Seagate BARRACUDA 9 ST19171WD - Manual (Page 43)

Barracuda 9 Installation Guide, Rev. B 41
WC/DC drives
WC/DC drives section Setting the SCSI ID jumpers
The SCSI ID for WC and DC drives is normally set over the SCSI
bus by the host system using connector contacts 39 (ID0), 40
(ID2), 79 (ID1), and 80 (ID3).
Terminating the drive
ST19171WC and ST19171DC drives do not have internal termi-
nators or any other way of adding internal termination to the
drive. You must provide external termination to these drives
when termination is required.