This property - together with the start address - is used to determine the address range of the PLC card. The data length indicates the number of bits up to the next free address on the next PLC card. Enter the number of bits for the inputs of the PLC card, for example "8", here. Note that there are PLC cards, for example technology modules, which are only assigned to a few inputs / outputs, but still require a larger address range. Always enter the maximum required size for the address range of the inputs here.

Reference

Placement3DPropertyList Class
Placement3DPropertyList Members