Like using variable groups proper selection of index and subindex can help to keep the
GUI definition maintainable. See dedicated section of variable concept for
recommendations on index and subindex.
Warning: Although one can change index and subindex here they render all references
to this variable useless. I.e. if you have to modify index or subindex after assigning the
variable anywhere (DDO, mapping, action ...) you have to re-visit all these assignments
and assign them again.
SubIndex
Subindex is directly tied to index - every subindex can only occur for one variable per
index.
If you set subindex to 0 then this is the only variable for this index. If you skip subindex 0
you can define up to 254 (0x01 ... 0xFE) subindices per variable thus using the index like
a group definition containing subindices that also belong together logically.
See property "index" above and dedicated section of variable concept for
recommendations on index and subindex.
Owner
Every variable needs an owner and only the owner is allowed to actually change the
value of the variable. Here you can assign either one of the predefined or your self
defined owners.
There is an extra page for creation and maintenance of owners . Recommendations
about owner assignment can be found on general variable page .
Description
This property exists for documentation and maintenance - please take the time to
provide a short comment about the purpose and specific use of this variable.
Like that this property can make it easier to understand the GUI definition - especially for
persons not involved in its development, e.g. maintainers or our support team.
Data Type
For CANopen this is how the variable will be maintained in object dictionary, mapped to
PDOs and published in EDS. For other protocols or internal use you should choose a
format covering the variable's purpose while avoiding to waste space in CAN
messages.
Internally all numeric variables are stored as 32 bit anyways - so if in doubt and not using
CANopen "INTEGER32" or "UNSIGNED32" should work for most applications. When
adding the variable to mappings you may have to reduce its mapped size because
default is to reserve the amount of bits defined here.
Custom data type creation is explained at the top of this page .
Maximum Length (in bits/bytes)
For numeric data types the length in bits is part of the data type and just shown here - i.e.
this property is not editable for numeric types.
For strings this property defines the maximum length in bytes. This length is only
enforced for user input in the program as well as on the device. Otherwise longer strings
can be written to and read from string variables.
Please note that the display internally uses UTF-8 encoding which uses up to four bytes
for special characters e.g. used in Russian or Asian language. So if you want the string
to contain such characters you should make sure there is enough room. If you stick to
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