Nortech — People & Vehicle Access Solutions
3-Series Dual Channel Vehicle Detector

3-Series Dual Channel Vehicle Detector

PD230/PD231/PD232/PD234/PD239

'Compact, Flexible and Reliable'


One of the most critical components of the whole vehicle access control system

Product features & benefits

Dual channel loop detectors are used to identify the presence of vehicles by means of two independent inductive loops buried under the road and can be used in almost any application.

Detectors are available in both boxed and PCB format.

Dual channel detectors also can be used as an alternative to two single channel detectors to eliminate any presence of crosstalk.

In addition, they feature A-B logic to detect the direction of vehicles crossing the loops.

All detectors are CE tested and approved. A compact detector diagnostic unit is available for extracting data from new and existing sites.


Benefits

  • Compact size
  • Flexibility – User selectable functions
  • Diagnostic capabilities (when used with a DU100)
  • Selectable permanent presence (to eliminate premature barrier/gate closure)
  • Loop isolation protection
  • Loop frequency indication (to eliminate interference with adjacent loops)
  • Automatic sensitivity boost (ASB) – for reliable detection of high-bed vehicles (e.g. lorries)
  • A-B Logic – for different outputs depending on the vehicle direction
  • Visual fault monitor

Specifications

pd230

Self-tuning range 20-1000μH
Sensitivity 4-step selectable per channel:

High: 0.02% Δ L/L

Medium High: 0.05% Δ L/L

Medium Low: 0.1% Δ L/L

Low: 0.5% Δ L/L
Frequency 4-step adjustable, 20-70kHz (frequency determined by loop geometry)
Output configuration 1 output relays per channel (fail-safe)

Fail secure (factory option)
Pulse output duration Approx. 150ms (factory option 250ms)
Presence time Selectable: limited or permanent

Limited: presence 1 hour for 3% Δ L/L
Protection Loop isolation transformer, zener diode clamping on loop inputs and gas discharge tube protection
Power requirements 120V AC +/- 15% 48-60Hz (PD231)

230V AC +/- 15% 48-60Hz (PD232)

12-24V AC/DC +/- 15% (PD234)
Requirement 1.5VA max @ 230V
Output relays 5A @ 230V AC; N/O contact per channel (fail-safe)
Operating temp range -40 °C to +80 °C

(circuit sealed against condensation)
Material High heat ABS blend
Dimensions (mm) 76 x 40 x 78
Mounting Shelf or DIN rail socket
Connector Single rear-mount 11-pin submagnal

(86CP11)
Option 1 metre flying lead

pd239

Self-tuning range 20-1500μH
Pulse output duration Approx. 150ms
Presence time 1 hour for 3% Δ L/L permanent presence option
Power requirements 24V AC/DC +/- 15%
Requirement 1.1VA max @ 24V DC
Output relay 1A @ 230V AC; change-over contacts
Dimensions (mm) 105 x 68
Mounting Panel or plug-in
Connector Molex 14-pin female
Option Flying lead

Related documents

Datasheets, manuals and guides for the 3-Series Dual Channel Vehicle Detector. Every file is a PDF and opens in a new tab.

Directional Vehicle Detection for Complex Access Control Sites

The 3-Series Dual Channel Vehicle Detector addresses sophisticated access control requirements where single-loop detection falls short. Car parks with entry/exit monitoring, industrial facilities requiring vehicle direction tracking, and distribution centres managing two-way traffic flows benefit from the dual independent loop channels that can determine whether vehicles are entering or leaving a controlled zone.

Installation engineers specify this detector for sites where crosstalk elimination is critical—the A-B logic feature provides different outputs depending on vehicle direction, enabling accurate occupancy counting and tailgate prevention. Facilities such as airport parking structures, hospital car parks, and corporate headquarters use these detectors to integrate with counting systems and access management platforms. Available in boxed and PCB formats with voltage options spanning 110V AC to 24V DC, the detector accommodates diverse power infrastructure while the visual fault monitor provides immediate status indication for maintenance teams.

Frequently asked questions

What is A-B logic and how does it work?

A-B logic uses the sequence of loop activations to determine vehicle direction. When a vehicle crosses Loop A before Loop B, the detector outputs an A-to-B signal; crossing in reverse order outputs B-to-A. This enables counting systems to distinguish entries from exits without additional sensors.

Can the PD230 series replace two single channel detectors?

Yes. The dual channel detector provides two independent detection channels in a single unit, eliminating potential crosstalk that can occur when two separate single channel detectors operate adjacent loops. The shared frequency management ensures no interference between channels.

What output configurations are available?

The PD230 provides one fail-safe relay per channel rated at 5A @ 230V AC with N/O contacts. Outputs can be configured for presence or pulse mode, with A-B directional logic available. The PD239 PCB variant offers 1A change-over contacts suitable for low-power signalling applications.

What is the self-tuning range for the dual channel detector?

The PD230 supports 20-1000μH inductance range with 4-step adjustable frequency (20-70kHz). The PD239 extends this to 20-1500μH, accommodating larger loop configurations typical of wider vehicle entrances.

How does the detector indicate faults and status?

The faceplate provides power LED indication plus individual channel LEDs showing: tuning/flashing in A-B mode, undetect (off), detect (steady on), or fault (on with short pulse requiring manual reset). This visual feedback allows operators to quickly assess detector status without diagnostic equipment.

Case studies

3-Series Dual Channel Vehicle Detector in use

Nortech's NorParc Cuts Congestion at Sligo University Hospital

Sligo university hospital (suh) Sligo University Hospital (SUH), part of the Saolta University Health Care Group,...

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Nortech Count Management Avoids Congestion in Busy London Car Park

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The client Operated by Gloucestershire Care Services NHS Trust, Tewkesbury Community Hospital offers inpatient and...

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Product: 3-Series Dual Channel Vehicle Detector (PD230/PD231/PD232/PD234/PD239)

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