CM11a cable

[Brandt]

ugh...i've gone through almost 2 packages of 4p4c plugs. I'd probably have to return to Fry's for another one...maybe the Shack carries them?

Even if a shorter run worked, and the 25' run did not...Then it still wouldn't do me any good :-/


I really want my CM11a plugged into the XTB-IIR!

Maybe if I used Cat5 instead of Cat3?

Maybe if I used a really long straight through 15?-pin serial cable (expensive)?

[Brian H]

I can think of a few things.

The CM11A uses the RI {Ring Indicate} signal. The USB to Serial Converter may not support the RI input from the CM11A?
Though your automation program may not use it if it is not Active Home.

The CM11A does not have a negative power supply voltage for its RS232 output signals and steals it from the computers RS232 Transmit Data Output signal into the CM11A. Maybe it is too low by the time it gets back to the converter. As it is routed through a few components like diodes and resistors.

You are using CAT3 wire and not phone style wire? I would think CAT3 vs CAT5 at the data rate and distance the wire length is. Would not make too much difference.

Have you used the CM11A with the USB converter and just the CM11 cable? That would give some clues as to where to check next.

[Brandt]

Heyu does use the RI signal.

CM11a works perfect with the usb converter and the stock cable.

I thought telephone line was cat3. my mistake.

I am possibly thinking about using an old cat 5 cable I have with the rj45 to db9 adapters on both ends and connect the stock cm11a cable directly to the cm11a.

[pconroy]

Maybe it just doesn't have enough power to get the signal down the lines...?

Just a point that may or may not be relevant.

When I made my CM11A extension cable - it was long, like 50' or so.
But, yes, it was hooked up to a real DB9 serial port on the PC.

This was 6 or 8 years ago, tho'...

[Brandt]

Here is the adapter I'm using:

http://www.parallax.com/Store/Microcontrollers/BASICStampModules/tabid/134/txtSearch/28030/List/1/ProductID/378/Default.aspx?SortField=ProductName%2CProductName

Since it says RS232, I am assuming RS232 levels and not TTL levels.

[Brian H]

The DB9 adapter to CAT5 network cable may work fine.

I did a test with my CM11A; spare IBM laptop and a breakout box for RS232. I am not sure when AH uses the RI but disconnected it didn't seem to care.

[Brandt]

Well I don't have rj-45 to DB9 adapters at the moment, so I thought I would try it with serial cables...not one, but two. Here is what I got working!

[Sheevaplug] -> [USB A/mini cable] -> [USB Hub] -> [USB Cable] -> [Parallax USB-RS232] -> [Serial Cable] -> [Serial Cable] -> [CM11a Cable] -> [CM11a] -> [XTB-IIR]


but the other more preferred method didn't work:

[Sheevaplug] -> [USB A/mini cable] -> [USB Hub] -> [USB Cable] -> [Parallax USB-RS232] -> [CM11a Cable] -> [Coupler] -> [25' telephone cable] -> [CM11a] -> [XTB-IIR]


The serial cables are definitely more robust than the telephone cable.. I wonder if that has anything to do with it...


The whole point of doing this was so that I could plug the CM11a into the XTB-IIR to try an improve the dimming with a palm pad. Using a TM751 with palmpad dimming is quick, smooth, flawless. but with the w800usb and cm11a dimming takes forever...approx. 3 seconds in between each dim step.