Nddn-w57 Reset Guide

Technical Report: Comprehensive Reset Procedure for NDDN-W57 Report ID: NDDN-RST-2026-04 System Version: NDDN-W57 Date: April 18, 2026 Subject: Full system reset – causes, procedure, validation, and post-reset configuration 1. Executive Summary The NDDN-W57 unit requires a full reset to restore factory default parameters, clear non-volatile error logs, and reinitialize communication stacks. This report details the hardware and software reset mechanisms, step-by-step execution, safety considerations, and verification metrics. A reset is recommended only after troubleshooting confirms irrecoverable state (e.g., watchdog timeout, corrupted configuration CRC, or persistent fault code 0x57E3). 2. Equipment & Preconditions | Item | Specification | |------|----------------| | Model | NDDN-W57 | | Firmware minimum version for safe reset | v3.2.1 or later | | Power input | 24V DC ±10% (or as per device label) | | Backup battery (if present) | CR2032 (retains real-time clock) | | Required tool | Magnetic probe (for reed switch) or terminal access via RS-485/Modbus | Pre-reset checks:

Confirm no active write cycle to internal EEPROM. Record current IP/Modbus address (if applicable). Capture active fault log via diagnostic LED blink code or GET_ERR command.

3. Reset Types | Reset Level | Trigger Method | Erased Data | Preserved Data | Use Case | |-------------|----------------|-------------|----------------|-----------| | Warm (soft) | Short power cycle (<2s) | RAM, temporary buffers | Configuration, logs | Unresponsive UI | | Cold (hard) | Power off ≥30s | RAM, buffers | Configuration only | Communication freeze | | Factory (default) | Magnetic probe + power-on sequence | All user settings, logs, calibration | Hardware serial number | Configuration corruption | 4. Factory Reset Procedure (NDDN-W57) Step 1 – Power Down Disconnect both primary and redundant power sources. Wait for all LEDs to extinguish (approximately 15 seconds due to internal capacitor bleed). Step 2 – Enter Reset Mode

Locate the MAG-RST area (top right corner, marked with a crescent icon). Hold a magnetic probe (minimum 50 Gauss) against the enclosure at that spot. While holding the magnet, reapply power (24V DC). nddn-w57 reset

Step 3 – Observe Acknowledgment

Status LED: Flashes amber‑red‑green three times. Buzzer (if equipped): Two short beeps. Release the magnetic probe immediately after the third flash.

Step 4 – Wait for Reset Execution

Internal microcontroller erases user configuration sector (address range 0x3E00–0x3FFF). Restores default baud rate (9600, 8N1), default Modbus ID (247), and default fallback IP (192.168.1.100 for Ethernet variants). Duration: Typically 8–12 seconds.

Step 5 – Automatic Reboot

Device restarts in factory state. LED settles to steady green (normal operation) or slow blinking green (waiting for configuration). A reset is recommended only after troubleshooting confirms

5. Post-Reset Validation Run the following verification tests: | Test | Expected Result | Failure Action | |-------|----------------|----------------| | Power-on self-test (POST) | All diagnostic LEDs cycle once | Repeat reset with longer magnet hold | | Communication loopback (local) | Send AT command → returns OK | Check serial wiring or USB driver | | Default register read (Modbus) | Read holding register 0x0001 → returns 0x5757 (signature) | Replace firmware via bootloader | | Real-time clock (if battery) | Compare time with reference | Replace backup battery | 6. Reconfiguration Mandatory Steps After reset, at minimum reconfigure:

Communication parameters (baud rate, parity, stop bits) to match your bus master. Device address (avoid conflict with existing node). Alarm thresholds (e.g., temperature, vibration, pressure – refer to original application spec). Logging interval (default is 1 minute; set to desired value via register 0x0120).