Technical data

Table Of Contents
Glossary
System Software for S7-300/400 System and Standard Functions - Volume 2/2
Glossary-16
A5E00739858-01
User Program
The user program contains all the statements and declarations and the data for
signal processing with which a system or process can be controlled. It is assigned
to a programmable module (module, programmable) and can be structured in
smaller units known as blocks.
User Program Error
Errors which may occur during the processing of the user program in a
SIMATIC S7 PLC (in contrast to process errors). The operating system handles
errors using error OBs (priority class system), the status word and output
parameters from system functions.
Variable
A variable defines a data with variable contents that can be used in the STEP 7
user program. A variable consists of an address (for example, M 3.1) and a data
type (for example, BOOL) and is represented by a symbol (for example,
MOTOR_ON).
Variable Declaration
The variable declaration incorporates the entry of a symbolic name, a data type
and possibly a default value, address and comment.