In my application i am printing invoices by dot matrix printer.
Now I have to implicitly eject extra paper so that i can easily tear it from the perforated line.But for the next invoice it is esential to reverse feed the paper so that the printing starts from the top.
The problem is how to reverse feed the paper.Is there any command for it .or simply the printing should start from the beginning of the paper.I am using tvs msp seri---350 paper length is 4 inch

Well before you do, you'd better check whether the tractor feed which drives the paper through the printer is before or after the print head.

If it's after, then you might not be able to go far enough back without dropping traction.

The other alternative is to go forward one page, but that wastes a whole sheet of paper. You minimise loss by printing as many invoices as possible in a run.