Ignition Page

The Ignition page configures the power-sequence timers on platforms that have an ignition MCU: the CQ20, CQ40, CQ40N and CQ50S series. A CQ40 that connected without its SMBus half has the page greyed out, with the reason as a tooltip (see A CQ40 with one half missing). This page covers the app itself; for what the timers do, their ranges, and the power sequence in full, see Ignition Timers.

The page reads its whole layout from the connected hardware, so what you see depends on the machine. A CQ20 shows four timers in two groups; a CQ40 or CQ40N shows five timers in three groups plus a Delay Unit card; a CQ50S shows four timers in three groups. Nothing needs configuring to switch between them.

Older models: use CQUtils for now

pcu is new, and we are still backporting support for older In-CarPC models, including ignition management. If your machine is not yet supported, use the CQUtils program preinstalled on the desktop in the meantime. Not sure which applies to your machine? Contact In-CarPC support.

The power sequence

The “Power Sequence” card at the top draws a timeline of the startup and shutdown paths, with each timer’s current value shown on the stage it controls. The stages come from the connected platform, so a CQ20 shows Ignition On to DC Power to PC Running, while a CQ40N shows a shorter Ignition On to System Start. The CQ40 and the CQ50S have no timeline, and the page opens straight on the timer cards. Select “How does the power sequence work?” underneath for an explanation written for that platform.

The full description lives on Ignition Timers.

Changing a timer

The timers are grouped into cards by what they control:

Card	Contains
Startup Sequence	The timers between turning the key and the PC booting
Shutdown Sequence	The timers between turning the key off and the PC powering down
UPS and Power Loss	The timers that apply when running on the UPS battery (CQ40, CQ40N and CQ50S)

Every timer shows its description, its Default and Range, and what happens if you set it too low or too high.

To change a timer (for example the Boot Delay on a CQ20):

1. Open the “Startup Sequence” card and find “Boot Delay”.
2. Choose a value: either a “Quick select” preset (for example “3s (default)”) or type a number into the custom value box.
3. Select “Save”.
4. In the confirmation dialog, check the value and select “Confirm”. The dialog is titled “Confirm Timer Write” and reads, for example, “Write Boot Delay = 3s?”.
5. pcu writes the value, stores it, reads it back, and shows “Set to 3s and stored” once the hardware confirms it. The current value updates to the verified reading. A CQ40N timer counted in minutes shows, for example, “Set to 5m and stored”; that MCU saves by itself, so there is no separate store step.

If pcu cannot check the timer before writing, no dialog opens and the card shows “Could not check Ignition Off Delay before writing:” followed by the reason and “Nothing was written.”

Each save re-reads the delay unit from the hardware before it checks the value, and again after you confirm. If the unit was changed outside pcu while the page was open (BIOS setup or the manufacturer’s utility), the card says so and the value is counted in the new unit. The confirmation dialog then opens with this line above the usual text, and the range message adds a matching sentence:

The delay unit has changed since this page was loaded: it was minutes and is now seconds. The value below is counted in seconds.

If you decline that dialog, the card shows “Nothing was written.” If the unit changes again while the dialog is open, nothing is written and the card shows “The delay unit changed to seconds while the confirmation was open. Nothing was written. Check the value and save again.” (the unit name matches the new unit). When the unit changed outside the page, a successful or failed save also ends with “The delay unit was changed outside this page, so the other timers may still show the old unit. Refresh the page.”

On a CQ20, if the MCU does not confirm the store, the card shows the message below instead. The value is in place but has not been stored, so save it again. See A timer was set but not stored.

Boot Delay was set to 3s but could not be stored. It will be lost when power is removed. Try saving again.

Presets and typed values are checked against the timer’s range before the write, so an out-of-range value is rejected before anything is sent to the hardware. The presets offered are the ones that suit the connected platform, so the same timer name can offer different presets on a CQ20 and a CQ40N.

Caution

Timer writes change how the vehicle PC powers up and shuts down. Confirm each value against your installation. The dialog reminds you: “MCU writes directly affect hardware power sequencing. Incorrect values may affect vehicle PC boot behavior.” The timer meanings and the defaults and ranges are covered in full on Ignition Timers. For the edge-triggered ignition behaviour, see The PC will not restart after a software shutdown.

Settings source on the CQ40 and CQ40N

Saving the Ignition Off Delay can switch the settings source

On a CQ40 or CQ40N the MCU can be taking its settings from the BIOS. Writing the Ignition Off Delay then switches the source to the MCU’s own settings, so the BIOS values stop applying. When that would happen, the “Confirm Timer Write” dialog opens with this warning above the usual question:

The MCU is currently taking its settings from the BIOS. Writing this timer will switch the settings source from BIOS to the MCU's own settings.

After the write the card adds “The settings source was switched from BIOS to the MCU’s own settings.” Cancel the dialog if you want the BIOS to keep control. The current source is the “Settings Source” row on the Home page.

Delay Unit (CQ40 and CQ40N series)

On a CQ40 or CQ40N the page shows a “Delay Unit” card above the timers. Most of that platform’s timers are counted in this unit; the Ignition On Delay is always in seconds.

The card shows the current setting as “Timers are counted in minutes” or “Timers are counted in seconds”, with “Minutes” and “Seconds” buttons to change it. It reads the setting from the hardware each time the page loads, so it stays correct even if the unit was changed outside pcu, in BIOS setup or with the manufacturer’s own utility.

Changing the unit does not convert the stored timer values

The MCU stores those timers as plain counts, so switching the unit changes what the counts mean and nothing recalculates them. A Force Off Timeout of 15 minutes becomes a 15 second timeout, which can cut power before the operating system has finished shutting down.

The app says so on the card, and the confirmation dialog (“Confirm Delay Unit Change”) repeats it before the write. After the change, re-check every timer value below.

Unit changes and timer writes cannot overlap. While the unit is being written the timer cards are disabled, and while any timer is saving the unit buttons are disabled, so the two can never race on the same MCU.

CQ50S series

A CQ50S has four timers, all counted in seconds: the Ignition On Delay in Startup Sequence, the Ignition Off Delay and Force Off Timeout in Shutdown Sequence, and the UPS Off Delay in UPS and Power Loss. The UPS Off Delay only has an effect when the optional UPS battery is fitted. There is no Delay Unit card, no Ignition Mode card and no power sequence timeline.

If the unit already holds a delay longer than pcu can set (18h 12m 15s), the Home page shows it on an extra line named after the timer, such as “Ignition Off Delay On Unit”, and saving that timer from pcu shortens it.

A CQ40 with one half missing

A CQ40 reaches its ignition timers over the SMBus and its digital I/O over port I/O, and it connects with whichever half works. If the SMBus half is missing, the Ignition page is greyed out and its tooltip gives the reason, for example:

The ignition timers are unavailable because the i2c-dev kernel module is not loaded; load it with 'sudo modprobe i2c-dev', or run 'pcu-setup.sh install' to load it at every boot.

The Digital I/O page keeps working in that state. See Install on Linux for the setup that provides the SMBus access.

Ignition mode (CQ20)

On a CQ20, an “Ignition Mode” card between the power sequence and the timer editors shows whether ignition power sequencing is currently on (“Ignition is On”) or off (“Ignition is Off”). It is read-only. The card explains the two modes: in ignition mode the MCU controls the PC’s power from the vehicle’s ignition signal; in PC mode the PC is turned on and off manually.

Ignition mode is read-only

The ignition mode is read-only on the CQ20. It is set by the physical switch on the ignition module board and cannot be changed from software. There is no toggle to enable.

Cards you do not see

The Ignition Mode and Delay Unit cards appear only on hardware that has the underlying setting. A CQ20 has an ignition mode and no delay unit; a CQ40, CQ40N or CQ50S has no ignition mode, and the CQ50S has no delay unit either. The card that does not apply is hidden rather than greyed out.

This is deliberate, and it differs from how the rest of the app behaves. Elsewhere pcu greys out an option and explains why, because the action is temporarily unavailable. A missing hardware setting is not a temporarily unavailable action, and showing a greyed-out control would imply the machine has a setting it does not have.