Analog Output - Nellcor OxiMax N-600x Service Manual

Data Port Interface Protocol

Analog Output

146
alarm and no alarm conditions, and for instrument off. Table 24 defines the ratings
of the Nurse Call Relay.
Table 23: Nurse Call Relay Pin States
Pin
7 N.O.
8 N.C.
Table 24: 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:
• 1.0 VDC Output for Saturation = 100%
• 1.0 Pulse Rate = 250 BPM
• 1.0 Plethysmographic Waveform = 254 Pulse Amplitude Units.
The voltage decreases as the values for these parameters decrease. If no data for a
parameter is available, the output voltage for that parameter is 1.0 VDC.
After the completion of power-on self-test (POST), the instrument initiates an
automatic three-step calibration signal. The calibration signal begins at 0.0 VDC
and hold that point for 15 seconds. It increases to 1.0 VDC and hold that value for
15 seconds. The third part of the calibration signal is a stair step signal. The stair
step signal begins at 0.0 VDC and increase up to 1.0 VDC in 0.1 VDC increments.
Each increment is held for 1 second. Through use of the softkeys, the 0.0 VDC,
1.0 VDC, or stair step signal can be selected individually (see Using the Analog
Output on page 27).
No Alarm or
Audible
Alarm
Alarm
Silenced
Open Closed
Closed 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
Instrument
Off
Closed
Open