yamandu:
Finally solved the problem using a RS232 to TTL converter board and a null modem.Null modem was need just because both connectors are female, scanner and converter.
Thank you all.
Well a male to male null modem connector does more then just allow two female connectors to be attached to each other, as a null modem also crosses the send and receive signals and cross connects a few of the RS-232 control signals between the two connectors. There are straight-through gender changers that can connect two female connectors without changing any of the wiring paths and are simple called gender changers. a null model connector performs wiring modification and are avalible in male to male, female to female, or male to female configurations.
So if your set up works using the null model connector you selected then it was not just because you had two female connectors needing attachment to each other but rather also a change from DTE to DCE identity for one end of the two connections. A DTE serial device cannot direct wire to another DTE device as neither can a DCE wire directly to another DCE device, they must be of opposite identities.
Lefty