Definition of external variables

Designator

Value range

Default

Significance

anzahl_belegt

[0; MAX_UNS16]

0

If var[i].* is assigned without gap, here the index of the variable defined last +1 is entered (ilast+1).

If var[i].* is assigned with gaps, here the highest index of the defined variables +1 is entered (imax+1).

var[i].*

i:= [0; 214]

Data records for the definition of variables.

name

ASCII-String

 

The variable is identified on the basis of the name. The name is used to compose an overall name for the NC-channel and the GUI (e.g. V.E.<name>). The name consists of maximum 20 characters.

Upper case letters and lower case letters are differentiated.

byte_offset

[0; MAX_SGN32]

-1

This parameter defines the position in the memory at which the variable is saved.

The indication of this parameter is optional. All variables withbyte_offset of –1 are entered in an unbroken order (start with offset 0) in the V.E.memory.

type

[BOOLEAN,
SGN08, UNS08, SGN16, UNS16, SGN32; UNS32, REAL64, STRING, user defined]

UNS32

The type indicates the data type of the variable. Besides elementary data types (SGN08, ..., REAL64), and data type STRING here also an user defined variable type (see chapter) can be defined.

scope

[GLOBAL; CHANNEL]

CHANNEL

In the case of the scope of validity, a distinction is made between a channel-specific scope and a cross-channel, global scope.

synchronisation

[TRUE, FALSE]

TRUE

Write/read access is normally performed synchronously with processing. In individual cases, this implicit synchronisation may be suppressed (see Chapter 3.1.1).

If the variable is a variable structure, the synchronisation type is inherited to all subordinated structure elements. Additional with the type definition (see chapter) the synchronisation type can be set individually for each structure element.

access_rights

[READ_WRITE, READ_ONLY, WRITE_ONLY]

READ_WRITE

Write/read access to the variables is possible by default, and this access can be restricted by access protection.

If the variable is a variable structure, the access right is inherited to all subordinated structure elements. Additional with the type definition (see chapter) the access right can be set individually for each structure element.

array_elements

[0; MAX_UNS16]

0

If the variable is not structured as an array, the array size must be specified as 0. Otherwise, the total size of the array is defined at this point.

size

[0; MAX_UNS32]

Derived from data type (see Table 2-1)

The indication of the variable size is optional. If it is not indicated, the size is derived from the variable type. The indication of the variable size only is necessary, ifadditional alignment bytes have to be considered. With arrays the parameter indicates the size of the single elements.

create_hmi_interface

[TRUE, FALSE]

FALSE

In case the flag is TRUE, for each variable in addition the access by a corresponding communication object via the user interface can be enabled. For variables with user defined data type this parameter has no effect.