How reliable is 1wire please?

[Derek Prior]

I am in the UK and considering installing a 1wire TEMP08 subsystem with my HSPRO set up. I need to measure about 10 temperatures, mainly central heating pipes and the hot water tank, not air temperatures. I would like to get the temperatures into HSPRO devices. I would have to install the 3 cable runs close to existing mains wiring though, would that be a problem? Would I be likely to get interference or unreliable runs? What would be teh best way of ordering the TEMP08 plus 10 sensors here in the UK?

Thanks for your help. Any idea how many others are doimng this?

[Rupp]

My Temp05 has been measuring temps for over 10 years without one hiccup. Initial setup was a bit of a challenge but once I added a few resistors it's been flawless since. So it may take a bit of work at first but once setup they simply work.

[jon00]

You will probably have to order the TEMP08 direct from Midon Design. They used to be able to distribute from mainland Europe but Mitch (Midon) would have to confirm.

You can get DS18S20 from here in the UK.

As for runs, I have several 1-wire cables running parallel with mains without issue. You need to be careful how it is connected and you can look at my one-wire guide here.

[nightwalker]

I've been running a Temp08 for about 3 years now. I use it with the BL1Wire Plug-in and 15 temp sensors. It hasn't missed a beat.

[Michael McSharry]

As most have alluded to above the issue is usually not one of failure after it has been running, but getting it running reliably. The wiring topology has a lot to do with you chance of success. The less you stray from design recommendation the better your chances of initial success will be and then in a year to two to add something else without bring down a previously working system.

The interface to the computer is not as significant as the quality of the 1-wire network. A Temp08 is a good interface choice for something you want to install and forget. This assume it supports the suite of sensors that you want to use. There is no firmware download available to allow easy upgrades in the future.

The Temp08 uses a simple ascii serial protocol for communications and there are many software solutions that talk with HS and Temp08 available. I have two. UltraJones has one. Blade has one. I think Jim Doolittle's is still available. There are many DS9097U software solutions as well. I have two. I believe Steve Anderson has one. There are many non-HS solutions as well for DS9097U as this is the interface supported by the 1-wire manufacturer.

If you are active with playing with new sensors and types of sensors then a more flexible solution such as the DS9097U or DS9490D will be a preferred interface. If you would like to have direct LAN connectivity then the interface from Embedded Data System and the UltraJones plugin would be a good choice. Again the sensor types are limited with the EDS approach.

In my years with 1-wire I have had one failure that I would attribute to the equipment. It was a DS2409 switch in a 1-wire hub. I have had connector issues where I tried to use RJ45/RJ11 in an unconditioned space and they eventually decayed. I have also had three failures of light/solar sensor which I attribute to design rather than equipment failure. Before I started using 1-wire hub to isolate branches of a home run topology I was suseptable to wire length. I tried to "clean up" some wiring, but making the wire shorter caused communications problems so I restored the original wiring.

The bottom line is that 1-wire is reliable if you have a reliable installer.

[Midon]

I am in the UK and considering installing a 1wire TEMP08 subsystem with my HSPRO set up. I need to measure about 10 temperatures, mainly central heating pipes and the hot water tank, not air temperatures. I would like to get the temperatures into HSPRO devices. I would have to install the 3 cable runs close to existing mains wiring though, would that be a problem? Would I be likely to get interference or unreliable runs? What would be teh best way of ordering the TEMP08 plus 10 sensors here in the UK?

Thanks for your help. Any idea how many others are doimng this?

Derek,

Run any cable perpindicular to mains wiring as a precaution. Other than that, what Rupp and Michael say is absolutely true - once the system is up and running, you should enjoy reliable operation.

I'd recommend some reading about 1-Wire practices, such as our guide at this link. There are other resources on the internet as well.

We ship globally and have many installations in service in the UK.

Mitch

[NicolaiL]

Derek, I'm in the UK as well and have had a large 1-wire network. However as I also had a number of Oregon Scientific sensors I have now, for no other reasons than minimising complexity, retired my redundant 1-wire network.

If you are not adverse to second hand kit I'm sure we could come to some sort of arrangement.

You can reach me at nicolai at landschultz dot co dot uk if this has any interest.

[mrhappy]

You can also get DS18S20's from here for a bit cheaper, http://www.sheepwalkelectronics.co.u...mponents.shtml - I ordered from there and have no complaints. They will also make you a custom cable with a DS18S20 on it if you want it aswell.

[Guest]

Have got a few of these connected DS18B20

[Pete]

My 1-Wire has been stable over 10 years now. I have expanded it as I already had run much cat5e everywhere. Thus I have multiple 1-wire devices each with their own sensors. (Temp08 X2, Temp05, 9097S (maxim X3) and a newer one which is not Maxim but is USB (and it is seen as a USB to Serial device by the OS). Recently endeavor was switching the temperature sensors to combo temperature and humidity sensors. This was though with a mix of AAG, Midon and HB sensors. I had multiple combo temperature, humidity and light sensors in place. One actually ran for years. A couple of years ago it failed; I replaced and added more combos. The ones easiest to replace (ground level) continue to work fine. The one and only one in the roof pagodo two stories up failed after about two months of running; I have not replaced it. My two AAG anemometers have always both over reported wind speeds via the Temp08 / 05 connections. Folks would write to me about the close to 80Mph winds that my AAG was posting on WUN. I have since then put two more "test" non 1-wire anemometers up. One being the "fine offset" weather station and the other being a Davis Vantage Vue weather station. This both are reporting seemingly normal wind speeds.

That said though I still have both parasitic and non parasitic 1-wire networks and both star and "linear" topology 1-wire networks running today. All working just fine for me.

[Jakob.Sand]

Hi experts!

Can ask a 1-wire question too?
I need to find a cheap and distributed way to control output relays and recieve status from digtial inputs. I live in a farm so distances of up to 500m are needed. Can 1-wire handle this?
And is 1-wire suitable for IO control too? How about speed ? Ie. How fast will I be able to messearue changes on the input?

Can anybody recommend a IO board if relevant?

[Michael McSharry]

The distance is too great for a direct 1-wire connection, but you can still use 1-wire or other options to connect sensors and then a different transport back to your central site. A solution such as WebControl for $35 can handle 8 temperature sensors and internet or LAN can be used to communicate the temperature readings. It has humidity, 8 digital input and 8 digital output as well.

Another concept is a RS-232 adapter such as IP/232 and a Temp08. Another is the Embedded Data Systems product HA7Net which is also a LAN connection without an adapter.

[Midon]

Hi experts!

Can ask a 1-wire question too?
I need to find a cheap and distributed way to control output relays and recieve status from digtial inputs. I live in a farm so distances of up to 500m are needed. Can 1-wire handle this?
And is 1-wire suitable for IO control too? How about speed ? Ie. How fast will I be able to messearue changes on the input?

Can anybody recommend a IO board if relevant?

1-Wire can handle the measurement and control aspects. Use the proper sensors; Ds2406 or DS2408 for output or input.

The distance is a concern. 1-Wire beyond 100m is not recommended. Also, running 1-Wire any large distance outdoors would raise concerns about protection against lightning.

If you are trying to control/sense from one remote point to a central location, then use a local 1-Wire controller at the remote point and send the information back to the central point via some other means (fibre perhaps?). If you have multiple remote points to monitor/control perhaps a different method might be more practical.

Mitch

[Bestgear]

Thanks for your help. Any idea how many others are doimng this?

I am in the UK, and until fairly receintly, had a pretty big 1-wire network.

I think it was Michael that said, you can lash it up and it works just fine, or you can follow the rule book and get nothing but trouble....

I ended up using two 1-wire switches - and that made it all reliable and tried to keep the number of devices per "leg" to no more than three or four.

I used temp sensors on the heating system and hot water tank etc... they worked fine... had a thermometer in every room too.

Where I got annoyed with it was when devices would dissapear for no (apparent) reason - but having said that, plan well, an duse a switch and all should be well.

What PC interface are you going to use? The DS9490 and serial equivalent work well for next to no cost.


David

[Pete]

Here I have multiple 1-wire networks using mutliple topologies for many years now. I have Temp05, 2 Temp08-s and about 4 9097's parasitic and non parasitic networks. I am using category 5e cabling for all of it. I used patch panels many years ago to wire up the runs and currently they are configured in a star or linear topology.

Works for me. I do keep addressing, devices, physical locations and wires documented both hand written and typed out.