Covidien Nellcor GR101704, Service Manual

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Data Port Connectivity
Service Manual 7-5
Figure 7-1. DB-15 Pin Layout
The pin layout illustrates the pins viewed from the top to the bottom of the
D-shell. The conductive shell connects to earth ground when connected to
external equipment.
•
RS-232 Format — Pins 2, 3, and 5 provide RS-232 format data. When building
an RS-232 cable, do not add a resistor and keep cable length to a maximum of 25
feet.
•
RS-422 Format — Pins 1 and 4 (TxD+ and TxD-) are the differential transmit data
pair. Pins 9 and 12 (RxD+ and RxD-) are the differential receive data pair. They
provide RS-422 format data. When building an RS-422 cable, add a resistor (120
ohms, 1/2 watt, 5%) between pin 1 and pin 9 of the cable and keep cable length
to a maximum of 4,000 feet. Plug the end of the cable with the resistor added
into the monitoring system.
Table 7-3. DB-15 Signal Pinouts
Pin Signal Name Description Pin Signal Name Description
1 RxD+ RS-422 [+] input 9 RxD- RS-422 [-] input
2 RxD_RS232 RS-232 input 10 IGND Signal Ground, isolated
from earth ground
3 TxD_RS-232 RS-232 output 11 NC_232 Nurse call signal,
RS-232-level-output
4 TxD+ RS-422 [+] output 12 TxD- RS-422 [-] output
5 IGND Signal Ground, isolated
from earth ground 13 AN_PULSE Analog pulse rate output
6 AN_SpO
2
Analog saturation output 14 AN_PLETH Analog pleth waveform
output
7 NC_NO Nurse call relay closure,
normally open 15 F_NC_COM Nurse call relay closure,
common return, fused
8 NC_NC Nurse call relay closure,
normally closed