HA7Net vs OW-SERVER

[mark_anderson_us]

Hi Guys

Just getting started with 1-wire and need to buy an interface. I'm struggling to see the difference between the HA7Net and OW-SERVER. They both seem to be 1-wire to Ethernet and support 3 x 1-wire busses. What am I missing?

Regards

Mark

[Ultrajones]

I believe both of the units support the same 1-wire sensors. The HA7Net supports 100 connected sensors and the OWServer supports only 24 connected sensors. However, the interface on the OWServer is *much* nice and it provides human readable output of the attached 1-wire sensors. In addition, the OWServer provides built in graphs and is about $80 cheaper.

I have both and prefer the OWServer. In fact, my HA7Net doesn't even have sensors connected to it anymore.

I also recommend the JB6 1-Wire Junction Box ($69) as it greatly simplifies connecting multiple sensors to the 1-Wire interface Adapters.

Regards,
Ultrajones

[Michael McSharry]

I picked up UltraJones's spare WiFi OW Server and agree that from the developers perspective it is the easiest. When all you need are a few different types (e.g. temperature, humidity) of 1 wire sensors then this is a very good way to go. In this respect it is similar to Temp08 but has an Ethernet rather than a RS-232 interface. If you have a need for more flexibility then OWAPI gives you access to just about every type of 1-wire device that is made by Dallas Semiconductor. To use this library you need something like DS9490D (USB) or DS9097U (RS-232). There are various software packages the use these equivalent interfaces. In my case I have implemented several solutions to satisfy different needs. The OWServer is in an out building so I could take advantage of the WiFi and eliminate the need to run outside underground wiring. The Temp08 is behind a IP/Serial device at a location in a different city via internet. The bulk of my devices are with cat 5 installed when the house was built and a DS9097U.

[mark_anderson_us]

I believe both of the units support the same 1-wire sensors. The HA7Net supports 100 connected sensors and the OWServer supports only 24 connected sensors. However, the interface on the OWServer is *much* nice and it provides human readable output of the attached 1-wire sensors. In addition, the OWServer provides built in graphs and is about $80 cheaper.

I have both and prefer the OWServer. In fact, my HA7Net doesn't even have sensors connected to it anymore.

I also recommend the JB6 1-Wire Junction Box ($69) as it greatly simplifies connecting multiple sensors to the 1-Wire interface Adapters.

Regards,
Ultrajones

Thanks a lot!

[mark_anderson_us]

I picked up UltraJones's spare WiFi OW Server and agree that from the developers perspective it is the easiest. When all you need are a few different types (e.g. temperature, humidity) of 1 wire sensors then this is a very good way to go. In this respect it is similar to Temp08 but has an Ethernet rather than a RS-232 interface. If you have a need for more flexibility then OWAPI gives you access to just about every type of 1-wire device that is made by Dallas Semiconductor. To use this library you need something like DS9490D (USB) or DS9097U (RS-232). There are various software packages the use these equivalent interfaces. In my case I have implemented several solutions to satisfy different needs. The OWServer is in an out building so I could take advantage of the WiFi and eliminate the need to run outside underground wiring. The Temp08 is behind a IP/Serial device at a location in a different city via internet. The bulk of my devices are with cat 5 installed when the house was built and a DS9097U.

Thanks Michael. Regarding OWAPI, i'm still imited by the specific snesors supported by the plug-in, right? For example UltraJones only supports about 5

[Michael McSharry]

If you use UltraJones plugin then you are limited to whatever he supports.

I have not tried with my OW Server, but it looks like you can use a TCP protocol that essentially gives you direct access to the 1-wire bus and then you could do all the bit level communications to manage devices. While this gives maximum flexibility, it would be low level programming and you need to understand the 1-wire device and bus protocols.

The OWAPI via DS9097U / DS9490D provides a higher level interface. With xapmcs1Wire I have implemented everything that anybody has requested except the the devices that are proprietary and not supported by OWAPI. Hobby-boards.com has introduced some of these recently.

There was a HVAC monitor that I think was sold by Hobby-Boards.com that provided a convenient access to quad A/D converter DS2450. I think it has been discontinued. Most Humidity interfaces use a DS2438 and you can use one of the channels for something like the float switch. There is a device that does sunlight with phototransitor and it could also be repurposed in a similar manner to use a different analog input than the phototransistor.

Use of RJ11 and RJ45 is common for 1-wire connections. Different companies use different pin definitions so you need to exercise caution if you mix components from different sources.

AAG and Midon Design are two other good sources for low cost 1-wire products. Dont get the AAG barometer that is interfaced with DS2406. It is a real bear to demultiplex and if my memory serves me it was 20 seconds elapsed time on the 1-wire to take a reading. Those based on DS2438 just need to do a A/D conversion of about 1 second.

There is much posted on this board about 1-wire and my general advice is that you should heavily consider the maintenance aspect of whatever you do. Devices shared on a bus could bring down the entire bus so you want to have an easy mechanism to isolate. Similarly you do not want to make a reliable network unreliable by adding devices in a topology that results in multiple reflections thus causing cancellations and distortion of the digital pulses.

[mark_anderson_us]

If you use UltraJones plugin then you are limited to whatever he supports.

I have not tried with my OW Server, but it looks like you can use a TCP protocol that essentially gives you direct access to the 1-wire bus and then you could do all the bit level communications to manage devices. While this gives maximum flexibility, it would be low level programming and you need to understand the 1-wire device and bus protocols.

The OWAPI via DS9097U / DS9490D provides a higher level interface. With xapmcs1Wire I have implemented everything that anybody has requested except the the devices that are proprietary and not supported by OWAPI. Hobby-boards.com has introduced some of these recently.

There was a HVAC monitor that I think was sold by Hobby-Boards.com that provided a convenient access to quad A/D converter DS2450. I think it has been discontinued. Most Humidity interfaces use a DS2438 and you can use one of the channels for something like the float switch. There is a device that does sunlight with phototransitor and it could also be repurposed in a similar manner to use a different analog input than the phototransistor.

Use of RJ11 and RJ45 is common for 1-wire connections. Different companies use different pin definitions so you need to exercise caution if you mix components from different sources.

AAG and Midon Design are two other good sources for low cost 1-wire products. Dont get the AAG barometer that is interfaced with DS2406. It is a real bear to demultiplex and if my memory serves me it was 20 seconds elapsed time on the 1-wire to take a reading. Those based on DS2438 just need to do a A/D conversion of about 1 second.

There is much posted on this board about 1-wire and my general advice is that you should heavily consider the maintenance aspect of whatever you do. Devices shared on a bus could bring down the entire bus so you want to have an easy mechanism to isolate. Similarly you do not want to make a reliable network unreliable by adding devices in a topology that results in multiple reflections thus causing cancellations and distortion of the digital pulses.

Thanks Michael

I want to use an existing plug-in (not interested in writing something myself).

I'm planning a fairly resilient network in a star using OW_Server and JD6. Will have 2-4 temp sensors per leg and all critical sensors will be on their leg

Regards

mark

[CharlieWayne]

Re: HA7Net vs OW-SERVER

Very interesting post above and insightful.

I'm about to start wiring some DS18B20s up to my GEM. I bought the sensors of ebay and they came with a pigtail that I can crimp a RJ45 onto.

For the bus its my intent to use CAT5e with splitters at each sensor leg. I found and bought these splitters at monoprice. http://www.monoprice.com/Product?c_i...seq=1&format=2

With these splitters, I figured that in the event of sensor failure or the need for diag it would provide an easy method to unplug each sensor yet still allow pass through to others down the bus.

Like the ideas of the ability to use analog inputs like mike and mildon discussed. Question is how would you convert analog signal voltages into measurable values (pressure psi, position %, temp f or c, or what ever analog sensor design).





CharlieWayne

[Michael McSharry]

If you are running cat5 then you will likely find it easier to make connections onto the wire with standard jacks such as http://www.monoprice.com/Category?c_id=105&cp_id=10513.

Recognize that the pigtails you are connecting each represent a length of wire that will degrade the signals from the distribution point. While a T topology is the most convenient for most to implement, it is also the one that is most problematic.

When you design your wiring then make a conscience decision on how you are going to handle power distribution to devices that may be connected. 5VDC and 12VDC are commonly used levels with circuits using 1-wire devices. Wire has resistance so 12VDC at one end may not be 12VDC at the circuit.

The conversion of voltage to more convenient units is done in software. xapmcs1wire does various conversions for the circuits that I or others have interfaced with it. The user then selects the ones of interest and ignores the others. Humidity percentage is so widely done with Honeywell sensor that it is available with just about every software package that interfaces 1-wire. At the user level you can also run scripts that populate virtual devices based upon an input that is in terms of voltage.