Nellcor N-395 Operator's Manual page 92

Data Port Protocol
(Information Technology Equipment) device must be certified to
UL-1950 or IEC-60950.
The cable used must have a braided shield providing 100%
coverage, such as a Belden cable (Belden part number 9609) or
equivalent. The shield must have a 360-degree connection to the
metal shell on the N-395's DB- 15 coilnector and to the connector
on the PC or serial printer. Do not create sharp bends in the
cable, as this may tear or break the shielding.
The pinouts (as illustrated in Figure 22) for the data port are
listed in Table 10.
Table 40: Data Port Pinouts
GND is ground, TxD represents the Transmit Data line, and RxD
is the Receive Data line.