9Control System#

The control system requirements defined in MRTS201 General Equipment Requirements apply to this Technical Specification. Additional control system requirements for equipment provided under this standard are described below.

9.1General function#

As a minimum the eTCS controller shall:

a)monitor, log and support TMS requests for its own operation and status
b)monitor, log and support TMS status requests for the sign
c)be capable of storing enough frames in its non-volatile memory to display each individual sign face
d)allow local automatic reset of the eTCS display and the eTCS controller itself such as via watchdog(s)
e)be capable of dimming the connected sign based on the light sensor outputs, and
f)accept / reject valid or invalid commands made by the TMS and/or PHCS.

9.2Local Facility Switch (LFS)#

A three-position key operated facility switch that complies with MRTS201 General Equipment Requirements, shall be provided to enable selection of the following five display functions for each of the text display and the graphics display:

1.BLANK / Maintenance, or
2.TEST, or
3.NORMAL

9.2.1BLANK / Maintenance Mode#

Where Blank / Maintenance mode is selected on a LFS the following requirement shall apply:

a) the eTCS sign shall remain powered
b) the hardwired sign display of that eTCS sign shall be blanked
c) any subsequent display requests from Product Host Control System (PHCS) shall be ignored
d) the PHCS software shall be permitted to perform all status, maintenance and diagnostic functions on the respective eTCS sign
e) where two signs have been configured as one pair, selecting the LFS to “BLANK” on one eTCS sign, shall not blank the other paired eTCS sign unit, and
f) the LFS shall be designed as fail-safe operation and as such should it fail or be disconnected, Blank / Maintenance mode will be activated.

9.2.2TEST mode#

Where TEST mode is selected on the LFS the displayed message is selected via the maintenance communications port and/or the control communications port. The followings shall apply:

a) the hardwired sign display of that eTCS is active
b) the eTCS shall ignore any subsequent display requests from Product Host Control System (PHCS)
c) the eTCS shall permit the PHCS software to perform all status, maintenance and diagnostic functions
d) the eTCS shall ignore remote control communications from the TMS or designated local HHD (refer Clause 9.11), and
e) the eTCS shall permit remote communications with a PC / Laptop running the eTCS Software.

9.2.3NORMAL mode#

Where NORMAL mode is selected on the LFS the displayed message is selected via the maintenance communications port and/or the control communications port. The followings shall apply:

a) the hardwired sign display of that eTCS is active
b) the eTCS shall accept remote control communications from the TMS
c) the eTCS shall accept remote communications with a PC / Laptop running the eTCS Software, and
d) the eTCS shall accept remote control communications from a designated local HHD (refer Clause 9.11).

9.3Controller operation / interrogation#

Each eTCS shall be operated by an integral control system that is controlled in the following order of priority:

1.maintenance communications port, and
2.control communications ports.

Software shall be provided in accordance with Clause 9.8.

9.3.1Maintenance communications port#

It shall be possible to control and interrogate the eTCS via an EIA/RS-232 maintenance communications port via the eTCS controller. The RS-232 port shall allow local and remote communications via a laptop computer (provided by others) containing eTCS messaging and diagnostics software to be provided by the Contractor. The maintenance communications port shall also allow remote connection of a similar computer via a modem.

A physical change of connection between remote and local operation shall not require further interaction from the user, nor in anyway interrupt operation or require rebooting of eTCS control system or computer / software. The hardware handshaking lines of the EIA/RS-232 interface shall be used such that connection / disconnection of the maintenance PC (either locally or by modem) results in the immediate initiation / termination of the maintenance port communications session with the eTCS.

The eTCS control and diagnostics software shall be capable of operating at all possible modem connection and serial port speeds.

9.3.2Control communications port#

It shall be possible to control and interrogate the eTCS via either of two EIA/RS-232 control communications ports. The control communications port shall allow local connection of a field processor / modem for communications with TMS.

While a PC / laptop computer is connected to the eTCS via the maintenance communications port, control of the eTCS via the control ports shall be inhibited. However, status and diagnostic interrogation by TMS via the control ports shall remain possible.

Complete control and monitoring by TMS shall be possible through both control communications ports as determined by telecommunications infrastructure provided at each Site.

Where communications equipment is connected to only one control communications port (or in the case of failure of either communications port or attached equipment) the eTCS shall automatically revert to full control AND status communications through the active port.

eTCS communications software shall be capable of operating at all possible modem connection and/or serial port speeds.

9.4Communications timeout#

The eTCS controller shall be capable of monitoring loss of communications with the TMS and timeout after a specified period. When the eTCS controller is in the NORMAL mode, expiry of this time period shall cause the eTCS controller to blank the entire eTCS. This period shall be a configurable parameter. The eTCS controller shall also be capable of monitoring communications with the sign and timeout after a specified period when such communication is lost. Communications timeout check shall be performed periodically and shall be a configurable parameter. In BLANK / Maintenance mode, the communications timeout check with the TMS shall be ignored.

9.5Configuration management#

All settings in the eTCS controller shall be accessible via the PHCS.

9.6Monitoring and logging#

9.6.1Sign fault management#

The eTCS controller shall monitor and log the following fault conditions:

loss of communication with the sign
high enclosure temperature
illumination faults, and
other faults relating to the eTCS.

9.6.2Local event logging#

The eTCS controller shall log in non-volatile memory, operational and fault events such as message changes, hardware resets, establishment or discontinuation of communications, local manual operations and clearance of faults. Each event shall be date and time stamped, accurate to at least one second. Once a fault has occurred and been logged, a recurrence of the same fault need not be logged again until after the fault has been cleared.

The event log shall have space for at least 255 entries. Where separate logs are used for operational and fault events, each log shall have space for at least 255 entries. The oldest event record shall be overwritten first when this allocated space has been exceeded.

All log entries shall be available for upload from any and all communication ports upon request from the Traffic Management Centre (TMC) and/or PHCS. The log shall be uploaded in order of most recent to oldest record. A request by the TMS for the event log shall provide for no less than 20 entries at a time.

Events shall be retained in the log even after retrieval by the PHCS and/or TMS.

9.6.3Watchdog#

The eTCS controller and the sign shall monitor the state of its respective processor and blank the respective display(s) if a critical internal fault is detected that could result in confusion to the public.

9.7Time synchronisation#

The eTCS controller shall be provided with an internal system clock in accordance with MRTS201 General Equipment Requirements and allow synchronisation of the clock in response to a TMS and/or PHCS command.

9.8Control / diagnostics software#

The eTCS integral control system shall fully implement all eTCS functions.

Communication between the Field Processor and the eTCS shall comply with MRTS201 General Equipment Requirements.

The computers may use Microsoft Windows® operating systems, from Windows 7 to those industry standards current at the time of use. Any software provided shall be capable of operating on all such operating systems.

The software shall report the selected mode on the facility switch.

Unauthorised use of the eTCS shall be prevented. Seed offsets and password offsets shall be unique to each sign.

9.9LED intensity control#

The LED intensity shall be controlled to provide constant apparent brightness, and maximum legibility distance, for the complete range of ambient light under which the eTCS shall operate.

Each eTCS shall support automatic brightness variation, where the eTCS determines the LED brightness level using a light sensor reading and a predefined set of light sensor values.

Each eTCS shall be provided with at least one light sensor to detect ambient light levels.

The dimming facility should reflect the ambient light conditions immediately on “switch on”, i.e., if the sign is switched on at night, the display shall be dimmed and if the sign is switched on during bright daylight, the display should be optimum brilliance without delay.

The dimming circuit shall have a switching delay of 30 ± 5 seconds.

Where a sign is in close proximity to artificial lighting, the ambient light level local to that sign may be artificially high. This may result in the dimming system setting the light output of the sign too high. Therefore, each sign and/or dimming circuit shall be capable of adjusting the dimmed light levels through a “brightness offset” to compensate for local artificial light levels.

9.10Bus arbitration#

Each eTCS shall act as a slave on the EIA RS–422A / modem bus.

9.11Hand-Held Communication Device (HHD)#

Where a hand-held communication device is required by the Principal as a local method of control, the HHD shall:

have a unique ID that is transmitted with each message change request
shall have priority over TMS message should a TMS message change request occur at the same time as the message change request from a HHD, namely, the TMS request shall be ignored
for wireless HHD, use “code hopping” or “rolling code” technology, to prevent unauthorised use of the signs through “replay attacks” for wired HHD, the leads shall preferably be securely terminated in the RS-232 port of the eTCS sign or any other secure termination resulting in 15 m lead
the CU shall have the ability to deactivate a HHD from controlling the eTCS sign (e.g., due to lost or damaged HHDs), through the eTCS configuration or RSCS software, and
only when a HHD message activation button is pressed and held for two seconds shall a control message be transmitted.

To guard against accidental activation of an eTCS frame from the HHD, buttons shall be pressed and held for two seconds before any eTCS message frame will be changed.