The simulator operates over the GND to Battery range. Two types of batteries are supported : 12V and 24V.
Nominal operational voltage for 12V battery is between 0 volts and 4.5-16V. Nominal operational voltage for 24V battery is between 0 volts and 16-27V
When an input is grounded by the ECU, the ECU ground voltage may be up to–1.0 to 1.5 volts as compared to the simulator's ground.
24V support
24V operation requires 24V-compatible power backplane and I/O cards. Confirm that your chassis supports 24V (indicated by a sticker on the power backplane and I/O cards) before connecting a 24V battery.