The LNL-3300-M5 uses DIP switches for hardware-level addressing and configuration.

DIP switch S2 controls the operating parameters, memory clears, and network behavior.

: The default admin/password account is only valid for five minutes after DIP switch 1 is turned ON. It is critical to create at least one persistent user account before setting switch 1 back to OFF.

| Symptom | Likely Cause (per UPD manual) | Fix | | :--- | :--- | :--- | | Readers beep but no LED | D0/D1 swapped | Reverse data lines at terminal block. | | "Reader Tamper" in software | No EOL on reader tamper line | Connect tamper loop to an input or disable supervision. | | Relays chatter | Insufficient power supply | Measure voltage under load; must stay above 11.5V. | | OSDP fails intermittent | Missing bias resistors | Enable 680-ohm bias on bus or add external terminators. | | Board MAC address not found | Old crossover cable used | Use standard Cat5e/6 straight-through with MDIX switch. |

Onboard 10/104 Base-T Ethernet port (RJ-45) for direct upstream connection to the OnGuard server.