Originally Posted by bobsw
Has anyone tried to control a 542i by using the RS-232 controls? If so would you mind sharing one or two of the command strings with us? I am having trouble getting any response from the panel after sending RS-232 commands. Specifically, I would like to change sources using my PC and a remote keyboard and not go through the "wheel" on the remote.
I have worked enough with the RS232 protocols for the 542i to conclude that only the discrete input select seems to work (sorry, no power). Here is the format (in hex):
(example: Input 1)
50 4B H*,8
50 00 H*
I use this format with my own controller and protocol, so to translate this to something like Crestron SIMPL it would look like this:
<8 msec delay>
Where '00' (the last byte) is the input, and you would add one for each input. The most important thing I can tell you is that the delay between string one and two is critical. You need at least an 8 msec delay. The default baud rate is also 115200k.
The second most important thing is that the Olevia embedded program is flawed...it does not clear the buffer if the string is not recognized. So, if the incoming string is incorrect (or incomplete due to collision or propagation) you have appended strings that make no sense, and you must pull the AC on the unit to reset. This is not good during testing, or in a semi-permanent installation where the AC may be hard to get to (and the customer will be tremendously inconvenienced!).
I wish they would fix this in lieu of their "Future-proof" guarantee.
By the way, I do not have discrete power control so I am using a current sensor and the logic inputs on my controller in conjunction with the IR power toggle.
In conclusion, I believe the RS232 discrete input select is a bit faster (and more reliable) than the IR commands, but not by much. It would make a lot more sense to use RS232 if you had discrete power, channels, and status (i.e. feedback).