Colin we might be in competition...where do you stand on the issue of IP?
We must be in parallel universes; amongst other things we are also developing "arrays of massive numbers" of "near-field" Readers for cattle feed-lots. Here the beasts are confined and feed regularly from a trough which is filled daily by a huge truck which decants "special grow fast food mixtures"...
Like your cows, they hear the truck coming , salivate and rush over in anticipation of lush feed and er...er..hormones...etc.
Our concept uses the existing HDX ear tags they arrive with (feed-lots are like a holiday resort for them)...next stop, er...er...the golden arches...
We are developing a plastic mould/embedded retro-fit "Feed-Trough Lip Reader"...as with you, about 600mm apart, and yes when they arrive
or are "inducted" ... they are skinny and 100 days later they are fat... consequently, how many bovine can dine side by side is a issue, but is
solvable.
Our strategy is to multiplex, and while there may be <100 beasts per pen and then >50 pens... so scanning 5000 readers (assuming our
client can afford such a thing) one at a time as in a massive multiplexer will take time...to speed things up we propose to interleave the
multiplexing say repeat it every 10 adjacent reader.
Unlike your task to open the feed door to a "qualified animal" (my understanding)...we will send the UniqueAnimalCode back to a remote
remote host...here it is time stamped and put into a form of ExcelSpreadSheet...several things are deduced from the "clever in the
spreadsheet"...how many minutes each beast had his/her head in the feed trough (food intake by inference) and if a beast is repeatedly
arriving "at the end" of the cue/trough then this is a sick cow (take him off to the house vet)...etc
Colin, we use the RFID EarTag as a pointer to a row/column in a spreadsheet, wherein can also reside each beasts total history, eye colour
and inside leg measurement if you so desire...it may be worth your while reflecting on this mechanism, and then sending back an "open door" command?
As I understand it, you have a "house-brick" sized box around each cow's neck...do they still retain an RFID Eartag or do you cut it out?
I am still a little unsure of your use of the term "co-existing" how do the untagged cows get to eat if they cannot open a door?
In America/Canada we had issues with "co-mingelling" of animals... where in the herd were a mixture of FDX and HDX Tags...here it was
necessary to have a reader that could read both...ISO allows for this but we have drawn a line in the sand..."it's over red-rover",
Australia has decided on HDX... the rest of the world is still playing dice!
Your use of "random" is creative ... we do some thing similar as part of our concept of "dynamic adaptation"...I think I might buy a ticket
in that lottery you are running.
Tarry a while yet, and we can future get down to the how's... but first the why's. You will agree the question is far more interesting than the answer?
Regards
Ray