Hi
I have done something similar, which is to create a batch file on the pc which will open the drawer containing the following 2 lines
mode com1:9600,n,8,1
echo PleaseOpenMe > com1
The first line set up the com port so the till can communicate with the PC, the second line sends any sequence of charcters to the port which normally pings the drawer. The draw may have slightly different baud rates etc.
Within the Access database, when the till receipt is then printed i call a macro from the on-close event of the report which calls the batch file. A bit long winded I agree but it works !! (for me anyway)