LAN Isolator

Overview

The LAN Isolator (P/N: 995080PCB&K) provides 5kV electrical isolation and signal restoration for RS485 LAN sections. It is transparent to the system controller and does not require an address, serving as a vital component for surge protection and distance extension.

Technical Details

Compatibility

  • Compatible with Integriti, Inception, and legacy Concept 3000/4000/5000 systems.
  • NOT compatible with legacy Concept 1000/2000 systems.

Features

  • Electrical Isolation: 5kVrms (minimum 2.5kVrms on older units).
  • Signal Restoration: Regenerates RS485 LAN signals to extend LAN distance by up to 1500m.
  • Improved Protection: Actively monitors sections and can “isolate” branches where severed cables or abnormal conditions are detected.
  • Transparency: Transparent to the Control Module; does not generate LAN messages or require a module address.

Electrical Specifications

  • Power Supply Input: 11V to 14V DC (typically derived from connected LAN sections or from a separate external PSU).
  • Installation Environment: 0°C to 50°C (32°F to 122°F), 15% to 85% Relative Humidity (non-condensing).
  • Current Consumption:
    • LAN 1 (Uplink): 28mA (Standby) / 65mA (Busy).
    • LAN 2/3 (Downlinks): 15mA (Standby) / 30mA (Busy) each.
  • Voltage Checks: A to B: 200 - 600mV DC. A or B to GND: 200mV - 3.2VDC.
  • Physical Dimensions:
    • PCB Only: 140mm (L) x 95mm (W).
    • In Enclosure: 252mm (L) x 263mm (W) x 85mm (D).
  • Mounting: The PCB must be mounted using Nylon Screws and Spacers (not metal) to provide maximum immunity to lightning and surge voltages.

Terminal Pinouts

TerminalLabelFunctionConnection Notes
T1.1POSLAN Power (+)Connect to Control Module POS.
T1.20VLAN Power (-)Connect to Control Module 0V.
T1.3ARS485 LAN AUplink Data A.
T1.4BRS485 LAN BUplink Data B.
TerminalLabelFunctionConnection Notes
POS+VLAN Power (+)Downstream Power (Fused).
0V0VLAN Power (-)Downstream Ground.
AARS485 LAN AIsolated Data A.
BBRS485 LAN BIsolated Data B.

Status Monitoring (T4)

TerminalLabelFunctionConnection Notes
OUT1C / NOLoop FailCloses if Loop wiring is cut.
OUT2C / NOBranch IsolatedCloses if Branch is suspended.

Note: OUT1 and OUT2 include on-board End-of-Line resistors (2k2/6k8 scheme). They are wired directly to Zone Inputs — no external EOL resistors are needed. This scheme is compatible with Integriti, Inception, and Concept platforms.

Cabling Configurations

General Rules

  1. Uplink: LAN 1 must always be connected to the Control Module or a section providing a return path to it.
  2. Series Limit: A maximum of 3 LAN Isolators can be installed in series between any two modules.
  3. Distance: Each isolator extends the LAN by up to 1500m. When used for distance extension, the isolator must be installed no more than 1.5km from the Control Module or the previous LAN Isolator.
  4. Loop Mode: If a loop is used, it must be wired between LAN 2 and LAN 3. The total loop distance must not exceed 1.5km.
  5. No Series with Loop: A LAN Isolator must NOT be installed in series with a loop. The length of a loop cannot be extended by adding another isolator in series.
  6. Placement: It is recommended to install isolators near the Control Module to isolate external cabling from the core system.
  7. Concept Systems: When used in Concept 3000/4000 systems, fit LAN Termination Links as required. Refer to the Control Module Installation Manual.

Monitoring and Troubleshooting

Status Outputs

The LAN Isolator provides two dry relay outputs for status monitoring. These should be wired to Zone Inputs on the nearest module on the Uplink side:

  • OUT1 (Loop Fail): Monitors “Loop Mode” vs “Branch Mode”. Triggers if a loop connection is cut. When the loop cabling is restored, the isolator automatically switches back to “Loop Mode” on next LAN activity.
  • OUT2 (Branch Isolated): Triggers when the isolator has suspended activity on a branch due to a fault or tamper. When the fault is rectified, communications are automatically re-established.

Fire Protection

This product must be installed into a suitable non-flammable equipment enclosure on a non-flammable surface, away from all flammable materials. Any unused conduit entry points with knockouts removed must be resealed with Conduit Plugs.

LAN Initialization

In systems with multiple isolators, LAN initialization (Secure/Init) may take a few seconds longer than usual. This is normal behavior due to the propagation delay introduced by the isolators.