Chassis dynamometer wiring and setup

Sensors wiring

First / second roller set speed sensor – Frequency input 1 / 2
Brake torque sensor – according to the drawing – Load cell input 1 – 4
When there is no constant speed ratio between dyno shaft and engine shaft and engine torque calculation is required, optional engine speed sensor can be connected to the Engine speed input.

Actuators wiring

Signal, used to control the brake on the dyno shaft, which speed is measured by Frequency input 1 is generated on Low side PWM 1 output. It is Low Side / Open Collector output with pull-up resistor to +12V. Low side PWM 2 is similarly related to Frequency input 2.

BD1 brake power supply connection

DC1 Dyno Controller terminalBD1 Brake power supply terminal
Load cell input n / –GND
Low side PWM n / SCTRL INV
Not connectedCTRL
Load cell input n / SLCOUT

Software setup

Frequency input 1(2) / Signals per rotation – signal count per rotation of first (second) roller set.
Frequency input 1(2) / Inertia – rotational inertia of first (second) roller set with all associated rotating elements. For precise measurement, inertia value entered here should include typical inertia of rotating drivetrain components. Vehicle wheels have the biggest influence here.
Frequency input 3 / Inertia should be set to 0
Load cell 1-4 / coefficient a,b – load cell calibration coefficients should be set with Wizard tool.
For unused inputs, both coefficients must be set to 0.
General/Dyno type – “chassis” option
Depending on brake type used, PWM low side output 1,2 configuration is required.

PWM output setup

Dynamometer absorber PID setup and tuning