Epson Expression 1680 - Manual (Page 101)

4-32 Options
1. Connect one end of the cable to any available IEEE 1394 port
on the Scanner I/F Card.
2. Connect the other end of the cable to the IEEE 1394 port on
your computer. If other IEEE 1394 devices are already
connected to the computer’s IEEE 1394 port, connect the
scanner to an available IEEE 1394 port on the last device in
the chain.
Note:
The cable supplied with the IEEE 1394 Scanner I/F Card has 2 six
pin connectors at each end. If IEEE 1394 devices with four pin
connectors are used in a daisy chain or tree, you will need to use a
6:4 converter cable.