Is it possible to fill the register adresses with reals or can it only be filled with Integers?
As far as I know only integers are possible.
If you want floating values simply multiply your number before setting the register and divide by the same factor in the robot program after reading the register.
EDIT:
This is only applicable to Modbus Registers. Other Registers such as RTDE have other data types available.
There are also already dedicated float registers, at least in the ethernetIP mappings.
There are boolean registers, integer registers and float registers for access using the appropriate script commands.
16.1.25. read_input_boolean_register(address)
16.1.26. read_input_float_register(address)
16.1.27. read_input_integer_register(address)
16.1.28. read_output_boolean_register(address)
16.1.29. read_output_float_register(address)
16.1.30. read_output_integer_register(address)
16.1.58. write_output_boolean_register(address, value)
16.1.59. write_output_float_register(address, value)
16.1.60. write_output_integer_register(address, value)
There is much more information about these api’s in the script manual about usage as well as register ranges and which part of the range is accessible to PLC’s and which is reserved for RTDE clients. The robot can read and write to all of the register range
If you are dealing with modbus then those registers are only integer registers or boolean coils.