on my left i have a turnstyle gate offering access to a gym. if you press a doorbell on the receptionists desk the gate opens. (two wires, touch them together and the gate opens. )

on my right i have a pc that presents an rs232 port and wants to tell the gate to open. Its running software that supports this ability but i cant connect the two together.

there was a device in use on an older pc that has now been replaced.

i think i need a relay controller board with the ability to program the thing to close the connection between the two wires following a command from the Rs232 board.

can anyone help.

 

This is not nearly enough information for anyone to give you an intelligent response.