Command and Control for the Presentation Recorders

A question that comes up frequently is “Can I control your unit via RS-232?”. So in this post I’d like to go over the command and control options for the Presentation Recorder line.

There are four control interfaces to the Presentation Recorders:

  • An interactive web page
  • Serial RS-232 commands
  • Serial commands over IP telnet
  • A Web 2.0 REST API interface

The interactive web page (the “Quick Start” page) is a simple to use control page that makes it easy to start and stop a recording or streaming session. However, giving ordinary (untrained) users the administrative password to use this page can be dangerous because they can really destroy the setup of the box if they don’t know what they’re doing. There is a reduced-privilege coordinator login that can limit the damage, but for most installations the web page is not used for day-to-day control.

A large majority of our installations use Serial RS-232 commands in conjunction with some type of controller, typically a Crestron or AMX. The command set is very rich and covers nearly every aspect of operation of the unit with detailed status conditions available for feedback. Even so, starting and stopping a recording or streaming session can be done with just a few lines of code.

A related technique is to use these same serial commands over an internet telnet-protocol session. Some controllers have this option and NCast has example Java code which can be used to control the recorders from a desktop or laptop. With this method an existing PC in an auditorium can be programmed to do full recorder control.

Finally, a new REST API has been introduced. This method is extremely useful for web page programmers who are familiar with Web 2.0 technologies such as Ajax or jQuery. With the REST interface simple web pages can be customized for instructor control of the units or for monitoring the status and activity of multiple units deployed on the campus.

Please contact Technical Support if you have additional questions about command and control.

17. July 2014 by Hank Magnuski
Categories: Manuals, Presentation Recorders | Tags: , , | Comments Off on Command and Control for the Presentation Recorders