Caddx/Ademco Downloading

Edwards did it. The FireShield panels which I worked on with them work with standard modems. I forget what the maximum speed is but IMO that's not so important as modem compatibility. The entire EEPROM only holds a few K so any modern modem can DL the whole thing in a few seconds.

Well, IIRC, any modem that uses the hayes command set can be limited to a max connect speed.

In fact, I looked it up, and ATN0 will tell the modem to only handshake at the speed set in register 37, so in theory,

ATS37=1200 ATN0

Should set the max speed to 1200 Anyone have an external hayes-compatible and a alarm panel to play with?

Memory tells me the hayes 1200 / 2400 cost about $80 14 years ago. Certainly they should be worth no more than $10 now. After all, who buys them? Alarm installers?

If you really need one bad, I would suggest going to a local company, if you can find one that seldom throws stuff out, and ask. Governments (who have rules about tossing stuff) and charities might be good choices. I'll keep an eye on the goodwill stores around here.

I don't know if you figured it out yet but at least for the DL900 on the modems with the volume controls set the volume in the modem setup to NA because the command hadn't been invented yet so it gives an error.

whppas wrote:

I wonder if thats why I cant get mine to work?

In theory yes, in reality companies followed the Hayes command set about as well as RLB follows newsgroup rules. Just becausse a modem can get down to

100 baud does not mean it will talk to a specific panel

Telecom companies buy them in quantity for line testing, depending on the model you'll get the 1200 for between $40 and $70, depending on which 2400 it will be $25 to $40. you can verify this by bidding on a 1200 at Ebay

Correct, alarm panels communicate between 100 baud to 300 baud depending on the panel

That's not the problem. The problem is that so-called Hayes-compatible modems really aren't. They communicate okay at standard speeds like 300,

1200, and 2400, but the Bell 103 spec calls fror the modem to communicate at any desired speed between 0 and 300 baud. The clone modem manufacturers figured no one would want to run a modem at 75 baud, so they didn't implement that feature.

As to why panel manufacturers don't include modem chips, the reason is simple: cost. If you are selling panels for under $100, every part counts, and the fewer components you use, the more money you make. This was particularly true when remotely programmable panels were first introduced, and "high speed" modems would have been a massively expensive feature to include. So, the panel manufacturers used the panel's microprocessor to do direct serial I/O, which meant their only cost was firmware development: no additional components required. This unfortunately imposes speed limitations, but at the time these panels were first introduced, 1200 baud was considered fast.

Now, the manufacturers are faced with a backwards compatibility problem. If they built a panel that used a 56K modem to download, that modem would be incapable of slowing down enough to program older panels. Dealers would have to have two modems. They would bitch, and it would generate lots of calls to tech support. Plus, panels would cost a little more.

- badenov

the hayes commands also let you set the DTE (equipment) communication speed. Well, not set it, but let it auto discover what the rate is. I believe it's \\J or \\J0

I'm not trying to argue, by the way, just trying to save you all some money next time you need one.

To quote from

An issue which can be very confusing is the difference between the line speed (the data transfer speed on the telephone line) and the speed on the serial line between the DTE (computer) and the DCE (modem).

First, there is always some general confusion about the line speed, because some line speed is given with taking compression into account, while other data is given without taking compression into account. Also, there is a difference between bps and Baud due to the modulation schema used on the line. In addition, marketing blurbs obscure the picture. We will not make any attempt to clean up the long-standing Baud vs. bps confusion here (it is hopeless :-)). It is just recommended that whenever the modem returns information about line speed the above mentioned differences are taken into account to avoid any misinterpretation.

Second, the speed on the telephone line does not necessarily have to be the same as the speed on the serial line. In fact, it usually isn't on modern modems. It is recommended to set the DTE/DCE speed to a fixed speed instead of following the line speed. Logically, the fixed DTE/DCE speed should be large enough to cope with the highest expected line speed. V.90 modems should e.g. be accessed via 115200 bps or higher on the serial interface.

Setting the DTE/DCE speed on modern modems is quite simple. They all use autosensing on the serial interface. That is, they themselves detect the speed of data as received from the DTE and use the same speed to return data to the computer. They usually also autosense the parity, and 7 bit / 8 bit data length. Usually modems assume one stop bit when autosensing the serial interface.

When a modem sets up a connection with a remote party it can report the used speed. In fact, it can report the line speed or just the DTE speed (some modems can report both). The end user is most probably interested in the line speed, and not the DTE/DCE speed. So from this point of view, it is best to set the modem to report the line speed, and e.g. write the received information to a log file. However, some old communication software or modem drivers interpret the response from the modem as a request to change the DTE/DCE speed. In such cases the modem must be set to always return the DTE/DCE speed. Since this DTE/DCE speed will be the same as detected via autosensing there will be no speed change.

In the rare case that the DTE/DCE speed should indeed follow the line speed, the responses from the modem should of course be set to return the line speed. Then the DTE software has to evaluate the response, and change the DTE/DCE speed accordingly. This is really not recommended these days.

See the #W: Negotiation Progress Message Selection command for details on how to set which response to get.

Note: Some modem manufacturers call the DTE/DCE speed DTE speed, and the line speed DCE speed. Others distinguish between DTE speed (DTE/DCE speed on the serial interface), DCE speed (bps between the modems), and line speed (Baud rate between the modems).

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Understood however after sampling literally 50 different modems and altering just about all the available settings I've found one truth which is if the modem isn't listed by the panel manufacturer it won't work and cannot be made to work

manufacturers

And alarm manufacturers will not spend the money adding a true modem when less than 5% of their customers download panels

Where did that statistic come from? That seems way too low. Even if the panel was originally programmed by the installer on-site, everyone I know of has downloaders for doing diagnostics and minor changes like code additions and deletion.

And I'm sure he "sells hundreds" just like you.

I think that depends on the dealer and the panel brnd he uses most. The DSC factory guys tell me that 90% of their dealers don't download. Bosch is nearly 100% that do download and Napco and Honeywell are in the middle. I don't know if there are any formal surveys to back up that information or not.

The numbers are skewed somewhat as 10% of installers are probably doing 90% of the installations. Companies that do lots of installations are more likely to use downloaders.

How do they know? I mean, I've been a DSC dearer for several years, but no one from the factory has ever asked me if I download, and I'm a download-a-holic. js

I was told the 5% by Honeywell and DSC reps but something else to consider is...

Bosch you pretty much have to since the only other method is with an $800 programmer although the new panels are keypad programmable

Napco is so slow and time consuming it's almost mandatory

DSC can be keypad programmed quicker than I can connect with it via downloader

Honewyll isn't that far behind DSC

Our reps apparently have and I do as well, many people just don't like screwing with computers and learning software if they don't have to and it's easier for them to just roll a truck

I still don't buy that. I've worked for every alarm company in the world almost (according to everywhereman) and they all download the systems at one time or another. ESPECIALLY dealers that just screw with Ademco and DSC have the modems in place and USE them, as those two panels are the most widely used.

The figure the reps told you was probably based on some obscure survey that the rest of us never were invited to, or bothered responding to.

You are in a unique position to do your own survey.