Hello Agomirr

The IO field itselfe cannot do the usecase. you can only show all signs or no signs (and then you cannot input or show negative values).

But you can work with a workaround. Use a Textfield that looks like the IO field.

here use a VB Script at the textproperty and use the tag itselfe for trigger. Then return the value of the Tag. -> the result is that the static text field shows  only in case of the negative value the sign.

To input values you have to use a dialoge. Open a small popup if you click on the Textfield to open a input field that lays over the text field or a also a input window. close or hide if the inputvalues changes (in property topics events)

Its not that simple as just using an object that does what you want but should bring you closer to your usecase

Bye Murof