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Mercury MUX8 Multiplexers


The Access Platform MUX8 adds flexibility to expand a single data line into multiple data lines to meet difficult system design and installation challenges. Common uses include star topology, wiring schemes, home-run wiring, or when wiring distances exceed the 4000 ft. limit of the RS-485 standard.

It utilizes bus-arbitration logic on a first-come, first-serve basis and can detect and deactivate a broken channel to protect the integrity of the communications bus. The MUX8 is an 8-port multi-device interface panel that provides the flexibility to take RS-485 or RS-232 wiring inputs to create 8 2-wire RS-485 communication channels

Application Notes

Mercury’s MUX 8 multiplexer accessory provides the ability to manage divergent system installations. Unmatched power, flexibility, and economy make the Mercury multiplexers an essential, reliable and efficient element for developing today’s sophisticated security systems in complex environments.


  1. Per port voltage isolation
  2. Universal system compatibilities across intelligent controller families
  3. RS-232 or RS-485 inputs accepted
  1. Conquer difficult installations
  2. Guard against good loop installation issues
  3. Flexibly expand data lines

System Diagram

Mercury Service Map


Primary Power:
DC Input: 12VDC ±15%, 250mA

  1. Port 1: RS-232/RS-485, selectable
  2. Port 3,5,7,9: RS-485, Transmit/Receive
  3. Port 2,4,6,8: RS-485, Transmit/Receive, or Receive Only

Wire Requirements:
  1. Power: 1 twisted pair, 18 AWG
  2. RS-485 24AWG 4,000ft (1,200m) max., twisted pair(s) with shield.
  3. RS-232 24AWG, 50ft (15m) max.

Temperature:0-70°C operational, -55-85°C storage

Humidity: 0-95% RHNC

5 in (127mm)L x 6in
(152mm)W x 1 in (25mm)H

4 oz (180 g) nominal

  • CE,
  • UL Compliant
  • RoHS

Ordering Information:

MFG Part # BluBØX Order # Description
MUX8 120-2600 Mercury - MUX8 8 Channel RS485 for Star Configuration

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