Komatsu 830E-AC Shop Manual page 316

Snapshots
A snapshot is a time history of real-time data that is
recorded before and after the instant that a fault code
occurs. The VHMS controller is continually recording
real-time data for various engine data items. This
allows the VHMS controller to record data for the
time period before and after a fault code occurred.
Only certain fault codes generate snapshots. When a
snapshot enabled fault code occurs, the VHMS con-
troller will record data for 330 seconds (5.5 minutes)
before the fault to 120 seconds (2 minutes) after the
fault.
In order to conserve storage memory, the VHMS
controller records snapshot data at two different
sample rates. Each data item is recorded at a rate of
one sample every 10 seconds up until 30 seconds
prior to the fault occurrence. Each data item is then
recorded at a rate of one sample per second from 30
seconds prior to 120 seconds after the fault occur-
rence.
If a snapshot enabled fault condition occurs more
than one time, the VHMS controller will record the
snapshot for the first (earliest) fault occurrence. The
only exception is the manual snapshot button, in
which case the VHMS controller will record the latest
(most recent) snapshot.
Refer to Table 3 for all the items that are recorded in
each snapshot.
D11-8
Manual Snapshots
A manual snapshot is taken by pressing the data
store button (1, Figure 11-5), located at the rear of
the center console. When the 7.5 minute snapshot is
being recorded by the VHMS controller, VHMS snap-
shot in progress light (2) will be illuminated. During
the first five minutes, the LED will be on continuously.
During the next two minutes, the LED will flash
slowly. During the last 30 seconds, the LED will flash
rapidly.
Manual snapshots are used to record current
machine data, and can then be downloaded and
stored in a laptop PC. These snapshots can be used
to observe current conditions on a machine. Over
time, these snapshots can be compared and trends
can be monitored. During the snapshot recording
period, the machine should be driven over a variety
of conditions so useful data can be collected.
FIGURE 11-5. REAR OF CENTER CONSOLE
1. Data Store Button
2. VHMS Snapshot In Progress Light
VHMS COMPONENTS D11005