Can anyone give me any direction as to how to get started writing rs232 programs. Some of my product manuals come with programming information but I have no idea what to do with this stuff.

I'm looking for websites or books or anything really.

I know nothing about it except that it looks a lot better than sending IR codes over wires.

Also, anyone have any detailed resources concerning 1394, HAVi and firewire?

you need something to send the commands to your equipment. I use a crestron remote. The way it works is, you connect a cable between the crestron output and the unit you are controlling. then set up the touchpanel button to send the RS232 string. You could also use a computer to send a serial string but this isn't very practical. I guess there are also IR to RS232 translaters that will let you program a pronto to send a signal to trigger an RS232 command.

I'm using Via's with the new SC4 module to control equipment using the RS232 protocol.

However, Elan has not written the protocols for much of my equipment.

So, what I want to know is can I write these protocols. If I can, then how? And, is it so difficult that it would be better to just live with the IR codes?

Thanks for any help

I don't have any experience with VIA, but I would call Elan tech support. I'm sure they would be interested in having all protocols available.

RS-232 control is a very difficult area not only to understand but also to implement. One of the main problem you are going to face is the fact that there is no standard. Every manufacturer implements RS-232 their own way. Basically, if you figure out how to control a component, it does not mean you will be able to control another, even from that same manufacturer.

You will have to rely on the manufacturer of the component. If your are lucky, the manufacturer will publish their protocol in a clear format. However is often not the case. Even with everything that can go wrong with RS-232 control (i.e. no standards or poor documentation) it is, in my opinion, the best way to control your system.

ELAN and other manufacturers of control systems have RS-232 libraries of supported components already built and tested. You might want to start there.

In a nut shell... RS-232 communication really involves two parts. The first part is actually sending and receiving data. The second part involves knowing what data to send and what data to expect back.

You can think of process as placing a call to a friend. The first part is picking up the phone and dialing it. On the other side your friend has to pick up the phone.

Once the link is established, you and your friend must be able to speak and understand the same language (i.e. English, French,) and have a basic knowledge of the subject you are going to talk about. This is the part that is different for just about every component.

If you are interested, you can go to www.haguirre.com and read about ELAN’s SC-4, it is a cool product to play with.

I feel your pain mick, I have played with the sc-4 a little myself and Elan just doesn't have the P3 partners right now to make RS-232C protocols practical. If you are using yamaha you'll be fine but anything else your screwed. Also, elan just sent out version 2 for there software a couple of weeks ago so you might want to get that. As far as writing your own protocols you need to determine what baud rate and parity, bits etc.... that the manufacturer is using not to mention the string code. If you find out anything good from elan please let me know and good luck.

Ditto on the fact that understanding RS-232 for one component tells you nothing about the next one.

This also goes for manufacturer information. In the back of Vidikron manuals, one page lists ALL of the RS-232 commands in Hex for the projector. When I tried getting this kind of info from JVC for their D-ILAs, I found after lots of teeth-pulling that I had a document more than sixty pages long that told me just how they constructed their entire approach to RS-232 codes. But did not just bleep-bleep list the codes.

Xantech has just introduced a product that might cause us nightmares or be solutions here -- you can now use IR codes into this device and get RS-232 codes out. Uhh, sorry guys, we still have to figure out what the heck the RS-232 codes are supposed to be.

Thanks for all the information.

Just got back from Cedia Regional and I'm a little burnt from all the info.

I guess what I thought was I could take all the nice coding info in the back of a manual, type it in somewhere, put it somewhere, and, bang, it works.

Hector, I appreciate the comments and I know the sc4 fairly well, being a dealer as well as having been to training. I was hoping to speed along the process of getting rs232 protocols in for my products.

I guess I'll just email that guy in charge rs232 programming.

In the meantime, I'm eagerly anticipating 2 way rs232 communication.

Mick

I feel your pain with the JVC projector... Usually the best approach is the learn the language of the engineer... usually Japanese, sometimes German, so you don't get any of the errors in translation to english. Usually technical papers are not written for the consumer, so are about 8.75 times larger than they need to be. My 2 cents in writing RS-232 code... beware of timing issues. Especially units that use extensive ACK, ERR, ready, and other conditional logic. This is almost never listed in the manual (the number of seconds between valid commands and responses). Some units, like Meridian and Classe will lock up and stop functioning until cold boot if you overflow their buffers.

Almost any manufacturer will give you RS-232 documentation via email. That is how I get all of mine. Simply ask tech support for the Serial Communications Protocol (this includes baud, parity, stop / data bits, and handshaking if applicable) and Command Language (the actual interface)

For some components, it simply is as easy as sending strings such as "PON" (power on), "POF" (power off), but for other components, it is much trickier, especially when you start dealing with HEX to ASCII conversion, etc, for things such as ramping parameter adjustments.