Our systems can monitor and control a number of different types of signs including:

Ematics have developed our own NMSC2 Protocol Interface Unit (PIU). This unit is effectively a straight replacement for the existing NMCS2 Transponder and communicates with the signs using Standard Highways Agency 5 byte NMCS2 messages via existing RS485 cables. The unit also provides an Ethernet interface and communicates with the Management & Information system via Modbus TCP protocol.

This unit has been used on many of our VMSS based projects and its placement includes the Butetown Tunnel VMSS, M6 junction 15 and and the Belfast M2 Bus lane Control. Using this unit provides many advantages including a more robust and extensible solution since it utilities an existing "Tried and Tested" software module and low cost standard off the shelf hardware.

This unit has been developed to be user configurable such that additional signs can be added in the future if required (PLC will accommodate up to 30 signs) and comes in "Master/Slave" and "Slave Only" versions allowing greater flexibility to suit the technical and fiscal needs of each individual project.

Typically, the Variable Message Signing Systems (VMSS) will be made up from two sub systems known as the Management and Information System and the Plant Level Control System.

The Plant level control System provides a PLC based interface with the plant level equipment, variable message signs and lane control signs within tunnel bores and external to the bores at the approach roads as required. Control software within the PLCs provides the VMSS control functionality and derivation of status information.

The Management and Information System provides the Supervisory Control and Data Acquisition for the Sign Monitoring and Variable Message Signing System. The SCADA Servers interface with the VMSS PLC, AND LCS PLC’s for the gathering of VMSS status information and issues commands to the PLC's as requested by the operator.

The NMCS2 Interface Unit is normally provided as part of the Plant Level Control System.

• Dual Redundant SCADA providing Monitoring & Control

• Standardised NMSC2 Communication to Signs

• Video Incident Detection

• CCTV Integration to SCADA

• Generic Design, Station Specific Design

• FDS / SDS / FAT / Installation Commissioning / SAT

• Documentation

• Training

• Warranty

• Safety Case

VMS Key Design Criteria

• Compliance with Highways Agency Standard Protocols

• Proven off the Shelf Technology

• Client – Server Architecture

• Integrated Data Management – Central Database

• Integrated HMI

• Scalable, Expandable

• Dual SCADA Servers – High Availability

• Future Migration Path

• Future Proof - Investment Protection

VMS Interfaces

VMS Key Design Criteria

• Monitoring and Control of VMS Signs (409, 421, LCS)

• SQL Database Driven Sign Plans

• Sign Plan Setting

• Sign Plan Preview

• Sign Plan Replay

• Sign Bright / Dim Selection

• Sign Aspect Maintenance

• User Security

• Control Priority

• Alarm And Event Handling

• Plan Edit \ Creation

• Data Logging And Archiving

• Historical Data Browser

• Help Facility

• User Account Administration

A Sign Plan is essentially a lookup table that identifies a list of all appropriate variable message and lane control signs from a planned action with an associated list of individual messages or aspects for each of the signs involved in the plan.

A number of these plans are created and stored in an SQL Database and can be selected and applied by the operator from the list. This saves the operator having to manually change each individual sign separately which would be time consuming and erroneous for large plans.

Authorised users can at anytime and subject to a security settings can create a new plan and add this to the list of available plans or edit any of the existing plans.

With our Sign Plan Preview, any plan can first be virtualised and applied to the system without actually interfering with any of the existing traffic scheme currently in play. This allows the operator to confirm and visualise the true effects of a selected plan before implementing. If the plan does not perform as expected then this will become apparent to the operator during the simulation and any possible mistakes or plan execution errors can be avoided.

Sign Plan Replay, is similar to sign plan preview except the plans simulated are actual plans that have been executed and its information archived. This archived data is read back from the file and information is then virtualised such that the SCADA "plays back" the plans from the archived time line.

This feature not only allows for post mortem or after the event fact finding but can be used as a training tool whereby real life events and operator responses can be considered during a training environment.

If you are considering such a project or require any further information then please contact us on +44 (0)161 836 7000 or email your request to mail@ematics.co.uk

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