Does anyone know of a good source for educational material for RS-232. It's time I started to learn more about it. Any suggestions?

One suggestion is:

Get an RS-232 device (any Integra receiver...a good choice because it has alot of two way commands) and use your Windows Terminal program if you don't have A/V software & hardware.

Integra posts all their protocols on their website.

Learn the HARD way, then you'll really know it!

I put aside my article on serial signals for the Yahoo forum. Maybe it's time I finished it. An impromtu vote: how many would find a primer on serial communication useful? It will NOT include as a subject how to build a string in either Crestron nor AMX's programming language but is a theorectical piece on protocol interpretation, binary, hex, decimal and ASCII, who computers "see" strings, how terminal emulation programs display string values. What stopped me was some of the research. I felt the need to footnote and that has taken more time then I thought necessary. Then again, other than the Yahoo site where would one post such an article?

Alan

Why do I get the Feeling "Integration Pros" is about to be brought up by someone...


Feel free to pick my brain and have me check into some stuff for ya Alan... Could be very usefull for some folks... I might even learn a thing or 2

Stew Pidasso,

Many people forget about this resource, but... try your local public library. Don't get one book, get 3 or 4. Read what you need from each of them. They'll each approach the problem from different directions, some of which you will relate to better than others.

I would search based on "Serial Protocol", "RS232", and if your Hex / Binary skills are not real good, look for something on this as well. If you can look at: 10011010 and know this is 9A hex, and can compute the decimal value as well, no need for the Hex / Binary brush up.

I would really like a "guide" on the basics. I really want to goto crestron training but I need to get the fundamentals of programming down before I blow the cash for manufacturer specific training. I bought some books on JAVA and Visual Basic and I have VB Studio. I also downloaded some crestron pdf's, about 1000 pages worth. The problem is that I have these resources, but I have no clue where to start. any help would be greatly appreciated.

Later
Matt

If you are an RTI dealer. I strongly suggest getting a T2+, RP6 and CM232 from them. You'll be up and running in no time. Its not difficult once you get some basics. If you are RTI dealer, they have added a new pdf in the dealer site with basic knowledge....

Go for it Alan...IF you have the time.

First there is RS-232 protocol, which includes both the physical wiring of the device and the electronic arbitration method. Most programmers have very little need to know the finer details of how the transmitter and receiver devices actually actuate, buffer, mux, demux, etc... other than know baud, parity, start bits, stop bits, hardware or software flow control. This whole list of protocol parameters might look something like 9600bps8n1 in a typical manual. There should also be a reference to how the device is wired. One of the deviations from standard has been the adoption of this cute little 9 pin connector, for some reason people feel that they don't have to follow the standard 25 pin fitting, I guess its all the rage these days. On this DB-9 fitting, most devices use pins 2, 3, and 5. Some devices require a null modem connection where they swap pins 2 and 3. (a reference to the days when people actually used modems, and if you connected two locally, had to swap the pinout for the devices, both masters, to communicate with each other). Those devices that use hardware flow control also may use ping 7 and 8. Then there are some more esoteric hardware level logic lines that you probably will not run into on typical gear these days. Anyways, its not so important to know for software types because it is a STANDARD, has been around for a long time, and everyone knows how to deal with it.

The second component of serial communications is the command language. This has absolutely no standard, other than it is well defined and predictable. Back when the only people who used RS-### coms were actualy engineers and programmers, there was little difficulty in adhering to this requirement. Now that the protocol is being used for more advanced (or at least for applications that depart from the traditional computer and its subsystems' realm) uses, and in some cases is being used by non-technical people, and in some even more pathetic instances where it is being designed by non-technical people, we see a trend towards the degeneration of RS-### coms into unclear and unpredictable dialogue. So, the quality of the coms varies from piece to piece.

Techically, when one asks for the RS-232 protocol, they are really only asking for the connection type and method, not anything at all to do with the actual language.

(long winded again)... So, RS-232 is really a few pages of technical background, that you should know, not because your really interested in it, but just so that you know the right language in case you ever have to talk to an engineer or developer about a problem (they like to be talked to in a certain way and get pissy if you don't follow the rules). I've never used RTI stuff, but it sounds like they make it pretty easy. 99% of us never really do anything THAT challenging, cause hey, were all solutions type of people and don't have the time to spend on joining the engineers in their little game of problem solving. I like to think that I'm smart, but to be honest, I can't really remember the last time that I was REALLY challenged by an RS-232 problem (and not because I was so smart that it didn't challenge me). Need something that is beyond the scope of what I've done in the past?, well look in the manual or command language document, read how your supposed to do it, implement it... it's that easy. If it's not that easy, well then the manufacturer is F'd up for writing such a piece of crap and they will not be using another one of their products in an installation that I have any say in specifying in the future... period.

I can't believe that Alan has the time. Some of us are busy. You can tell when I get busy, because I actually start posting here rather than working, a form of procrastination.