Welch Allyn LC101 CO2 Module - User Manual - Manual (Page 49)

LC101 CO
2
Module OEM Implementation Manual Section 5 - Pneumatic Operation
Welch Allyn OEM Technologies Confidential Page 49
A condition of unstable operation may be evident when a partial blockage approaches the
occlusion threshold limits, causing the Module to toggle between normal and occlusion states. If
the blockage increases enough to completely occlude the inlet tubing, the Module reverts to the
total inlet occlusion state.
Total Exhaust Occlusion
A total blockage of the exhaust tubing, or total exhaust occlusion, is typically caused by an
obstructed external exhaust port or clogged internal muffler. In the event that this condition
occurs, the Pneumatic System ramps up the pump speed and remains in a high speed/no flow
state indefinitely. During this condition, the Module responds to status requests with a
Exhaust Occlusion Or Pneumatic Leak response.
WARNING The Module remains indefinitely in the total exhaust occlusion state if not
commanded by the host.
Partial Exhaust Occlusion
In the event of a partial blockage of the exhaust tubing, the Pneumatic System ramps up the
pump speed enough to maintain set flow rates. During this condition, the Module responds to
status requests with a Status OK response.
A condition of unstable operation may be evident when a partial blockage approaches the
occlusion threshold limits, causing the Module to toggle between the normal and occlusion
states. If the blockage increases enough to completely occlude the exhaust tubing, the Module
reverts to the total exhaust occlusion state.
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.