Welch Allyn Duet CO2 Module - User Manual - Manual (Page 49)

Duet CO
2
Module OEM Implementation Manual
Welch Allyn OEM Technologies Confidential Page 49
Barometric Out Of Range
If the module is operated outside the allowable barometric range, the pump is turned OFF and the
module reverts to the fault mode. During this condition, the module responds to status requests with
either a Barometric Too High response or Barometric Too Low response.
Unexpected Reverse Flow
This condition occurs when the pneumatic input is connected to a negative pressure source, or
vacuum. The flow control circuitry checks the Pneumatic System for this condition prior to turning ON
the pump. If a vacuum exists on the inlet prior to the pump starting, the module reverts to the fault
mode. During this condition, the pump is not operational and the module responds to status requests
with Unexpected Reverse Flow response.
Unexpected Forward Flow
This condition occurs when the pneumatic input is connected to a positive pressure source, or flow
source. The flow control circuitry checks the Pneumatic System for this condition prior to turning ON the
pump. If a positive pressure exists on the exhaust prior to the pump starting, the module reverts to the
fault mode. During this condition, the pump is not operational and the module responds to status
requests with Unexpected Forward Flow.
Internal Disconnects
Internal disconnects which may occur include
§ Water trap receptacle § pump inlet
§ sample chamber § pump exhaust
§ flow control circuitry
Water trap Receptacle
If a pneumatic connection at the Water trap receptacle is loose or in failure, the transmission of CO
2
waveform and breath data packets is halted. The module does not report this fault to the host but clears
the breath data based on the default specified in the No Breath Timeout command.
Sample Chamber
If a pneumatic connection at the sample chamber is loose or in failure, the transmission of CO
2
waveform and breath data packets is halted. The module does not report this fault to the host but clears
the breath data based on the default specified in the No Breath Timeout command.
Flow Control Circuitry
If a pneumatic connection in the flow control circuitry is loose or in failure, transmission of CO
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waveform and breath data packets is halted. Pump operation may be unstable due to the lack of flow
control feedback. The module reverts to fault mode and may respond to status requests by issuing a
number of different fault codes.
Pump Inlet
If the pneumatic connection at the pump inlet is loose or in failure, transmission of CO
2
waveform and
breath data packets is halted. The set flow rate cannot be achieved since the pump is disconnected.
The module reverts to the fault mode and responds to status requests with an Exhaust
Occlusion response.