650 System Manual (Draft)
Version 0.4 August 20, 2008
56
Theory of Operation
The J2 Health Monitor software is an application program that loads on system boot-up
and runs in the background. At a predefined interval the software reads the health
monitoring hardware and updates a set of registry keys with the current values.
Any software application can read these registry key values to check the current status of
the systems health monitoring hardware.
The registry was chosen to store the health values because different systems have
different hardware values that are monitored. By using registry keys the software
applications can just scan for the keys present to determine which values need to be
monitored for that particular hardware. One example would be the J2 650 system that
supports Intel’s Core 2 DUO processors which have two CPU temperatures where other
systems only have one. Additional registry keys are added for this second CPU core
temperature. Minimum and maximum values for some keys are also stored in the registry
so that the application can determine if a value is within J2’s specification.
It is solely up to the user’s software how to use this information. J2 makes no assumption
as to how this information is used other than to say that if the hardware health values are
within J2 specification the product is consider good. For example, people may make the
wrong assumption that higher temperatures reduce product life, however this is not the
case if the product is running within specification.
Values Monitored
Most J2 POS hardware monitors all critical system voltages, fan speed, processor and
system temperatures. The number of parameters monitored varies depending on the
system. For instance the J2 580 monitors eight voltages where the J2 650 monitors six
because the 650 only has six different voltages. Other parameters maybe monitored on
future systems.