CM11a cable

[Brandt]

Can you extend the length of a CM11a cable with a coupler and a standard 4 conductor telephone cord? If so, how long can it be?

[-Bill- (of wgjohns.com)]

Well, if the CM11A only has 4 wires, then probably.

I've never tried it with a CM11A, but it is a basic serial device and I have extended serial lines using CAT5 wiring probably 100 feet or so and run reliably at nearly 20,000 bits per second.  I'm pretty sure the CM11A doesn't talk that fast, even without looking up its specs.   

It will depend mostly on how much power the CM11A can put on its serial lines.

[dbemowsk]

I would say that you should be able to use any 4 conductor telephone extension with RJ11 jacks.  Make sure though that it is a 4 conductor cable and not a 2 conductor.  The RS232 standard states a maximum length of 50 feet, but if you are communicating at lower baud rates like 9600 you should be able to go longer with some degree of reliability.

[Brandt]

What baud rate does x10 use?

[JeffVolp]

What baud rate does x10 use?

From the X10 "Interface Communication Protocol" document:

The serial parameters for communications between the interface and PC are as follows:

   Baud Rate:   4,800bps
   Parity:      None
   Data Bits:   8
   Stop Bits:   1

(Google is your friend.)

Jeff

[Brandt]

Cool thanks, I'm going to plug my CM11a into the XTB-IIR, but it will require me to run some telephone cable...

[pconroy]

I had about 30' of cord in between mine at the PC a few years ago.  No problem.

[Brandt]

Wow so I bought an rj-11 telephone coupler and i pull the cable out of the bottom of the HD11a only to find out the jack size is different :-/

Any suggestions?

[Brian H]

The jack on the CM11A {probably the other variants of the CM11A also} is not an RJ11/12.
It is the smaller one used for connecting the handset to the phone base.

I will search around and see if I can find anything out.

[Brandt]

oh I see it is a 4P4C:

http://en.wikipedia.org/wiki/4P4C


so I guess I need a 4P4C couple and cable... 

[Brian H]

Yes if you can find them.
I believe it is also known as an RJ9.

[dbemowsk]

If I remember correctly, an RJ9 will fit into an RJ11 jack and still work.  Much like an RJ11 will fit into an RJ45 jack.

[pconroy]

Yes if you can find them.
I believe it is also known as an RJ9.

Wow - the only thing that pops into my head is RJ22.
But that's from a set of neurons not activated in 10 years!

[Brian H]

Yes the you can plug the 4P4C connectors into the 6P6C or 8P8C jacks. As the wiring works from the center out for the pairs of wires.
Well except for real networking cables where the pairs don't work out from the center.

I guess if you where careful.
You could get some 4P4C connectors and make a custom cable.

[dave w]

But that's from a set of neurons not activated in 10 years!

Exciting when that happens!