Analog Output; Table 20: Nurse Call Relay Pin States; Table 21: Rating Of Nurse Call Relay - Nellcor OXIMAX N-595 Service Manual

Data Port Interface Protocol

Analog Output

106
pins 10 and 11 will be -5 VDC to -12 VDC, or +5V DC to +12 VDC,
depending on the option chosen via the softkeys (either NORM+ or
NORM-). Whenever there is an audible alarm, the output between pins 5 and
11 will reverse polarity.
An internal Nurse Call relay (pins 7, 8, and 15) provides dry contacts that can
be used to signal a remote alarm. Pin 15 is common, pin 7 is normally open
(N.O.), and pin 8 is normally closed (N.C.). Table 20 on page 106 shows the
state of the contacts for alarm and no alarm conditions, and for instrument off.
Table 21 on page 106 defines the ratings of the Nurse Call relay.

Table 20: Nurse Call Relay Pin States

No Alarm or
Pin Alarm
Silenced
7 N.O. Open
8 N.C. Closed

Table 21: Rating of Nurse Call Relay

Maximum Input Voltage
Load Current
Minimum Resistance
Ground Reference
Electrical Isolation
Analog outputs are provided for Saturation, Pulse Rate, and a
plethysmographic waveform.
The output voltage is 0.0 to +1.0 VDC for all three parameters. A 1.0 VDC
output for saturation equals 100%; for pulse rate it equals 250 bpm; and for
plethysmographic waveform, it equals 254 pulse amplitude units. The voltage
will decrease as the values for these parameters decrease. If no data for a
parameter is available, the output voltage for that parameter will be 1.0 VDC.
After the completion of power-on self-test (POST), the instrument will initiate
an automatic three-step calibration signal. The calibration signal will begin at
0.0 VDC and hold that point for 15 seconds. It will then increase to 1.0 VDC
and hold that value for 15 seconds. The third part of the calibration signal is a
Audible Instrument
Alarm Off
Closed Closed
Open Open
30 VA or DC (polarity is not important)
120 mA continuous
(peak 300 mA @ 100 ms)
26.5 ohms to 50.5 ohms (40.5 ohms typical)
during alarms
Isolated Ground
1500 Volts