Hi,
If amount is negative then should not be posted and if it's positive then should be posted. I don't think so it's a correct . Since after all in the FI balance sheet debit side should be matched with credit side. If you are updating RT table based upon the clause of negative amount then you have to reconsider the other calculation Part. Like Gross amount, Tax calculation etc.
So before proceed to RT or at the time of WT amount generation you have to consider this clause if this wage type amount is generating negative then it should be zero immediately to further process to next line of the Payroll schema.
Not tell me one thing when this wage type is generating, in which part of the schema is generating... These are those thing valuable to go and design the correct process for payroll run as well as posting.
Regards,
Sankarsan