Hill-Rom Advanta P1600, Service Manual

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ZoneAire® Sleep Surface Software Theory of Operation
Chapter 3: Theory of Operation
Advanta™ Bed Service Manual (man168ra) Page 3 - 45
3
Whenever an EEPROM error is detected, the operating mode transitions to off,
and the footboard control panel service required LED repeatedly flashes code
2, 4.
Mattress Connection Error
In all modes, except the off mode, the electrical connection between the
control circuit and the pressure sensing circuit is monitored. Also, prior to
reading the calibrations from EEPROM (at reset and power up), the control
circuit checks the connection. It checks by sampling the pressure sensing
circuit voltage feedback routed through the mattress cable.
The mattress connection error is set when feedback indicates disconnection at
two different times:
• After 100 continuous samples (approximately 5 s).
• Prior to reading EEPROM.
Whenever a mattress connection error is detected, the operating mode
transitions to off, and the footboard control panel service required LED
repeatedly flashes code 2, 5.
Triac Open Error
In all modes, except the off mode, the system is repeatedly checked for control
circuit failure that would prevent activation of an air manifold valve, the flow
direction valve, or the pump when commanded to activate.
Whenever the system is correcting pressures, the feedbacks from the triac drive
circuits are monitored. If any feedback indicates that a drive circuit is not
activated continuously for 5 s, a triac open error is flagged, the operating mode
transitions to off, and the footboard control panel service required LED
repeatedly flashes code 2, 6.
LON Communication Error
In all modes, except the off mode, communications with the footboard control
panel is checked. The Advanta™ Bed ZoneAire® Sleep Surface system gets
updates, via LON communications, from the footboard control panel, at most,
every 30 s. The system refreshes a 5-min timer whenever it gets this update.
Should this timer ever expire, a LON communication error is flagged and the
operating mode transitions to off. A message is sent to the footboard control
panel to flash the service required LED for code 2, 7. Of course, chances are
that the footboard control panel will not get this message. However, the