I am programing in Visual Basic 6. I need to know if it is possible to stablish a value of 0V in the pin2 of the port RS232 in order to do a reset of the engine connected to the computer through this port. thank you very much.

 

From what I know of RS232 you only got -15V and +15V. I think I would want to go through a solid state relay or something and use that to switch between 0V and whatever. Maybe put a diode infront of the intput of the SSR so you dont damage it with -15V (do they get damaged when they are reverse biased?).

http://www.opto22.com makes solid state relays.

Good luck!