Overview

Air circulation, lighting, and fire detection monitoring and control are vital functions in traffic control systems for tunnels. Most traffic systems rely on serial interface PLCs to manage these subsystems and provide real-time information to the control centre. A recent trend in traffic automation involves integrating fibre-optic cables into tunnel communication systems. Some governments have even requested fibre-optic cabling for all public communication systems due to the medium's extended distance capability and EMI immunity. However, most of the devices deployed in such applications, including the PLCs, do not come equipped with a fibre-optic interface.

System Requirements

- Extended distance between each station 
- Zero data loss from electromagnetic interference 
- High density solution saves space and wiring in the control Centre

Solution

Standalone serial-to-fibre media converters, such as the ICF-1150 series, offer an efficient way to solve this problem by equipping each serial interface PLC with fibre port connections. To save valuable space inside the control centre, Moxa's NRack system offers a high-density solution to house multiple fibre-optic converters on a standard rack. In addition, multiport serial boards, such as the CP-118U series, are required to expand the number of serial ports on a computer for transmitting data, commands, and programs between the host computer and multiple PLCs.