Actiwave User Guide - Issue 2.0.18
Page 32
11 FAQ & Troubleshooting
What limits the
memory size?
Large flash memories are very power hungry. Erasing and
writing a large memory array would severely affect the battery
life. Writing to the memories is the main source of battery drain
even with the low power serial flash we use.
What limits the
download speed?
In order to keep the power consumption to a minimum a low
power low speed processor is required. It cannot send data any
faster than this. The download and saving of the data to disc
also takes considerable time even on a fast PC.
Is data compression
used?
No. Data compression takes a lot of processing power and no
algorithm is able to guarantee 100% true reproduction of the
waveform whilst compressing. This means that depending on
the choice of algorithm, either the waveform could be altered in
an unpredictable manner, or the device may not record for as
long as the user is expecting. We do not know the users
application so we do not wish to lower the integrity of the data.
Data compression algorithms always need to be applied with
care taking into account the intended analysis methods.
Why do the first few
seconds sometimes
show a DC offset
To conserve power the Actiwave unit powers down during the
start delay. When it powers up to start storing data the
amplifiers need a few seconds to settle.
How synchronous
are the channels?
The waveforms on one unit are all recorded within a hundred
microseconds. The variation between units is less than 0.5
seconds when set up, although larger drift may occur over a long
recording.
The Actiwave Dock
is not recognised or
will not
communicate:
The most likely cause of problems will be due to the USB
drivers. Windows will sometimes automatically try to choose the
wrong driver during installation or may in some other way fail to
install the drivers correctly. See Appendix A for advice on
installing the USB drivers manually.
The software offers
to update the
Actiwave firmware
–
what does this
mean?
The Actiwave Software is shipped with the latest device
operating firmware. If the software detects that any Actiwave has
older firmware, it will inform you that an update is available. It is
recommended that firmware updates are applied to ensure that
you benefit any improvements to the device. Follow the on-
