Feedback for RTI K4 and T4

One of the problems with using an RTI remote control as the front-end for an AMX control system is the lack of feedback. With some creative thinking; HTML design; and basic HTTP knowledge, feedback can be achieved.

The RTI K4 and the soon to be released T4 both have the ability to view web sites, providing a great platform for a user interface. Lack of Java support eliminates the possibility of utilising G3 Web Control.

There will be 3 mains steps involved to get RTI control and feedback. Firstly, the GUI must be created in HTML with a standard naming convention for your buttons. I used button__<0 or 1>.jpg where button one in the OFF state would be button_1_0.jpg and button_1_1.jpg when ON. Add a hyperlink to the image that points to the NetLinx master on port 81 with an extension to allow the master to recognise the button channel. It is also wise to add a series of chars to capture the end of the hyperlink. 3 pipes work fine. The link for button 1 would look like http://192.168.0.1:81/touchpanel/button?1|||

Next create a TCP server in your NetLinx code to monitor and respond to the requests from the GUI. Remember this must be on port 81. [ip_server_open( 0:3:0, 81, 1 ) ]. Using a data_event, the button presses can now be captured by looking for the hyperlinks under the GET HTTP header. Extract the button number between the button and the ||| and convert to a number. You now have the button channel to trigger whatever events you desire.

Finally, you have to create the feedback for either this button or any others it may have triggered. Buffer the html file of the GUI and then search for the button_ or whatever naming standard you chose. If you want to turn the button ON, change the proceeding 2 chars with _1 or to turn it off use _0. Save the buffer back to the GUI file. With the HTML updated with all feedback changes, send a HTTP header redirecting (302 Found) the RTI back from port 81 to the originating html file on the master. If the page fails to refresh with the new image then you can instead redirect to another html file which contains a simple JavaScript function that attaches a random extension to the redirect. ( window.location=”/touchpanel/index.html”+”?”+Math.random()*100; ) This will cause the html to be properly refreshed every time.