Page 1 of 2

A lot of temperature probes?

Posted: Wed Apr 21, 2004 2:15 am
by masasaarnela
I have several Dallas DS18S20 temperature sensor plugged to USB. As you may know, one can connect tens of sensors to one USB-plugin.

Is it possible to connect several DS18S20

Re: A lot of temperature probes?

Posted: Wed Apr 21, 2004 2:53 am
by Johnny
[quote="masasaarnela"]I have several Dallas DS18S20 temperature sensor plugged to USB. As you may know, one can connect tens of sensors to one USB-plugin.

Is it possible to connect several DS18S20

Posted: Wed Apr 21, 2004 2:53 am
by Henry
You can connect up to 32 temp probes to the MX in TOTAL. We have included one 1-wire port on the display and all the headers are just on that one data line, so like I said, you can connect 32 in all to the display.


{edit} beat to it.. :lol:

Posted: Wed Apr 21, 2004 3:38 am
by masasaarnela
Henry wrote:You can connect up to 32 temp probes to the MX in TOTAL. We have included one 1-wire port on the display and all the headers are just on that one data line, so like I said, you can connect 32 in all to the display.


{edit} beat to it.. :lol:
Of course 32 temp probes is enough for almost everybody, even for me :D , but why to limit temp probes amount to 32? Let me quess: more probes take too much processing time?

Anyway. Thank you for your reply. That was just I wanted to know about.
:)

Posted: Wed Apr 21, 2004 4:39 pm
by Miles
In theory you can probably connect hundreds in series but of course you would have to take into account the length of transmission. The reason we said 32 is that we feel comfortable with this number and anything beyond that, your in unchartered territory. As for length, we tested 6 probes at 1 meter each with no issues but anything beyond that, your on your own. You must be aware that when data is being transmitted via a medium, the quality of the medium is very important!! :D

Posted: Wed Apr 21, 2004 11:30 pm
by masasaarnela
Miles wrote:In theory you can probably connect hundreds in series but of course you would have to take into account the length of transmission. The reason we said 32 is that we feel comfortable with this number and anything beyond that, your in unchartered territory. As for length, we tested 6 probes at 1 meter each with no issues but anything beyond that, your on your own. You must be aware that when data is being transmitted via a medium, the quality of the medium is very important!! :D
Sorry for a long quote. I have plugged together 5-6 DS18S20 (with Dallas USB-port). Some probes are near, some about 40 to 50 meters, the others are in between. I have been measuring with this combination about seven yrs now without no problems. Ok, there has been some troubles: Thunderstorms have hit nearby and so much for the probes!

I have never been in difficulties with those measuring distances and according to my opinion, results of quality have always been very good.

Of course I have not tested this combination with MX2, so I cannot say anything about this. But I trust in your words and I do not even try :roll:

If someone has tested MX2 with long distance cable I

Posted: Thu Apr 22, 2004 8:43 am
by Miles
By all means you should give it a try...I didn't mean to persuade you from trying, all that I was stating is that we have not tested the digital temperature sensors with the MX Series at such distances! :) If you do try it out, I'd be very curious to know your results!! By quality, I meant the quality of cabling, connections, etc. and not the quality of results.

Posted: Tue Apr 27, 2004 2:40 am
by masasaarnela
Miles wrote:By all means you should give it a try...I didn't mean to persuade you from trying, all that I was stating is that we have not tested the digital temperature sensors with the MX Series at such distances! :) If you do try it out, I'd be very curious to know your results!! By quality, I meant the quality of cabling, connections, etc. and not the quality of results.
I can run the test after one week because of missing WOL-plugins.

I have connected 5 DS18S20 to USB-port (Dallas DS9490) like this:

-------Ground----------|
DS18S20------ Data---- |
-------Vdd--------------|

Ground and Vdd are connected together.

MX2 seems to need all wires connected to WOL. Is it safety to connect those five DS1820

Posted: Tue Apr 27, 2004 4:42 am
by Johnny
:-?

Posted: Tue Apr 27, 2004 5:23 am
by masasaarnela
[quote="Johnny

Posted: Tue Apr 27, 2004 8:43 am
by Johnny
[quote="masasaarnela"][quote="Johnny

Posted: Tue Apr 27, 2004 8:45 am
by Miles
Are you sure you have this connected as represented in the pic?

Posted: Tue Apr 27, 2004 9:23 am
by masasaarnela
[quote="Johnny

Posted: Tue Apr 27, 2004 9:31 am
by masasaarnela
Miles wrote:Are you sure you have this connected as represented in the pic?
Hey! I like sceptical people! :D

Sure I

Posted: Tue Apr 27, 2004 2:17 pm
by masasaarnela
Miles wrote:Are you sure you have this connected as represented in the pic?
Those 5 DS18S20