ARRAY): an array combines a group of one data type to form a single unit.
• Structure (data type STRUCT): a structure combines different data types to form a single unit.
• Character string (data type STRING): a character string defines a one-dimensional array with a
maximum of 254 characters (data type CHAR). A character string can only be transferred as a
unit. The length of the character string must match the formal and actual parameter of the
block.
• Date and time (data type DATE_AND_TIME): the date and time data type stores the year,
month, day, hours, minutes, seconds, milliseconds, and day of the week.
The following figure shows how arrays and structures can structure data types in one area and
save information. You define an array or a structure either in a DB or in the variable declaration of
an FB, OB, or FC.