but I need it with something like 4-8 Characters. Any solutions?
Use a I16 for 4 characters, or a I32 for 8 characters.
it seems the XY graph internally works with I64 values for the X axis…
Maybe you should aks the NI support?
I guess it's a problem of the XY graph. I don't think the behaviour is caused by your "personal configuration"…
A hexadecimal format does not contain a symbol for sign and graph axes cannot have a custom format (e.g. a string containing the sign (+/-) and the absolute value formatted in hex).
Unfortunately, this idea is not implemented, so please vote for it. 😄