Logging Tip For Newer Laptops

Hi All,

I have a bit of a tip for those that have newer laptops and use them for logging. In particular the HP / Compaq brand but I'm sure other brands will be effected the same way.

Some time ago HP started releasing their laptops with a new feature called "HP Drive Guard". The basic idea of this is as follows...

Quote:

HP 3D DriveGuard protects the hard drive by parking the drive and halting I/O requests under either of
the following conditions:
● You drop the computer.
● You move the computer with the display closed while the computer is running on battery power.
A short time after the end of one of these events, HP 3D DriveGuard returns the hard drive to normal
operation.

They way it does this is that the laptop has an inbuilt accelerometer in it that senses when the laptop is about to suffer a mechanical shock. It then parks the hard drive heads to protect the disk.

So what does this have to do with logging? Well many will run their laptops on battery power while logging in the car. Many will also close the lid of the laptop to turn off the screen, saving power and making the battery power last much longer. The problem with these newer laptops is that the motion of the car will activate the HDD protection system, halting all I/O to the HDD. This will cause the ScanTool to freeze and all data will be lost during this time. Attached is an attempt at a 15minute log, but with the lid of the laptop closed. If you look at it, you will see it's rather short.......

If you have been having random problems with missing data in log files and you tend to log with the lid of the laptop shut, check the specs of your laptop for something like the HP drive Guard function. There are a few ways of getting past this issue though.

Leave the lid of the laptop open, but set a black screen saver to kick in fairly fast to save power.
Load the HD Guard software and disable the function while logging.

Simon.