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Customized Loop Detector
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Customized Loop Detector USER MANUAL Version 1.00 1. INTRODUCTION Dual channel vehicle loop detector based detector designed specifically for parking and vehicle access control applications. The primary function of the detector is to detect vehicle presence by means of an inductance change caused by the vehicle passing over a wire loop buried under the road surface. The various modes are selected by changing the position of switches on the front of the unit. The detector oscillator is multiplexed to eliminate any possibility of crosstalk between the loops connected to the detector. The switches allow for different loop frequency settings, sensitivity settings and modesettings. The unit has a number of initial selectable options for configuration of the relay outputs. The PD-230 provides visual outputs ( LED ) on the front of the enclosure and relay change-over contacts at the 11 pin connector at the rear of the enclosure. The power LED indicates that the unit has been powered. The channel status LED鈥檚 below indicate that a vehicle is present over the loop and when there is a fault on the loop. The Presence relays are normally fail-secure and will close on a vehicle detect or loop failure but not if there is a power failure. 2. TECHNICAL DATA TuningFully automatic Self-tuning range50 to 1000渭H SensitivityFour step switch selectable FrequencyFour step switch selectable Frequency dependent on loop size ModesOutput relays operate in the Presence ( fail-secure ) Pulse or Direction logic modes Presence TimeSwitch selectable Limited presence Permanent presence Pulse Output Duration500 millisecond options Response Times20 milliseconds Visual Indication1 x Power LED - Red 2 x Channel Status LED - Green Relay Outputs2 x Relays rated - 5A @ 230 VAC ResetReset by push button on front of enclosure Power requirements12 - 24V AC/DC 卤 15% ( PD-230 ) 120V AC 卤 15% ( 50 to 60Hz ) ( PD-231 ) 230V AC 卤 15% ( 50 to 60Hz ) ( PD-232 ) Operating Temperature-40掳C to +85掳C Mounting PositionShelf or DIN rail mounting 3. Switch Setting Selections 3.1 Frequency Switch The frequency switches are the lower two switches, numbered 1 and 2. There are two frequency selections and are set out as follows: Loop2 Frequency: SW1 OFF 鈥?High, ON 鈥?Low Loop1 Frequency: SW2 OFF 鈥?High, ON 鈥?Low The frequency switches allow the loop frequency to be shifted higher or lower depending on the switch position. The frequency of the loop is determined by the loop size, and the frequency of the switch simply causes a frequency shift on the loop. Where more than one detector is used the detectors must be set-up to ensure that there is no cross-talk (interference) between the detectors. This can be achieved by ensuring that the loops of the two detectors are spaced sufficiently apart ( approximately 1~2 meters between adjacent edges ) and also ensuring that the detectors are set to different frequencies. As a general rule, the detector connected to the inductive loop with the greatest inductance should be set to operate at the lowest frequency. Loop inductance increases as loop size, number of turns in the loop and feeder length increases. When the switch selection is altered, the frequency of the loop will changes and you must be reset the detector. 3.2 Sensitivity The sensitivity of the detector allows the detector to be selective as to the change of inductance necessary to produce an output. There are four sensitivity selections and are set as follows: CH1 SW6 SW5 CH2 SW4 SW3 Off Off - Higher On Off - High Off On - Low On On - Lower 3.3 Automatic Sensitivity Boost Automatic sensitivity boost is a mode which alters the undetect level of the detector . This mode is selected by switch No. 7 on the front of the enclosure and is set as follows: - SW7 Off - Disabled On - Enabled Automatic sensitivity boost causes the sensitivity to be boosted to a maximum on detection on the vehicle, and maintained at this level during the presence of the entire vehicle over the loop. When the vehicle departs the loop and detection is lost the sensitivity reverts to the pre-selected level. 3.4 Presence Time The presence time may be set to permanent presence or to limited presence. In permanent presence mode the detector will continuously compensate for all environmental changes whilst there is a vehicle present over the loop. In limited presence mode there will be a finite time that the detector will remain in detect. This time is dependent on the change of inductance that the vehicle caused. The presence mode is set with switch No. 8 and is set as follows: SW8 Off - Limited Presence On - Permanent Presence 3.5 Reset Switch The detector automatically tunes to the inductive loops connected to it when power is applied, whether on initial installation or after any break in the power supply. Should it be necessary to retune the detector, as may be required after the changing of frequency switch selections or after moving the detector from one installation to another, momentary operation of the RESET switch will initiate to the automatic tuning cycle. 3.6 Internal Link Selection Dual channel vehicle loop detector is 3 link positions located inside the PD230 which are used to alter the output relay configuration of the detector. The links have been placed inside the unit to avoid incorrect operation due to selection by an unauthorised operator. 4. Front Panel Indicator While the dual channel vehicle loop detector is tuning, the Channel LED will indicate the 鈥渕ode鈥?status of the detector. i) Any Channel output operating in the presence or pulse modes will come on and extinguish when the system is tuned. ii) When the AB Logic mode is selected, the Channel LEDs will alternatively flash slow and extinguish when the system is tuned. If a loop fault exists the Channel LED will come on and flash indicating a fault. If the fault is self-healing the detector will continue to operate. The channel LED will also glow whenever a vehicle is detected passing over the inductive loop. The Power LED at the top of the unit will remain on to indicate that the unit is powered. 5. INSTALLATION GUIDE Optimum functioning of the detector module is largely dependent on factors associated with the inductive sensor loop connected to it. These factors include choice of material, loop configuration and correct installation practice. A successful inductive loop vehicle detection system can be achieved bearing the following constraints in mind, and strictly following the installation instructions. The detector must be installed in a convenient weatherproof location as close as possible to the loop. 5.1 Operational Constraints Crosstalk When two loop configurations are in close proximity, the magnetic fields of one can overlap and disturb the field of the other. This phenomena, known as crosstalk, can cause false detects and detector lock-up. Crosstalk between adjacent loops operating from different detector modules can be eliminated by: 1. Careful choice of operating frequency. The closer together the two loops, the further apart the frequencies of operation must be. 2. Separation between adjacent loops. Where possible a minimum spacing of 2 metres between loops should be adhered to. 3. Careful screening of feeder cables if they are routed together with other electric cables. The screen must be earthed at the detector end only. Reinforcing The existence of reinforced steel below the road surface has the effect of reducing the inductance, and therefore the sensitivity, of the loop detection system. Hence, where reinforcing exists 2 turns should be added to the normal loop, as referred to in section 5.3. The ideal minimum spacing between the loop and the cable and steel reinforcing is 150mm, although this is not always practically possible. The slot depth should be kept as shallow as possible, taking care that the feeder remains exposed after the sealing compound has been applied. 5.2 Loop and Feeder Specification The loop and feeder should preferably constitute a single unjoined length of insulated copper conductor, with a minimum rating 15A. Joints in the loop or feeder are not recommended. Where this is not possible, joints are to be soldered and terminated in a waterproof junction box. This is extremely important for reliable detector performance. 5.3 Sensing Loop Geometry Sensing loops should, unless site conditions prohibit, be rectangular in shape and should normally be installed with the longest sides at right angle to the direction of traffic movement. These sides should ideally be 1 metre apart. The length of the loop will be determined by the width of the roadway to be monitored. The loop should reach to within 300mm of each edge of the roadway. In general, loops having a circumference measurement in excess of 10 metres should be installed using two turns of wire, while loops of less than 10 metres in circumference, should have three turns or more. Loops having a circumference measurement less than 6 metres should have four turns. It is good practice at time of installation to construct adjacent loops with alternate three and four turn windings. 5.4 Loop Installation All permanent loop installations should be installed in the roadway by cutting slots with a masonary cutting disc or similar devise. A 45掳 crosscut should be made across the loop corners to reduce the chance of damage that can be caused to the loop at right angle corners. NOMINAL SLOT WIDTH: 4mm NOMINAL SLOT DEPTH : 30mm TO 50mm A slot must also be cut from the loop circumference at one corner of the loop to the roadway edge to accommodate the feeder. A continuous loop and feeder is obtained by leaving a tail long enough to reach the detector before inserting the cable into the loop slot. Once the required number of turns of wire are wound into the slot around the loop circumference, the wire is routed again via the feeder slot to the roadway edge. A similar length is allowed to reach the detector and these two free ends are twisted together to ensure they remain in close proximity to one another. ( minimum 20 turns per metre ) Maximum recommended feeder length is 100 metres. It should be noted that the loop sensitivity decreases as the feeder length increases, so ideally thefeeder cable should be kept as short as possible. The loops are sealed using a 鈥渜uick-set鈥?black epoxy compound or hot bitumen mastic to blend with the roadway surface. 6. CONFIGURATION 6.1 PD-231 Detector CONNECTOR PIN DESIGNATION 1 Live 120V AC input 2 Neutral 卤15% 50/60 Hz 3 Channel 2 Common 4 No Use 5 Channel 1 Common 6 Channel 1 N/O 7 Channel 1 loop Twist 8 Channel 1 loop this pair 9 Channel 2 loop Twist 10 Channel 2 loop this pair 11 Channel 2 N/O 6.2 PD-232 Detector CONNECTOR PIN DESIGNATION 1 Live 230V AC input 2 Neutral 卤15% 50/60 Hz 3 Channel 2 Common 4 No Use 5 Channel 1 Common 6 Channel 1 N/O 7 Channel 1 loop Twist 8 Channel 1 loop this pair 9 Channel 2 loop Twist 10 Channel 2 loop this pair 11 Channel 2 N/O 6.3 PD-234 Detector CONNECTOR PIN DESIGNATION 1 Live 12-24V input 2 Neutral AC/DC 3 Channel 2 Common 4 No Use 5 Channel 1 Common 6 Channel 1 N/O 7 Channel 1 loop Twist 8 Channel 1 loop this pair 9 Channel 2 loop Twist 10 Channel 2 loop this pair 11 Channel 2 N/OCustomized Loop Detector website:http://www.ilead-time.com/loop-detector/