ERL tesla lite, User Manual, Page: 84 / 288

8 Configuring the Recorder
8-6 TESLA LITE User Manual D03283R01.10
speed fault records and used to display calculated high speed channels. The
sample rate does not affect the data rate of “downstream” calculations that gen-
erate data for low speed swing recordings, low speed calculated channels, the
metering display update rate or the trending rate.
The Sample Rate also determines the frequency response of the front-end anti-
aliasing filters and therefore the bandwith of the analog channels. See the fol-
lowing tables.
TESLA LITE sample rate is 96 samples per cycle (5760 samples per second in
a 60 hz frequncy system or 4800 samples per second for 50 Hz frequency). It
can calculate upto the 25th Harmonic at this sample rate.
Comments
In the Comments section you can enter a description of the configuration for
reference purposes. This description is also displayed in the configuration
management screen to identify saved configuration files.
Chatter Limits
The Limits screen, accessed by expanding the Identification branch in the Nav-
igation tree, lets you define how the recorder behaves when dealing with nu-
merous, repetitive triggers.
The chatter limit settings specify the time window ( Chatter Detection Window)
in which the chatter detector works. The detector limits the number of triggers
that can occur - on the same channel and of the same trigger type -within the
window. Four External Input triggers and two analog or calculated channel
triggers are allowed in the window. If this number is exceeded, the trigger is
automatically disabled until the trigger rate falls to less than that number for
the specified number of seconds (
Recovery Time) . This prevents the recorder
from being overloaded by triggers and automatically re-enables the trigger
when conditions return to normal.
Note: Although an External Input triggers may be disabled by a chatter limit
function, the recording will contain the original External Input data.
8.4 TESLA Alarms
The TESLA Alarms screen, accessed by expanding the Identification branch
in the Navigation tree, lets you select the output contact to be closed when the
memory for triggered records or long term trend logs is nearly full or Time
Sync is lost is detected. The accumulation mode (recycle of stop-when-full)
and the level at which to alarm are set in the Recording tab of the Utilities
screen (“Recording Control Settings” on page 7-5). These alarm condition can
also be accessed via the SCADA protocols.