Comments on: The VAMS-0808 matrix switcher and determining its protocol - part 2 http://www.killswtch.net/2008/03/15/the-vams-0808-matrix-switcher-and-determining-its-protocol-part-2/ A geek's thoughts on various stuff Mon, 08 Sep 2008 03:28:06 +0000 http://wordpress.org/?v=2.5.1 By: killswtch http://www.killswtch.net/2008/03/15/the-vams-0808-matrix-switcher-and-determining-its-protocol-part-2/#comment-553 killswtch Sun, 16 Mar 2008 07:41:06 +0000 http://www.killswtch.net/2008/03/15/the-vams-0808-matrix-switcher-and-determining-its-protocol-part-2/#comment-553 I can only hazard a guess that it is because of poor firmware/hardware design - perhaps the input buffer becomes temporarily locked, so any incoming data on the serial line just gets lost. Their own control software actually takes the defect into account, as it sends every command 3 times. My version works quite reliably now, but I ended up writing it using an event-driven model which wouldn't really be practical in languages that don't have notions of events. Interesting idea, using the link connector. I didn't think of that. Let's hope that method works a little more reliably. I'm going to be sticking to the standard RS232 interface though, since it works well enough to suit my needs. I can only hazard a guess that it is because of poor firmware/hardware design - perhaps the input buffer becomes temporarily locked, so any incoming data on the serial line just gets lost.

Their own control software actually takes the defect into account, as it sends every command 3 times. My version works quite reliably now, but I ended up writing it using an event-driven model which wouldn’t really be practical in languages that don’t have notions of events.

Interesting idea, using the link connector. I didn’t think of that. Let’s hope that method works a little more reliably. I’m going to be sticking to the standard RS232 interface though, since it works well enough to suit my needs.

]]> By: Larry http://www.killswtch.net/2008/03/15/the-vams-0808-matrix-switcher-and-determining-its-protocol-part-2/#comment-552 Larry Sun, 16 Mar 2008 03:24:55 +0000 http://www.killswtch.net/2008/03/15/the-vams-0808-matrix-switcher-and-determining-its-protocol-part-2/#comment-552 I enjoyed your video of the Vams and interface. I have been working on interfacing the Vams to a Symetrix Symnet 8X8 DSP unit at my job. I was interested in the fact that you have also discovered that the Vams will miss a serial command from time to time. I thought it was something I was doing wrong. It works fine about 8 out of 10 times but what I need is 100% of the time. I am surprised in the lack of documentation that the company gives in regards to the serial protocol which I derived using hyperterminal in windows. I am now concidering building and programing a small microcomputer RS232 interface using my own switching code protocol and switch the Vams using input switching pins 9 through 13 on the 15 pin link connector. The switch codes can be recorded by monitoring the output pins 1 through 5 which are open collector outputs. Pin 5 is the sync pulse and 1-4 are the data. I would be interested in finding out if you have discovered why the Vams serial interface is so unpredictable. Larry I enjoyed your video of the Vams and interface. I have been working on interfacing the Vams to a Symetrix Symnet 8X8 DSP unit at my job. I was interested in the fact that you have also discovered that the Vams will miss a serial command from time to time. I thought it was something I was doing wrong. It works fine about 8 out of 10 times but what I need is 100% of the time. I am surprised in the lack of documentation that the company gives in regards to the serial protocol which I derived using hyperterminal in windows. I am now concidering building and programing a small microcomputer RS232 interface using my own switching code protocol and switch the Vams using input switching pins 9 through 13 on the 15 pin link connector. The switch codes can be recorded by monitoring the output pins 1 through 5 which are open collector outputs. Pin 5 is the sync pulse and 1-4 are the data. I would be interested in finding out if you have discovered why the Vams serial interface is so unpredictable.

Larry

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