Canopy 400 Series OFDM AP and SM
User Guide
Version 1, April 2008
Page 31 of 40
The Canopy 400 Series SM has a ground/Protective Earth lug, just like the AP. Although not as
critical as in the case of the AP (where there is metal-to-metal connectivity through the coax and
antenna to ground), the lug can be used to ground the SM for additional protection. Similarly, a
600SSC can be used within 3 ft (~1 m) of the SM to provide additional protection. Especially in
cases where the SM is mounted high and is more exposed, or in known difficult areas for
lightning, consider using these two techniques to increase the SM’s resistance to lightning.
Canopy 400 Series modules do not display a jitter value. Use “Received Power Level” for aiming
and then use Link Tests to confirm, similar to standard Canopy practice.
Be mindful when using the “Receive Power Level” that it is a relative, not absolute, value. The
"Receive Power Level" on a module is useful during installation to aid in aiming, where relative
values over a short period of time are of interest. However, the displayed “Receive Power Level”
is not designed to be highly accurate over time. Even if the actual received power is not varying,
the displayed "Receive Power Level" will vary with board-level temperature and may vary from
module to module. Know the limitations and use caution and judgment for any other use of
“Receive Power Levels”, including monitoring a link over time. deciding if the link is within
operating margins. deciding if a link is serviceable (link tests give a much better indication), or
comparing the link to other links.
The alignment headset will play a tone that varies in pitch (received power level), but not volume
(jitter), since Canopy 400 Series modules don’t calculate a jitter.
The Canopy 400 Series SM does not have a Spectrum Analyzer in the initial release. A standard
Canopy 5.4 GHz SM may be used to give reasonable indication of power levels across the
spectrum.
