HP Forums
How many calculators can be connected in a classroom? - Printable Version

+- HP Forums (https://www.hpmuseum.org/forum)
+-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html)
+--- Forum: HP Prime (/forum-5.html)
+--- Thread: How many calculators can be connected in a classroom? (/thread-14049.html)



How many calculators can be connected in a classroom? - StephenG1CMZ - 11-25-2019 09:10 AM

I'm just curious...
I'm sure the limit used to be 30 calculators - I remember thinking you'd need two networks, given the typical 33* pupils in a UK classroom when I was at school.

In this thread Tim mentions 60 in passing (but is it conceivable that is a test of the WiFi loading of two networks, not what a single network can handle? ).
https://www.hpmuseum.org/forum/thread-6135.html?highlight=Number+of+calculators

In another thread, Cyrille mentions 40 calculators.
https://www.hpmuseum.org/forum/thread-14042.html

So, has the old limit of 30 calculators been upgraded?

*Recent statistics are unclear. I have seen reference to a legal limit of 30, but also to statistics and news reports higher (up to 46 for maths classes
https://www.google.com/amp/s/www.bbc.co.uk/news/amp/uk-england-38506305).


RE: How many calculators can be connected in a classroom? - Tim Wessman - 11-25-2019 09:42 AM

There is no enforced limit. Multiple antennas can be connected at once and they are comboned. of course, the more devices you have the more have to share the limited bandwidth.

In China it is common to use two antennas, with a long USB cable to put the second back father n the room. They tend to have long skinny classrooms.


RE: How many calculators can be connected in a classroom? - yangyongkang - 11-25-2019 12:13 PM

(11-25-2019 09:42 AM)Tim Wessman Wrote:  In China it is common to use two antennas, with a long USB cable to put the second back father n the room. They tend to have long skinny classrooms.

As a Chinese, this sentence seems a bit too real. But what do you mean by China Taiwan or China?


RE: How many calculators can be connected in a classroom? - cyrille de brébisson - 11-26-2019 06:15 AM

Hello,

There is a hard limit of 254 calculators per antennae, This is imposed by the protocol... However, with around 20ms "on air time" slots per calculator, this means that a calculator will be able to send only 1 burst (around 900 bytes) every 5s... Which will not be a good user experience! And this is hoping that all goes well...

There is however NO limits to the number of antennae attached to a single computer, so there is no limits to the number of calculators that could be attached to a single computer, besides the computers memory, so this will be quite resource intensive.

Cyrille