Can anyone help please?
Need to fit a coinbox to a KM-1635 but can not find a way to ensure that 2 coins are needed to use the A3 cassette.A4 will accept and work correctly with a single coin but can not pick up a signal to tell the coinbox that it is an A3 copy that is required so that it will not allow a copy from this tray until 2 coins have been inserted.
Any ideas will be greatly appreciated.

The only way I have been able to do this on the KM machines is to use the cassette empty switch and have the coin-op close the switch when enough credit is added.