If the register name cannot be found in the list of variables, it can be added using its address.
In ethernet I/O scanner, when adding new variable, select the type of variable as "logical address". Then enable searching in "internal addresses". Choose the logical address you want to add and start searching.
The variable should appear in the list, so you can add it. See attached picture.
When it comes to PUC variable (not available in ATV630) , bear in mind that in latest fw of ATV930 and ATV340 there has been added new PUCD variable that carries the same type of information as PUC (counting pulses from encoder), but its range is 32-bit value.
PUC at address is 5611 is 16-bit value
PUCD at address 5668 is 32-bit value