Overview of EXTV parameters
The overview of External Variable parameters is sorted into a 4-column table.
- Column 1 contains the unambiguous identifier of the start-up parameter called the “ID” which consists of the prefix “P-EXTV” and a unique 5-digit number, 
 e.g. P-EXTV-00001.
- Column 2 represents the data structure which defines the parameter, 
 e.g. var[i]
 The structure is a categorisation aid and is described in the following section. If an entry is missing in ‘structure’, this is not an error. The parameter in column 3 is then only valid on its own.
- Column 3 contains the “parameter” with its exact name, 
 e.g. name
 The important thing is that “structure”+”parameter” always belong together and must be configured in exactly the same way in the External Variables list,
 e.g. var[i].name
- Column 4 contains the “functionality” in a summarised term/short description, 
 e.g. name of external variable.
| ID | Structure | Parameter | Functionality/short description | 
|---|---|---|---|
| var[i]. | name | Name of the External Variable | |
| var[i]. | byte_offset | Position of the External Variable in the memory | |
| var[i]. | type | Variable type | |
| var[i]. | scope | Validity of the variable | |
| var[i]. | synchronisation | Synchronisation type of the variable | |
| var[i]. | access_rights | Access rights of the variable | |
| var[i]. | array_elements | Number of elements in an array of structure elements. | |
| var[i]. | size | Size of the variable | |
| var[i]. | create_hmi_interface | Enabling access by HMI | |
| 
 | number_used_variables | Number of configured external variables | |
| 
 | check_overlapping_variables | Plausibility check of the memory layout | |
| 
 | auto_memory_mode | automatic memory layout | |
| 
 | init | Initialisation with default values | |
| struct[i]. | name | Name of the variable type | |
| struct[i].element[j]. | name | Name of the structure element | |
| struct[i].element[j]. | type | Type of the structure element | |
| struct[i].element[j]. | synchronisation | Synchronisation type of the structure element | |
| struct[i].element[j]. | access_rights | Access right of the structure element | |
| struct[i].element[j]. | array_elements | Array size of a structure element | |
| struct[i].element[j]. | size | Size of a structure element of type VSTRING | |
| 
 | use_extended_string_var | Number of characters of a string variable | |
| var[i]. | suppress_export | Suppress variable export to the PLC description | |
| var[i]. | start | Variables with overlapping memory area |