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 - 41
3
CPR Mode
While in the CPR mode, all trim points are increased to new values as in the
auto firm mode. However, the head and seat zones are inflated to these new
values first. When these zone pressures reach their trim points, the knee and all
three heel zones are inflated to their trim points. Pressures are then regulated,
as described in the pressure relief mode, at the new trim points. When this
mode is entered, a 60-min timer is started. If this timer expires before the
system is placed in a different mode, the system automatically returns to the
previous mode.
Initiate the transition to the CPR mode by pulling a CPR lever while in any
mode except the off mode.
Mode Transition
Power Up
By design, the system always powers up in the pressure relief mode. If the bed
is plugged in and the air system is off, turn on the system by pressing the
surface power switch.
During transition from the off mode to the pressure relief mode, the following
occurs:
• The low voltage AC/mattress power relay is activated, and all I/O is
initialized.
• All errors are cleared.
• All timers and counters are initialized.
• Proper footboard control panel LEDs are lit.
• New mode (pressure relief mode) is stored in the on-chip EEPROM.
• Calibrations are read from the pressure sensing circuit EEPROM, and
pressure trim points are calculated.
• Pressure out-of-range delay timers are defeated to allow immediate
correction.
• Pressure tolerance bands around the trim points are calculated.