User’s Manual
16
AutoRec
is mainly used to record raw signals. When recording raw signals, the memory consumption
grows very rapidly with time. So in order to monitor raw signals over a long time, only short segments
can be captured at a time.
When statistics are being monitored, the instrument has enough memory to be able to record non-stop
for weeks and months. So
AutoRec
is not really necessary.
AutoRec
will capture a certain number of pre-trig samples (256 samples).
For instance
AutoRec
can be setup to:
•
Start recording a raw acceleration signal whenever the acceleration passes 0.2g.
•
Stop recording whenever the acceleration signal is < 0.2g for at least 10s.
AutoRec setup
always requires two parameters:
•
A threshold to start the recording (Acceleration or Velocity). The recording will start as soon as
the signal passes the threshold.
•
A minimum duration to stop the recording. The recording will stop after the preset duration has
elapsed with the signal staying below the threshold.
The threshold is set in
𝑚
/
𝑠
2
for accelerations, and in
𝑚
/
𝑠
for velocities.
The threshold applies to the raw signal if the instrument is set to record raw signal or signal statistics. In
that case, the threshold value
𝑇
defines a positive threshold
+
𝑇
and a negative threshold
−𝑇
. The
recording starts whenever the raw signal goes outside of the interval
[
−𝑇
, +
𝑇
]
. When measuring
acceleration signals without high-pass filter, the threshold is applied relative to the static acceleration at
the time when
AutoRec
is started. This way it is also possible to trigger a recording when the tilt of the
instrument changes by a predefined amount.
The threshold applies to the RMS level if the instrument is set to record RMS levels. In that case the
threshold value defines a positive threshold
+
𝑇
. The recording starts whenever the RMS value goes
outside of the interval
[0, +
𝑇
]
In order to trigger the recording, the signal must pass the threshold on any individual axis. For instance,
if the instrument is set to record raw velocity signals the trigger value
𝑉
represents a cube around the
origin (0,0,0), with a side-length of
2
𝑉
.
7
WiFi™
Connectivity
The
ABC Mems
supports a mode of operation where it periodically connects to a server (a Windows
PC running the
Instrument_Listener
application) through
WiFi™
. This feature is designed to let the
instrument record autonomously, periodically report the levels or signals recorded since the last
connection, and optionally send emails with RMS-level or low-battery alerts. When set, this feature will
work, even if the instrument is reset, or if it loses and regains battery power (for instance if the
instrument is reconnected to a charger after the battery has been completely drained).
This PC-server being connected-to does not have to be in the vicinity of the instrument. It can be a
continent apart, as long as it is reachable through the internet, and all firewalls have been set to allow
the connection.
The instrument connects to a
WiFi™
Router or
Access Point
that is in its vicinity. From there, it will find
the server to connect to, either by its IP address, or by its domain name.