RTM300 VEHICLE SENSOR
RTM500 INTERFACE CARD
INSTRUCTION MANUAL
Incorporating Type Approval
Maintenance Provisions
APPLICATION
Vehicle Sensor for use in sub-surface locations for
vehicle detection as an alternative to inductive loop or
similar technologies.
CONTENTS
1
DESCRIPTION
2
SPECIFICATIONS & EU DIRECTIVES
3
MODIFICATIONS
4
REPAIRS
5
WARNINGS
6
INSTALLATION
7
TESTING
8
DECLARATION OF INCORPORATION
9
TECHNICAL DATA
Document No: TAMPRTM.DOC
Written:
BPC
Issue:
4
Checked:
LS
Date:
23 MARCH 2015
Approved:
BPC
1
DESCRIPTION
The RTM300/500 vehicle detection system monitors changes in the earth’s
magnetic field caused by passing vehicles and signals this change to the
controller as a detection event.
The RTM vehicle sensor system - comprising the RTM300 sensor and the
RTM500 interface card - is specifically designed for use at traffic signal controlled
locations for the detection of vehicles. It has been designed to be retrofitted at
failed loop locations and can also be installed at new locations during site
refurbishment or during site highway works.
It is easy and quick to install, with the interface card fitting into the controller in
exactly the same manner as a loop detector card, and the sensor into available
ducting, or as defined in section 6 below.
Each RTM500 interface card can support up to 4 RTM300 sensors. Each sensor
takes power and set up data from, and signals detection events to, the interface
card over a two wire link which may be either new or legacy loop feeder cable.
2
SPECIFICATIONS & EU DIRECTIVES
This Equipment has been designed to conform to:
Low Voltage Directive: 73/23/EEC
Electromagnetic Compatibility Directive: 89/336/EEC
BS 7671: 2001 AMD 9781
BS EN 50293: 2001
TR 2512A
TRG 0600B
3
MODIFICATIONS
There are no approved modifications.
4
REPAIRS
The RTM300 and RTM500 are entirely self-contained. Should either prove faulty,
no repair shall be attempted but it shall be replaced by another unit of the same
type. All suspect or faulty equipment shall be returned to the supplier for repair.
5
WARNINGS
.
5.1 Use of components other than those permitted herein, or modifications
or enhancements that have not been authorised by Radix Traffic Limited,
may invalidate the Type Approval and Warranty of this product.
5.2 Always observe precautions for the handling of electrostatic devices
where applicable.
5.3 Insulation Testing of Detector Feeder Cables. Before any 500v insulation
(Megger) tests are carried out to detector feeder cables, it is imperative that
any RTM300 sensors are first disconnected fully from all feeder cores.
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Leaving the RTM300 sensor connected whilst conducting a 500v insulation
(Megger) test will damage the sensor’s internal electrical components
rendering it unusable and invalidating any existing warranty.
6
INSTALLATION
CAUTION Ensure that all proper safety precautions are taken. Observe all
National and Customer codes of conduct and procedures whilst working on
any street furniture. Provisions should be made to ensure safe operation of
the crossing/junction at all times.
Confirm the operational modes required and set the front panel switches and
jumpers J1-4 of the RTM500 interface card accordingly.
Jumper Function
1
Output mode
2
3
4
Fitted
Low
power
Not Fitted Notes
Fail safe
Issue 3
(TR2512) and below
Not used
Not used
Not used
RTM500 Sensitivity & Presence Time Switch Settings
Sensitivity
S1
S2
0
1
0
1
0
0
1
1
Presence Time
LOW
MED LOW
MED HIGH
HIGH
P1
P2
0
1
0
1
0
0
1
1
CH OFF
3s
4min
35min
NOTE: This equipment is fitted with overvoltage protection to minimise the
disruption that may be caused by induced voltages from lightning or other
environmental effects.
6.1 INSTALLATION OF THE RTM300 SENSOR
6.1.1 The installation of the RTM300 sensor presumes that a suitable duct has
been installed, has sufficient capacity and is accessible. Where more than
one sensor is to be installed in the same duct, install the furthest sensor first
and work progressively to the nearest sensor.
Further information on the installation of ducts can be found in Appendix 3.
6.1.2 Attach a sufficiently long and suitable (e.g polypropylene) draw cord to the
attachment point on the sensor. Using the site plans or by measurement
along the kerb at 90° and at 45° (see figure 1 below) find the distance to the
white line. Half of this is the mid lane distance. Add on the set back of the
duct end in the pit from the kerb line to get the distance that the sensor has to
be pushed out. Measure off this distance on the draw cord and mark it using
suitable tape.
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Figure 1 - Measuring Lane Width from the Kerbside
Intended
sensor
position
Lane Width
at Kerb line
Pit
Setback
6.1.3 Terminate the loop feeder cable in the bottle joint. Connect the sensor
cable to the bottle joint. The sensor is not polarity sensitive. Close the bottle
joint in accordance with the manufacturer’s instructions. Coil the sensor cable
and draw cord to allow it to run freely. Ensure that any sensors already in the
duct have their draw cords and cables retained so that they are not displaced
during fitting of later sensors.
Where using legacy loop feeders, it is possible to common all the RTM300
cable low sides onto one core. See Appendix 2.
6.1.4 Using a push rod or other flexible guide, push the sensor down the duct
maintaining a constant positive force until the draw cord mark lines up with
the end of the duct. A recess is provided in the potting of the sensor to help
locate the push rod. When the sensor is in place withdraw the push rod and
make the draw cord off within the pit, preferably attaching it to the pit wall or
other fixed location.
6.1.5 Check the bottle joint to ensure that it is watertight and make the pit tidy
before closing it.
6.1.6 When all sensors are installed, return to the controller cabinet and fit the
interface cards in accordance with section 6.2 below.
NOTE: During subsequent site activity additional new cables may be
installed or existing cables may be replaced if damaged. After any such
operation that affects the duct, the sensor may move leading to a
possible unintended detection and a loss of position. To alleviate this, it
is recommended that once installed, the sensor cable should be
secured to the end of the duct with a tie wrap to prevent any movement.
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6.2 INSTALLATION OF THE RTM500 INTERFACE CARD
6.2.1 Controller cabinets typically support 3U rack space for the addition of loop
detector cards. Locate a space in the cabinet suitable for a 5HP (25mm) wide
Eurocard. Fit a backplane to this location and test fit the RTM500 interface
card to ensure that when it is inserted and aligned correctly, it engages fully
with the backplane connector. Fasten the backplane in position. Alternatively,
the RTM500 interface card can also be installed into Intelligent Backplanes.
6.2.2 Remove the RTM500 and connect the power from the controller to the
backplane, connect the loop feeder from the sensor location (the sensor
wiring pair is not polarity sensitive) and connect the wiring from the RTM500
output to the controller input. Where the installation is a replacement of an
existing loop, the feeder and output wiring will need to be moved from the
redundant channel on the loop detector card to the RTM500.
6.2.3 When all the RTM300 sensors have been installed and fitted, the RTM500
interface card can be inserted and the front panel screws that retain it can be
tightened.
7
TESTING
7.1 Set presence time switches P1 and P2 to the off (left) position for all unused
channels that will not have an RTM300 sensor connected to them. The
required presence time (normally 4 minutes for UK traffic control applications)
for all active channels should also be set.
When the RTM500 Interface Cards are installed and powered for the first
time, the yellow and red LEDs on the front panel will cascade down in
sequence twice and any sensors connected to any of the four channels will
then give a double pulse on the red LED to confirm that they are connected.
NOTE: On first time power up of the connected RTM300 sensors they revert
to the default settings of medium high sensitivity and 4 minutes
presence time, irrespective of which switch settings are set on the
RTM500 interface card. Any change to the default settings post power
up must be implemented by performing a full reset of the interface card.
Check the front panel yellow fault LEDs on each active channel, marked F1
to F4. These should be lit and unblinking for no fault condition. Fast blinking
(2Hz) indicates a short circuit on the channel, slow blinking (0.5Hz) indicates
an open circuit.
If the channels are fault free, the red detection LEDs CH1 to CH4 for any
active sensors can then be checked for correct operation and detection of
vehicles.
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Figure 2 - RTM500 Interface Card Front Panel Showing LEDs and Switches
Reset Button. Short
press (<3s) to re-alight
LEDs after power save.
Long press (>3s) for full
reset.
Yellow Fault LED. Lit
for channel on & no
fault. Flashing for fault.
Red detection LED.
Lit for channel on &
detection.
Channel sensitivity
and presence time
switch settings.
7.2 Check each active channel on the RTM500 Interface Card in turn and witness
a number of vehicles passing over the location of the sensor to verify that
there are corresponding detection events registered on the red detect LED
on the channel under test.
7.3 If some vehicles are not being detected or if a channel appears to be too
sensitive, then the sensitivity settings should be adjusted to improve vehicle
detection. The sensitivity settings are adjusted using switches S1 and S2 on
the front panel and the settings indicated on the product label or in section 6
above. Once a new sensitivity has been selected for the channel of interest,
a full reset must be performed by pushing and holding in the reset button for
greater than 3 seconds.
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Once held in, the yellow and red LEDs will cascade down and when they
begin to cascade down for the second time the reset button can be released.
A short flash on the red detect LED will appear on the adjusted channel or
channels only, which confirms that the RTM300 sensor has received the new
sensitivity setting. All other channels which have not been changed are not
reset and will keep detecting even during the reset period.
The sensitivity of the sensor can also be adjusted by moving the sensor
inside the duct either further out into the lane of interest or further back
towards the kerb line.
7.4 If necessary, the presence time can be adjusted using switches P1 and P2,
then following the same full reset process as described in section 7.3 above.
7.5 Use a handset to verify that the controller is responding to the outputs.
7.6 Perform any other acceptance testing as required in their procedures by the
local authority responsible for the site.
NOTE: To simplify commissioning, on RTM500 interface cards with
software version 18 and above (as indicated on the rear of the card),
adjusting switch settings to individual RTM300 channels and
performing a full reset will only reset the channels being adjusted and
not any other channels.
On earlier versions of software, a full reset of the interface card resets
all four channels at the same time.
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8
DECLARATION OF INCORPORATION
Page 8
Appendix 1 - TR2512 Typical Standalone Backplane Connections
The following diagram is representative of a typical standalone backplane. If in
any doubt about the connections, the backplane and/or controller manufacturer’s
handbook should be consulted.
The RTM500 uses opto-isolated open collector transistor outputs, NOT relays.
IMPORTANT NOTES
For Issue 3 and below hardware versions of the RTM500 Interface Card:There is NO change-over signal between the open to detect and close to detect
backplane outputs. The SAME output is provided on both the open and close to
detect, i.e. these are joined at the interface card.
Jumper position 1 (top two horizontal pins) on the card can then be used to invert the
output signal to get either open to detect OR close to detect (but not both) at the
backplane.
If the RTM500 is to be powered by a 24v AC power supply, the AC connections must
be made to pins 19 & 20 (the same as 24v DC supply). If left at pins 23 & 24, the
card will not power up.
For Issue 4 and above hardware versions of the RTM500 Interface Cards:Both open and close to detect outputs are provided for each channel through the
detector backplane connections as shown in the above diagram.
Separate connections are also provided for 24v AC and DC supplies and connection
must be made as shown in the above diagram.
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Appendix 2 - Commoning Feeder Cable Cores
Although the RTM300 sensors are polarity independent, the RTM500 interface
card drives the sensors with a supply and return line. Any number of sensors on
one interface card can therefore be commoned so that for all four channels, only
one common core and four sensor cores are needed - a total of five cores.
To identify which cores can be commoned together:

Remove all feeders from the backplane and fit an interface card with all
four channels turned on.

Use a DVM set to measure at least 20V.

Measure the loop feeders on each channel. With no sensor present
these will show a dc voltage of about 15V. The low side of each feeder
can be commoned and the high side should be treated as a separate
core.
Where a phase has either X,Y,Z detection (or for MOVA IN, X, SL) then all three
detectors may be connected back to the controller on a four core feeder. This has
to be broken into at the Z location and extended to the Y and then two cores run
to the X.
It is suggested that the black is used as the common, with the red being the
furthest detection point and blue and yellow used for the two closer detection
points.
It is recommended not to common between RTM500 cards.
Note. RTM500 outputs are protected against short circuits. If an error is
made during commoning, the channel fault LED will flash at about 2Hz
indicating a short circuit on that channel output.
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Appendix 3 - Guideline for the Installation of Sensors
As the RTM300 is typically installed inside a duct, this Appendix provides
supporting information on considerations for the duct design and installation.
This guideline should be read in conjunction with local and national
instructions, specifications and guidelines and are not a substitute for
them.
Duct Minimum Bend Radius
Ideally the inside of the duct should be smooth and the duct should be rigid and
straight over its entire length. If the site conditions are such that this is not
practical and a flexible duct has to be installed, consideration should be given to
the minimum bend radius to allow the RTM300 sensor to pass easily.
Duct Depth
The ideal depth of the duct to allow for resurfacing of the carriageway without
damage and for maximum flexibility of sensitivity adjustment of the RTM300
sensor, is 150mm below the surface. However subject to the nature of the
carriageway material the RTM300 sensor can operate down to 600mm below the
surface. Most traffic signals ducts are buried at 600mm cover, which places them
above other services.
Duct Diameter
The RTM300 sensor is approximately 18mm diameter, and we therefore
recommend an absolute minimum internal diameter of a 20mm duct for easy
passage of the sensor. If smaller diameter ducts are used, then care should be
taken that re-instatement of the carriageway does not distort the duct as this may
prevent easy passage of the sensor.
If more than one sensor is to be fitted inside a cross carriageway duct, allow
adequate clearance for the cable and draw cord for further sensors to pass by
the nearer sensor.
Choice of Duct Materials
The RTM300 sensor is less likely to work reliably if mounted within a
ferromagnetic duct, for example a duct with a steel liner or an old cast iron pipe.
Sealing The Duct
Where blind ducts are used, the far end must be sealed to prevent the ingress of
mud or other materials from the backfill which may clog the duct.
After sensors are installed, the chamber end of the duct may be loosely plugged
to minimise water and contamination ingress. Suitable sized pieces of bubble
wrap or foam are suitable for this purpose.
Alternative to Ducts
The RTM300 sensor does not have to be installed in a duct, and due
consideration should be given to alternative installation locations as follows:




the degree of protection offered to the sensor and cable.
the mounting of the sensor to prevent movement.
the loss of sensitivity with increasing distance from the vehicle to be
detected.
the savings in installation cost.
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Movement of Sensor
After installation, the sensor must not be able to move or be subjected to high
levels of vibration, otherwise false detect signals may occur.
Where a sensor is installed inside a duct from a footway chamber, it is
recommended that the sensor cable should be tie-wrapped to the outside of the
duct wall to prevent movement of the sensor or any accidental snagging from any
other cables that are subsequently installed in or through the chamber.
In some applications it may be acceptable to fit the sensor within a chamber or pit
using spring clips fastened to the chamber or pit wall.
Certain kerb materials are designed with a bore and may accept an RTM300
sensor.
Users are strongly advised to trial any mounting location before committing to the
final deployment.
Electrical Interference
As the RTM300 sensor detects changes in the earth’s magnetic field, it is
recommended that the sensor is not installed inside a duct that contains mains
cables, as these may affect the field strength and detector performance.
If High (HV) or Extra High Voltage (EHV) power cables are known to exist close
to the proposed sensor location, then a trial survey should be carried out before
installing the sensor to assess any potential impact on the sensor performance.
Page 12
Appendix 4 - Changing the Zone of Detection
There are several ways in which the zone and range of detection can be
adjusted, as follows:
Sensitivity
The higher the sensitivity setting, the wider the zone of detection.
The sensitivity should be set so that small vehicles (or those with small ferrous
content) are detected reliably, but larger vehicles in adjacent lanes are not
detected.
Position
Should it not be possible to achieve reliable detection in the lane of interest using
just the sensitivity switches on the RTM500 Interface Card, it may be possible to
re-position the sensors off centre (i.e either towards the kerb or further out from
the kerb) to achieve better results and lane discipline.
Multiple sensors per lane
In rare situations, it may be desirable to install two or more sensors per lane and
then connect their outputs from the RTM500 Interface Card in parallel to the
controller detector input.
This improves the chance of detecting certain vehicles across a larger lane area
by allowing any of the sensors to provide a detect output to the controller.
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9
TECHNICAL DATA
ELECTRICAL
Nominal Supply Voltage RTM500: 24V dc or 24V ac
Operating Range: 19.0V to 29.0V
Nominal Power Consumption: 2.4W
MECHANICAL
Sensor RTM300 Dims: 17.2mm dia x 155mm long
RTM300 Standard Cable Length: 8.0m
Interface Card Dims: 3U x 5HP 160mm Eurocard to TR2512
RTM300 Weight (unpackaged): 475g
RTM500 Weight (unpackaged): 200g
ENVIRONMENTAL
Operating Temperature Range: -15ºC to +70ºC
Storage Temperature Range: -20ºC to +80ºC
RADIX TRAFFIC LIMITED
D3 Premier Centre, Abbey Park
Romsey, Hampshire SO51 9DG, England
Tel: 01794 511388
email: [email protected]
web: www.radixtraffic.co.uk
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