IAC Troubleshooting

Overview

The IAC provides extensive diagnostic information through on-board LEDs and LCD Terminal error messages.

Technical Details

Status and Fault LEDs

• Normal Operation: Status 1 and Status 2 LEDs flash alternately.
• Booting: Status 1 ON, Status 2 OFF.
• No SD Card: Fault 1 ON, Fault 2 OFF.
• NVRAM Not Initialized: Fault 1 FLASH, Fault 2 OFF.
• Database Error: Fault 1 FLASH, Fault 2 OFF (while Status 2 is ON).

LAN Troubleshooting

• LAN Dead: Check voltages at the Control Module (11-14V DC on LAN +ve).
• Intermittent LAN: Check for Earth Loops or interference from heavy machinery.
• Module Faults: RX/TX LEDs on modules indicate addressing or licensing issues.

LCD Terminal Messages

• No Rx: Terminal not receiving reply from Controller.
• Can’t Tx: Data cannot be sent (check A/B reversal).
• Too Many: Too many modules for the license level.

Configuration / Programming

• Initialization Procedure:
  1. Disconnect power.
  2. Short IN1 (Installer Code) or IN1 & IN2 (Full Default).
  3. Power up.
  4. Wait for Prompt LED to flash.
  5. Short OK.

Related Pages

• IAC Overview
• RS485 LAN System