In most situations, you want people – farmers, on-farm contractors and tractor drivers – to be able to see their Plexus radios from a good way off. This avoids destroying them with machinery. It probably doesn’t do the machinery any good and Plexus replacements aren’t free. Nor do I imagine that anyone really wants to find bits of plastic and circuit-board in their prized harvest. So our engineers went to a bit of trouble to make our Plexus radio units the opposite of invisible. From the bright chilli-red base of the housing to the reflective strips on the support poles, the aim has been to ensure that the radios stand out.
The high visibility that is an asset in a vineyard or olive plantation turns out to be a liability on a racecourse; it distracts the horses. So the good folk at the Melbourne Racing Club asked that a more discreet Plexus network was be installed at Caulfield Racecourse to monitor track conditions.
Tim Brown from MSAS (one of MEA’s agents in Victoria) took the issue seriously - and figured out how to arrange nine Plexus field stations around the track without drawing themselves to the attention of the horses.
Some thought was given to spraying the radio bases and support poles an attractive primer-grey, but this was abandoned in favour of situating some of the field stations really, really low. How low? Installed height for some of the Stations is a mere 0.5m. That’s an issue because, as a rule of thumb, the higher the radios are above ground, the better the network performs. We usually stick them up around two and a half to three metres above ground and twice as high again in tree crops. But at Caulfield the requirement was ‘out of sight, out of equine mind’, so down near the turf they went.
At first, two of the nine stations were unable to connect to the network. The ones at the 500m and 800m mark as it happens. Nothing significant about those numbers, but I know some of you would want to know. With the sensors (short EnviroPro probes measuring moisture, temperature and salinity) installed under the track itself, moving the stations was going to be a Big Deal.
The answer to the problem was ultimately the same as the problem it answered: height. As a venerable Middle Eastern saying has it, “If the field stations cannot come to the hub, then the hub must go to the field stations”. The Plexus hub was installed on the fascia of a two-story building in the middle of the track. Including the standard support hardware, this places the hub around nine metres above ground level. Plexus field stations can work from ground level provided there is a through-the-air path upwards to the hub. Did it work? You bet.
|A Plexus Field Station peeks out of its enclosure at the Caulfield Racecourse.|