View source for Haxdb sensor node

The Sensor Node serves to monitor the condition of a support device, to prevent it being used when maintenance is required, and to prevent any dependent equipment from being used when the supporting device is offline.

''Sensor Nodes are physically differentiated from Tool Nodes primarily in that they have no need for RFID readers and, perhaps, LCD screens.''

== HVAC air handlers ==

The Sensor Node monitors the air filter indirectly by measuring differential air pressure. The condensate pump's integral alarm terminals are used to detect a failure to drain the condensate reservoir. If either requires service, the control signal from the associated thermostat is interrupted, preventing the air handler from running. Either a LCD or prominent LED beacon indicates an alarm state.

== filtration system ==

The Sensor Mode monitors the state of each of three filter stages via three differential air pressure sensors. When one of the filters requires replacement, this is signified via a LCD screen or one of three dedicated LEDs. A current sensor is used to detect when the filter system is running.

The HaxDB controller should track the associated tools -- eg, lasercutter -- and prevent their Tool Nodes from enabling them without the filter running first.

''Note: Filtration systems powered through VFD controllers can probably interface with the Sensor Node hardware digitally via a "run" signal, obviating the need for a current sensor. They can also probably be disabled with a digital signal, eliminating the need for a relay or contactor.'' 

== dust collection system ==

The Sensor Node monitors the state of the filter via differential air pressure sensor. When the filter requires cleaning, this is signified through a LCD screen or alarm LED. Until the filter is serviced, power to the dust collector is disabled.

After servicing the filter, users press the Fault button to inform the node. This re-enables the dust collector; if the filter hasn't actually been cleaned, this will be detected and the node disabled again right away.

The Sensor Node also disables the "start" signal of the dust collector sometimes, enforcing a "cool-down" between startups to prevent damaging the motor.

''Note: Should this enforced "cool-down" be available on Tool Nodes also? Are there other kinds of tools where motor damage is similarly possible?''

When the dust collector is running, this is detected via a current sensor.

The HaxDB controller should track the associated tools -- eg, table saw -- and prevent their Tool Nodes from enabling them without the dust collector running first.