Manual - Fog421

Press and hold the button while applying power. Keep holding for 10 seconds until all three LEDs flash three times. This resets to:

When the red ERR LED illuminates, refer to this table (adapted from , Appendix A): fog421 manual

A: Confirm you are writing to the correct Modbus coil (address 0x01 for Relay 1). In manual mode, use the front-panel TEST button. Press and hold the button while applying power

| Interval | Action | Notes | |----------|--------|-------| | Daily | Visual check of LEDs and ventilation slots | Remove any dust or debris | | Weekly | Test both relays by forcing via Modbus (register 0x10) | Listen for audible click | | Monthly | Download and clear the data log | Prevents memory overflow | | Quarterly | Calibrate external probe (if used) | Requires FOG421-CAL kit | | Annually | Factory reset + firmware update | Check manufacturer website for new FW | In manual mode, use the front-panel TEST button

Pro tip: Save a copy offline to your phone or laptop. The manual’s troubleshooting flowcharts are invaluable during a field failure.