Safety and scope

This toolkit is for ventilators permanently withdrawn from patient care and used only for training. Mark the unit (TRAINING ONLY - NOT FOR PATIENT USE) before you start.

What a maintenance-clock reset is, and is not

The PREVENTATIVE MAINTENANCE DUE advisory is a timer, not a fault. Resetting it (OEM F3, or this toolkit's pm-reset) tells the ventilator that preventive maintenance was performed. It does not replace the filters, O-rings, leaf valves or battery, and it does not calibrate flow, mixer or pressure. The OEM manual (section Preventative Maintenance) requires that work at 2000 hours / 12 months for any unit in service.

For a training unit the clinical consequence of a stale calibration is nil, but the training consequence is not: delivered volumes shown on the LCD may drift from what an inline analyzer reads. If your curriculum uses the unit for volume-accuracy exercises, verify it with an inline analyzer (VentMon, PytuTester, or a commercial gas flow analyzer) after service and label the result.

Oxygen and gas

Never allow oil, grease or hydrocarbon lubricants near the DISS inlets, the compressor or the internal manifold. Use medical-grade air and oxygen at 50 PSI for any flow checks.

Electrical

The RS-232 port is on the AC power supply module. Connect the serial cable before powering the ventilator from AC, and use a USB-serial adapter whose ground is common with the laptop. If the laptop runs on mains power, use a grounded supply for both or a battery-powered laptop to avoid ground loops through the shield.

Active probing

eagle754 probe sends unknown bytes to the ventilator. Known facts that bound the risk:

• The calibration EEPROM is protected by a hardware pushbutton on a 2-pin header on the CPU board (OEM procedure 2.6: the protection register can only be changed while the button is held), so probing cannot alter protected calibration tables.
• The "Hold" state stops ventilation and shows FACTORY CALIBRATION; the probe detects the stream stopping and re-sends the same bytes to toggle out of Hold, then waits for you.
• Power-cycling the ventilator aborts any service state.

Still: never probe a unit connected to a test lung that someone could mistake for a patient circuit in use, keep the AC supply connected (a dying battery mid-procedure is the only realistic way to corrupt memory), and keep eyes on the LCD.

After the reset

Run MODE → CAL (the manual says a Transducer Calibration alarm follows an RTC reset), confirm 0 Hrs / 0 Dys in USER PROGRAMS, and record the event. Keep the captures/pm_reset_*.jsonl log with the unit's record; it contains every byte exchanged and the operator confirmations.