Truck Unit

The Truck Unit has these components:

Operators Display Panel
12 key Keypad
Control Unit (Trucks' Computer)
Optional Radio Unit
Cables to interconnect these components

Control Unit

The trucks computer is a 32bit microcontroller which was designed specifically for engine control on high performance motor vehicles. Some of this functionality has been utilised, and some is available for future enhancement.

Power Supply

The power supply operates over the range of 12-100 volts. There is no requirement for any jumpers or straps. The unit is fully protected against reverse connection and has excellent electrical noise immunity.

Drivers Display

The drivers LCD has the following features:

16 characters by 1 line
Character size is 4.8 mm wide x 8 mm high.
Backlight (green).

Clock & Calendar

The clock & calendar function is implemented using a battery backed up real time clock, which keeps the time in seconds, minutes, hours, days, months and years. The calendar is year 2000 compliant. The date & time is adjusted (for daylight saving etc) by the Base Station computer when a data transfer is done.

System Inputs

Analog Inputs (13 off)

Thirteen inputs are software configurable where inputs may be used as digital inputs, analog inputs or TPU (Time Processing Unit) inputs. Any combination of these is allowed. Digital inputs are suitable for measuring things like selected gear, forward movement, reverse movement, lift and lower, light or other switches (ie, are they on ?) Analog inputs are used for measuring things like water temperature, oil pressure, weight. The input range is between 0 – 90V. Eight of these inputs are also able to be inverted, where negative logic is used.

Battery Sense Input

This input is used to sense the trucks battery voltage, especially useful on battery electric trucks.

Time Processor Inputs (eight off)

The Time Processor Unit (TPU) is a computer in its own right, and is specifically designed for measuring time and counting pulses. This means that the Fleet Assist™ unit can accurately measure the trucks’ speed, its engine rpm, the height of the forks and any other lineal or time domained quantity. The input range is 0-12V.

Shock Monitor Inputs (up to 4 off)

Up to four accelerometers can be wired to the Control Unit. They record acceleration peaks, which indicate vehicle shock due to impact for example. These inputs detect the amplitude peak of the input signal and hold it until the sample is has been read. The hold is then released.

Noise suppression on Inputs

Filtering is provided to reduce received radio frequency noise on all inputs. This filtering is implemented as an RC low pass first order filter with a transfer function zero at 1000Hz. This determines the measurement accuracy when measuring changing signals. The error is due to lag in the filter. Higher bandwidths provide less filtering but improved accuracy when sampling dynamic signals. For a resolution of 10 bits, a settling time of 6.93 time constants is required between samples. t = 1/ (2 p F) The conversion time is less than 21 uS. This corresponds to 1/7.6 timeconstants.

System Outputs

Relay Output

An internal relay controls a slave relay which enables the truck to drive. This relay has normally open contacts which close under software control after the driver's PIN code has been validated.

Open Collector Outputs

Seven open collector outputs are provided. These outputs can be used to activate external indicators and/or relays. The activation of these outputs is under full software control where these can be activated depending on the state of inputs and may be time delayed.

Power Failure Protection

When the power starts to fail the CPU will run long enough to complete operations and prepare for power loss to the CPU and memory, thus preparing for resumption of normal operation as soon as power resumes. There is no loss of data.

Internal Battery backup

The clock and memory in the Control Unit is kept alive with a battery. The level of this battery is monitored by the CPU. Charging is achieved using a technique that reduces ‘memory effect’ and allows the battery to be recharged from any point in the discharge cycle. The unit will hold memory for up to twelve without losing data.

Environmental Protection

The modules are sealed to IP65.

Standard unit

All casings are made in high quality stainless steel

Main Processor unit (dimensions : 135 x 165 x 40, weight 1Kg)
Display unit (dimensions : 52 x 150 x 65, weight 0.5Kg)
12 key keypad – Industrial
Single axis shock monitor
Cable for connecting the display unit, main processor and keyboard (3M)
Pre loaded control software

(logged data and drivers details are transferred to the PC via cable)

Software (Windows PC)

PC control and analysis software is provided on a CD. One copy per site is supplied.

Optional add-ons, ordered with units

Cable harness, power relay
Speed / RPM sensors
Truck mounted radio (+2M cable)
Radio base station (+10M cable, RS232 / RS422), 2000M cable length possible with RS422.
Ethernet interconnection for multiple radio base stations
Heavy duty stainless steel ‘vandal proof’ keypad
Shock monitor single axis, to 25g’s (+2M cable)
Shock monitor dual axis, to 25g’s (+2M cable)
All other options depend on truck model etc