This invention relates to instrumentation systems and more particularly to such systems in which a large operating system is used for controlling the instrumentation system and even more particularly to a system in which the power-on time is not delayed by the booting requirements of the operating system.
Instrumentation systems have increasingly started to use their own operating systems for controlling the operation of the system. This has a drawback in that portability of applications from one instrument system to another is not as straightforward as one would like due to the differences of the operating systems for the different instrument systems. One solution to this problem is to use a common operating system (OS) which will enhance the portability of applications across instrument systems. The selected OS must then be large and fully featured in order to accommodate a wide variety of applications and instrument systems. However, large OSs have relatively long start-up times which then results in a large, and unacceptable, power-on delay times.
One solution to the start-up delay problem is to store the OS in a high-speed flash memory instead of in a hard disk. The flash memory approach, while reducing the memory boot-up time, is more expensive than the hard drive approach and still suffers from some amount of start-up delay time while the OS is going through its various BIOS, memory initialization, device loading and other system checks.
An instant-on instrument system is achieved by having the operating system boot completely when power is first applied to the instrument system while the system is still in the off mode. The OS brings the instrument system to the point where all internal checks have been accomplished but does not turn on any externally detectable functions, such as the display and the display backlight at this time, the fan is running at a reduced speed, if at all. Once the OS has booted, the hard drive is stopped, the clock rate is reduced and power is removed from any measurement PC cards. At this point the instrument system is essentially in a “sleep” mode. When a user turns the instrument system on, the clock rate picks up and all other functions come alive for the duration of the user session. When the user turns the instrument system off, the system reboots and then goes into the sleep mode once again. From the user's perspective, the testing system operates essentially as in instant-on system even though it is controlled by a large operating system having an inherently long boot-up time.
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
a is a table illustrating for one embodiment the multiple states the processor subsystem may have when the power switch is on or off;
b is a table enumerating for one embodiment a typical processor subsystem transitions that occur due to toggling the power switch;
When the power switch is turned on, as determined by process 105, (meaning that it is desired to make measurements) the processor subsystem will transition from the sleep state (process 104) to the power-on state (process 114) and the clock, display, fans, and measurement subsystems will turn on, the clock will increase to its normal speed (if it had been running at a reduced speed) and the instrument is considered to be available for use almost immediately without waiting for the boot-up operation to be performed.
If the on-off instrument switch (307,
After the instrument has been in the on mode (process 114) and process 115 determines that the power switch is turned off, the processor subsystem reboots and the display, fans, measurement subsystem are turned off and the clock slowed as controlled by process 116. After reboot process 116 has finished, the processor subsystem goes into the sleep state (process 104) and the instrument is considered to be off.
It is noted that alternative embodiments may have different methods for the processor subsystem rebooting of reboot process 116, which may include, but are not limited to: a warm reboot, wherein the processor subsystem maintains power and simply restarts the OS; a cold reboot, wherein power is removed from the processor subsystem, power is restored to the processor subsystem, and the OS is started; or a combination wherein the OS is shut down, power is removed from the processor subsystem, power is restored to the processor subsystem, and the OS started.
a is a table illustrating for one embodiment the multiple states the processor subsystem may have when the power switch is on or off. While the instrument is not energized, rows 1-2, the processor subsystem remains in the no power state with the measurement subsystem and display remaining off, waiting for process 105 to signal the beginning of a new testing sequence.
If the instrument is energized with the power switch off, row 3, then the processor subsystem may be in any one of the boot, sleep, or reboot states with the measurement subsystem and display being off.
If the instrument is energized with the power switch on, row 4, then the processor subsystem may be in either the boot or operational states with the measurement subsystem and display being on.
b is a table enumerating for one embodiment typical processor subsystem transitions that may occur due to toggling the power switch. While the instrument is not energized, row 1, the previous and current power switch states do not matter; the processor subsystem will remain in the no power state, and the measurement subsystem and display will remain off.
When the instrument is energized and the processor subsystem was in the no power state (rows 2-3) the processor subsystem will transition to the boot state, and if the power switch is on (row 3) the measurement subsystem, display and any other needed systems will turn on.
When the instrument is energized and the processor subsystem was in the boot state, the power switch was off and remains off (row 4), the processor subsystem will transition to the sleep state, and the measurement subsystem and display will remain off.
When the instrument is energized and the processor subsystem was in the boot state, the power switch was on and turns off (row 5), the processor subsystem will transition to the sleep state, and the measurement subsystem and display will turn off.
When the instrument is energized and the processor subsystem was in the boot state, the power switch was off and changes to on (row 6), the processor subsystem will transition to the operational state, and the measurement subsystem and display will turn on.
When the instrument is energized and the processor subsystem was in the boot state, the power switch was on and remains on (row 7), the processor subsystem will transition to the operational state, and the measurement subsystem and display will remain on.
When the instrument is energized and the processor subsystem was in the sleep state, the power switch was off and remains off (row 8), the processor subsystem will remain in the sleep state, and the measurement subsystem and display will remain off.
When the instrument is energized and the processor subsystem was in the sleep state, the power switch was off and turns on (row 9), the processor subsystem will transition to the operational state, and the measurement subsystem and display will turn on.
When the instrument is energized and the processor subsystem was in the power on state, the power switch was on and remains on (row 10), the processor subsystem will remain in the operational state, and the measurement subsystem and display will remain on.
When the instrument is energized and the processor subsystem was in the power on state, the power switch was on and turns off (row 11), the processor subsystem will transition to the reboot state, and the measurement subsystem and display will turn off.
When the instrument is energized and the processor subsystem was in the reboot state, the power switch was off and remains off (row 12), the processor subsystem will transition to the sleep state, and the measurement subsystem and display will remain off.
When the instrument is energized and the processor subsystem was in the reboot state, the power switch was off and turns on (row 13), the processor subsystem will transition to the operational state, and the measurement subsystem and display will turn on.
Processor subsystems 301, which are controlled by processor 305 and clock 306, may have many states which may include: no power, boot, sleep, operational, and reboot. Processor subsystem 301 runs a large operating system, such as the Microsoft XP Pro operating system (OS). This OS may take as long as five minutes to boot after an “on” condition is detected, which is determined in part by the number and type of components in measurement instrument 30. In the no power state, the processor subsystem is not energized. In the boot state, the processor runs its boot process. In the sleep state the processor subsystem is energized but may not be running any active applications and may reduce its power consumption (i.e. reducing clock rates, shutting down hard drives, etc.).
In the operational state, the processor subsystem is ready for use by the measurement instrument as directed by the user. In the reboot state, the processor subsystem may run some or all of its boot process.
It is noted that processor subsystems may have many other states that may be used to either decrease the turn-on time of the instrument or to conserve power. Some processor subsystems may have multiple speed (or clock) states which may affect the power consumption of the processor subsystem. An alternative embodiment of the invention may have a low speed boot state for when the instrument is energized and the power switch is off and a high speed boot state for when the instrument is energized and the power switch is on. Similarly, there may also be high speed reboot and low speed reboot states.
It is noted that alternative embodiments may use smaller operating systems. As an example, a portable measurement instrument, such as a handheld oscilloscope may use a smaller OS to conserve power. Such an oscilloscope may have a processor subsystem boot when power is initially applied (either via batteries or an electrical outlet) and then go into a hibernation mode, wherein the state of the OS is copied to a storage device after which the processor subsystem is turned off. When the power switch is turned on, the processor subsystem copies the state of the OS from the storage device, taking less time than the boot process. When the power switch is turned off, the system may reboot and then go into hibernation mode again.