Proliphix added a new series of Thermostats to their product line: the IMT350. Two models are available; the IMT350c with wired Ethernet and the IMT350w with WiFi. I won’t go into their details, the Proliphix site has all the information you need. I was lucky to receive a IMT350c a few days ago – a Domoticaforum member bought one, but since the Thermostat didn’t work in combination with the Homeseer Proliphix Plugin, it was rather useless to him; so I was asked to have a look at it. Yeah, I always like those kind of questions 
As a coincidence, some time ago I received the source code for the
Homeseer Proliphix Plugin to add Celsius support to it. The Homeseer guys are too busy with all kinds of things but not with this Plugin, so they agreed on a 3rd party (eventually being me) to add the Celsius support. Adding Celsius support had already been done, and now suddenly I had this IMT350… and i knew the Plugin didn’t work with that model, so sounds like a good opportunity to fix that problem too..
First some pics of the IMT350 (click for larger image):
Now that last one is a bit strange; do I see a USB connector there?? It sure looks like it; but since this Thermostat isn’t mine, I’ll leave the plugging in of a USB cable to the owner; I don’t want to destroy anything… I searched the manuals, but I couldn’t find any information about this USB port.
The IMT350 series Thermostats have a nice Touchscreen, which feels good and the up- and down-buttons for setting the temperatures are responsive enough. With my NT20e I sometimes had the problem that I clicked the buttons too often cause the Thermostat didn’t react fast enough; that’s gone now. The bottom row of buttons seem to react a bit slower though. Please don’t think I’m reviewing this Thermostat; I’m just telling my experiences I’ve had with it for a very short period; not long enough to be precise and conclusive. One thing surprised me was that the Thermostat takes more than 2 minutes to boot; that’s rather long, if you ask me. For the rest: this thermostat definitely looks much better compared to the NT20e, but still, I wouldn’t call this an “eye-catcher” in my house…
OK, let’s do some research on this IMT350! Connecting the Thermostat to my network was easy; the thermostat has DHCP so after connecting an Ethernet cable to the EPA-20 (Ethernet Power Adapter) and plugging the power adapter into a wall socket, I could start using the web-interface right away. I entered the factory set username and password and there it was. Time to start my own Domotica system and see if I can use this Thermostat; nope. I immediately got an exception on the first login attempt: HTTP/1.1 401 Authorization Required. Somehow I couldn’t authenticate, so I started Wireshark and looked at the conversation:
GET /get?....... HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: 192.168.10.155
Accept: text/html, */*
Accept-Encoding: identity
User-Agent: Mozilla/3.0 (compatible; Indy Library)
Authorization: Basic YCRWaS43YDRTaX4=
HTTP/1.1 401 Authorization Required
Connection: close
Date: Fri, 01 Jan 2010 01:36:20 GMT
Server: Cherokee/0.99.37 (UNIX)
WWW-Authenticate: Digest realm="proliphixrealm", nonce="0572700e162cb40274041d07e8b87252", qop="auth", algorithm="MD5"
Content-Length: 450
Content-Type: text/html
Cache-Control: no-cache
Pragma: no-cache
Aah… Digest Authentication instead of Basic… Since I’m using Borland Delphi 2005 with Indy 10, I first had to partially finish the Digest Authentication code of Indy 10, cause it didn’t work. 
After that, I could authenticate and communicate with the IMT350 just like I do with my NT20e. That’s it… all the information that I’m used to retrieve from my NT20e, came out the same way with this IMT350!
Wow, that was easy
Next step, the Homeseer Proliphix Plugin. Adding Digest Authentication to VB.NET was even simpler:
Dim wrCache As CredentialCache = New CredentialCache
Dim netCredential As NetworkCredential = New NetworkCredential(Me.User, Me.Pass)
wrCache.Add(New Uri(URL), “Digest”, netCredential)
MyWebRequest.Credentials = wrCache
Done! Launching Homeseer and configuring a new Thermostat was all that had to be done. When the Proliphix PlugIn starts up, it recognizes a potential HTTP 401 error and if this error does occur, the Plugin will retry with Digest authentication, so that both series (NT and IMT) can be supported at the same time. Here’s the result:
Homeseer Proliphix Plugin with IMT350 and NT20
The Proliphix NT20e has been in use for almost 3 years now. The Proliphix thermostat has brought me a lot of fun (integrating it into my Domotica system, working on the Homeseer Proliphix Plugin to add Celsius support) and comfort. But it’s time for a change!
http://www.partsim.com/