Ignition Contro Coast IPC

One of the most important and widespread uses of industrial PCs (IPCs) is for in-vehicle computing. The target environments range from automobiles to mass transit vehicles to autonomous mobile robots. While the tasks of an in-vehicle IPC system vary widely, one critical function is to provide controlled and configurable automated startup and shutdown of the compute device. 

This function ensures that startup timing of the IPC power cycle is coordinated with power distribution to other systems in the vehicle, and that shutdown of the system is executed with a coordinated closing of apps and functions to avoid the loss of data and the potential risk of system damage. This configurable, automated power management feature in IPCs is called either ignition control or ignition power control.

Fundamental Ignition Control Functions

As the name implies, the most common implementation of ignition control involves the sensing and control of a vehicle ignition signal. In automobiles and some other vehicles, this signal might be the ACC, or accessory signal, or other start signals, all of which are tied to the act of applying electrical (battery) power to the vehicle. Ignition control is implemented using a low-power microprocessor unit (MCU) that monitors the ignition signal and controls the power functions when DC input is applied to the IPC. The MCU typically uses very little power in the monitoring state with consumption at less than 2 mW.

The fundamental function of the ignition control MCU is to provide power-on and power-off delay in a controlled startup of the IPC. The typical basic operation is as follows:

  • When power is supplied to the IPC, the MCU becomes active and monitors the ignition signal.
  • When an ignition signal is sensed, the MCU starts a configurable power-on delay timer.
  • At the end of the delay, the MCU turns on standby power for the IPC and then issues a software “power start” command.
  • The IPC begins a normal boot-and-run sequence.
  • When the ignition signal becomes inactive, the MCU starts a configurable power-off delay timer.
  • At the end of this delay, the MCU issues a software power-off or shutdown command to the IPC and then turns off standby power.

The order and detail of the boot, run, and shutdown sequences relative to applications are part of the normal function and setup of the computer’s operating system and configuration of the apps and are managed separately from the ignition power control system.

Advanced Features, Configuration Options

The ignition power control system also typically provides advanced functions to further tune and manage the system power and startup/shutdown sequences. A guarded power-on/power-off feature checks for interruption in the ignition signal during either of these delays. If the ignition signal goes off during power-on delay, the MCU will return the computer to idle and not execute startup. If the ignition signal is sensed again during power-off delay, the MCU will cancel the shutdown and keep the system running. These functions ensure that the computer state matches the vehicle power state in the event of momentary or inadvertent changes. 

Other advanced functions include a system “hard-off” that ensures the completion of a power-off cycle during potential abnormal termination of an application, a related “smart” off-delay to provide power-off when an application has finished shutdown prior to the selected off delay, and even low-power battery detection.

Ignition power control systems can be configured differently depending on the IPC. In some cases, manufacturers provide a convenient rotary selector switch to toggle between multiple operating modes and related on/off delay settings. In some IPCs, the MCU can be configured through the computer bios in addition to any available selector switch. Connecting DC power (typically 12 or 24 VDC) and ignition signal (typically 12–35 VDC) to the computer is accomplished with a standard connector. In all cases be sure to refer to your IPC’s operation manual for wiring and configuration settings.

Ignition Control Operation Modes

In Nuvo-7000 industrial PCs from Neousys Technologies, for example, end users can use a rotary switch located either on the rear panel or the internal MezIO board to configure the operations mode. These systems offer 16 (0~15) operation modes with different power-on/power-off delay configurations: 

  • Mode 0: ATX mode without power-on and power-off delay. With this mode, users can only use the power button the front panel to power on or turn off the system.
  • Mode 1: AT mode without power-on and power-off delay. With this mode, the system automatically turns on when DC power is applied, and a retry mechanism repeats the power-on cycle if the system fails to boot up. 
  • Mode 2: Designed to have a very minor power on/off delay of 160ms.
  • Mode 3: Power on-delay of 10 seconds, power-off delay of 10 seconds. 
  • Mode 4: Power on-delay of 10 seconds, power-off delay of 1 minute.
  • Mode 5:  Power on-delay of 10 seconds, power-off delay of 5 minutes.
  • Mode 6: Power on-delay of 30 seconds, power-off delay of 1 minute.
  • Mode 7: Power on-delay of 30 seconds, power-off delay of 5 minutes.
  • Mode 8: Power on-delay of 30 seconds, power-off delay of 10 minutes.
  • Mode 9: Power on-delay of 3 minutes, power-off delay of 1 minute.
  • Mode 10 (A on the rotary switch): Power on-delay of 3 minutes, power-off delay of 10 minutes.
  • Mode 11 (B): Power on-delay of 3 minutes, power-off delay of 30 minutes.
  • Mode 12 (C): Power on-delay of 10 minutes, power-off delay of 30 minutes.
  • Mode 13 (D): Power on delay of 30 seconds, power-off delay of 2 hours.
  • Mode 14 (E): Power on delay of 3 minutes, power-off delay of 2 hours.
  • Mode 15 (F): Reserved for manufacturer purposes.

In addition, modes 2-15 offer a hard-off timeout of 10 minutes.

Contact Us With Questions 

Despite the term “ignition control,” this function can benefit other applications where power management may be critical to the success and reliability of IPC applications, including plant-floor edge computing for industrial automation and automation systems in other markets such as agriculture and medical devices and equipment. 

CoastIPC has the experience and expertise to help answer customer questions on ignition control and the industrial PCs that support this feature. Contact us at [email protected] or 866-412-6278 with questions.