DMI Requirements

The PwrPak7, CPT7, UIC and certain IMU enclosures are compatible with any wheel sensor meeting the following requirements:

  • Output signal duty cycle is symmetric 40% to 60%.

  • Output signal voltage is RS-422 compliant (differential).

  • The wheel sensor is powered externally. The receiver does not supply power to the wheel sensor.

  • Quadrature, pulse and direction wheel sensors are compatible.

  • Expected maximum pulse rate over measurement range does not exceed the product-dependent limit described in Table: Wheel Sensor Maximum Pulse Rates.

    Wheel Sensor Maximum Pulse Rates

    Product

    Maximum Pulse Rate

    PwrPak7

    100,000 Hz

    CPT7

    100,000 Hz

    MIC, UIC, IMU-H1900, IMU-IGM-A1, IMU-IGM-S1, IMU-ISA-100C, IMU-LN200, IMU-µIMU-IC

    300,000 Hz

    IMU with direct wheel sensor support

    See IMU documentation

An example of a compatible DMI is the Kistler Wheel Pulse Transducer CWPTA411 (WPT). See Figure: Kistler WPT.

  • A transducer traditionally fits to the outside of a non-drive wheel. A pulse is then generated from the transducer which is fed to the receiver.

  • The WPT mounts to the wheel lug nuts via adjustable mounting collets. The torsion protection rod, which maintains rotation around the wheel axis, affixes to the vehicle body with suction cups. Refer to the Kistler WPT (part number CWPTA411) user manual for mounting instructions.

    Kistler WPT

Kistler provides an M12 to DB9 cable for use with the WPT DMI. However, certain revisions of this cable do not bring through all four signal inputs. SPAN systems require at a minimum the A+ and A- signals for distance. All four signal inputs are required to measure both distance and direction correctly. See your WPT documentation for cable details.

Kistler to NovAtel Wheel Sensor Cable Connections

Kistler Cable

PwrPak7

CPT7

IMU Enclosure

IMU-FSAS

M12 Connector

All I/O Cable

IO2 Cable

M12 Connector
on NovAtel Cable

Female DB9

Pin

Signal

Wire Label

Pin on AUX 2

Pin

Wire Color

Pin

Pin 1

GND

External

Pin 8

External

External

Pin 2

+UB
(Input Power)

External

Pin 3

Signal A+

Wheel Sensor A+

Pin 14

Pin 1

White

Pin 6

Pin 4

Signal A-

Wheel Sensor A-

Pin 15

Pin 4

Yellow

Pin 7

Pin 5

Signal B+

Wheel Sensor B+

No Connection

Pin 2

Brown

Pin 3

Pin 6

Signal B-

Wheel Sensor B-

Pin 5

Grey

Pin 1

Pin 7

Reserved

No Connection

No Connection

No Connection

No Connection

Pin 8

This modification is for the Kistler WPT 8-pin M12-plug cable number 14865.

The WPT requires power to operate, which is not supplied through the receiver or IMU. Pins 1 and 2 should therefore be connected to an external power supply (+10 to +30 VDC).