Phone cable or CAT 5

[PaulXmas]

Sounds like most use CAT 5 for their network.
Does anyone use phone cable?
I think phone cable would be cheaper and easier to use.
I use CAT 5 because I have more than a few laying around.
Pros and cons of each?

[Tim Fischer]

I'm using 100% phone cable this year. Cheap, and I like it because I can use the heat-sinks as sort of a strain relief-- I run the flat cable through a couple blades of the heat sink (I don't have my loads anywhere near where that would cause problems) and that keeps it from hurting the jacks if the wires get pulled. With Cat5 you have to do it some other way...

Cons, in theory, are lower signal reliability, but I haven't had issues with 17 controllers and close to 750' of wire total...

[Frank A.]

Good morning

I utilize cat 5 completely

even on the dmx equipment there is cat 5 used

just a choice

I have wired my house permanetly with the cat 5

and dmx cable

just have outlet boxes with the correct hardware for cat5 or dmx

mounted on the external/internal locations for controllers/fixtures

Frank A.

[Max-Paul]

Tim hit on one of the reasons for Cat5. Cat5 is twisted pairs. I am not sure if all phone cable uses twisted pairs or not. I am fairly sure that flat cable is not. With twisted pairs you have a small amount of noise or interference redustion. See the more twist the more capassative the wires become. This capassitance will aid in shorting out the interfence. Also Cat5 has those two spare pairs that one can use for several things. One is that you can run a passive alarm system. Not only can you use it to make sure no one disconnects your controller and tries to run off with it. You can extend those two leads to make a wire loop through some of your display elements. Or go to the contacts of a motion detector that is powered off of the AC line feeding your controller. Maybe contacts on a trip wire switch. Anything that would open the circuit.
I have heard that someone uses a pair to bring the audio out to a controller and then into a whole house transmitter. Another sent the auto to a small amplifier and then to some small outdoor speakers.

the above is not something you can do with telephone cable (referencing standard 2 pair cable). and the telephone cable not using a twist can not help block out interference and your communication may become compromised and your lights will flash when their are not suppose to. And dont flash when they are suppose to.

Yes, at this time Tim is lucky. Then one day he will add something and it might happen that his display is going to go crazy. Then too, he might just be blessed and never have it happen to him.
As for me and they way my luck runs. I will stay with the Cat5 and keep my fingers crossed that something weird does not happen.

[PaulXmas]

OK thanks for the information!
I ran on patch cable from my PC to the basement out to the controllers and another outside for testing.
I thought phone cable would be easier to use (smaller holes) and wire since you don't need any special tools, but I think I will stick with CAT 5 and hope it doesn't fail in -40C

: )

[Tim Fischer]

Yes, at this time Tim is lucky. Then one day he will add something and it might happen that his display is going to go crazy. Then too, he might just be blessed and never have it happen to him.
As for me and they way my luck runs. I will stay with the Cat5 and keep my fingers crossed that something weird does not happen.

I guess I've been lucky for 7 display seasons now then

Note that phone wire exceeds the spec for RS-485 communication, and Cat-5 far exceeds it...

[Denny]

Have used phone wire for four seasons without problem (other than two being chewed in half by rabbits). Used to run 14 controllers, iDMX1000, and firefly. Much cheaper to replace phone line than cat5e when the rabbits snack on it.

[Max-Paul]

Tim,

What spec. are you speaking of?? I truely would like to learn.

Denny,

Throw out some carrots, and bribe them to not chew on your phone wire..

[doug petschke]

You asked a serious question there

Simply put, he says that he can use phone cable and get the communication data information protocol (RS485) through the wires to the controllers and this informaton will reach the maximum length RS485 can travel with out a large error rate due to crosstalk, which critically slows communication if it is 2 way or the information is not decipherable on the recieving end by the reciever. in this case the controller.

Cat 5 is better suited for the RS 485 because the twist ratio is much better at preventing crosstalk and information can travel farther with less error rate because of the prevention of crosstalk. Don't forget that the chemical makeup of the conductor between the 2 are different as well. Some cases the size of the copper conductor.

Crosstalk by the way is interference created within the cable itself due to the vast amount of information being sent at high speed back and forth through the cable.

Standard telephone lines are analog and have a low bandwidth. They can only transmit data at a maximum speed equivalent to about 14,400 bps. Where as some cat 5 versions can carry data speeds of 100 mbps

Cat 5e can carry 1000 mbps

A lot of research has been put into this technology therefore every cable made has [glow=red]spec's[/glow] spec's as to it's own performance capabilities

Telephone will get the job done in most cases

Cat 5 will work better

WHEW

I sure that there are a bunch of electrical engineers that are on this site and will probably correct something I wrote but this gives you a general idea.

[George Simmons]

I use both to connect a total of 20 controllers and have had no issues whatever.

Paul - I doubt -40 will affect the cat5 unless you try to work with it. I imagine it gets pretty crispy in that kind of cold but if left alone should be fine.

[Tim Fischer]

Max-Paul wrote:

Tim,

What spec. are you speaking of?? I truely would like to learn.

The spec for RS485 communications. Sorry, don't have a link for it, but since it predates Cat-5, that implies Cat-5 isn't a requirement

[Max-Paul]

Look, to save everyone from wasting time and energy that one uses up in a fight. I am going to state this very simple rule that I live by as a troubel shooter and a systems intergrator.
Rule 1
Always use the best available. And for me that is not a ribbon cable with straight leads. Yes RS-485 was speced out to use twisted wire at 120 zohm wire. I dont have the spec in front of me and its been about 5yrs ago that I read the spec over and over, so it might be 100 zohms. And as some have found out that a terminator resistor at the end of the daisy chain sometimes helps to kill reflected waves that screw with some modules being able to see a clean signal.

Rule 2 is to do the right things from the begining so that you do not have to scratch your head later wondering why it did not work. If I do the right thing from the get go, then it is less likely I will have to scratch my head later.

Hence the reason Tim I said that your telephone cables are working now. But one day you might find your system acting strange and you will wonder what went wrong. And I am SUGGESTING that your phone cords might be giving you a false sense of security. But suggestions or advice is free and cheap, please do not make my suggestion become a command from apon high. That is not my intention. But if it helps you one day, then I get a warm fuzzy thinking that I was able to help someone out.
enough from me on this. All who read this know that I believe in maybe over engineering. Mind you I am German and we used to be know to build rock solid items. I dont like to build things and then have to fix them. I rather move on and spend the money once and not twice....

[Max-Paul]

Sorry if this is long, but I think it will help clear up any confusion. And I stand to be corrected. The Z of the cable and termination resistor is 100 ohms.

RS422/485 Application Note
Chapter 3: Selecting RS-422 and RS-485 Cabling Cable selection for RS-422 and RS-485 systems is often neglected. Attention to a few details in the selection process can prevent the costly prospect of re-pulling thousands of feet of cable.
Number of Conductors
The signal ground conductor is often overlooked when ordering cable. An extra twisted pair must be specified to have enough conductors to run a signal ground. A two-wire system then requires two twisted pair, and a four-wire system requires three twisted pair.
Shielding
It is often hard to quantify if shielded cable is required in an application or not. Since the added cost of shielded cable is usually minimal it is worth installing the first time.
Cable Characteristics
When choosing a transmission line for RS-422 or RS-485, it is necessary to examine the required distance of the cable and the data rate of the system. The Appendix to EIA RS-422-A Standard presents an empirical curve that relates Cable Length to Data Rate for 24 AWG twisted-pair telephone cable that has a shunt capacitance of 16 pF/ft. and is terminated in 100 ohms (see Figure 3.1). This curve is based on signal quality requirements of:
a. Signal rise and fall time equal to, or less than, one-half unit interval at the applicable modulation rate.
b. The maximum voltage loss between driver and load of 6 dB.
[align=center]
Figure 3.1 - Data Signaling Rate Versus Cable Length for Balanced Interface Using 24 AWG Twisted Pair Cable[/align] Losses in a transmission line are a combination of AC losses (skin effect), DC conductor loss, leakage, and AC losses in the dielectric. In high quality cable, the conductor losses and the dielectric losses are on the same order of magnitude. Figure 3.2 is included in this application note to point out the significant difference in performance of different cables. This chart shows Attenuation versus Frequency for three different Belden cables. Note that the polyethylene cables offer much lower attenuation than PVC cables.
[align=center]
Note 1: Above attenuation data is supplied courtesy Belden Wire and Cable Company
Note 2: Datalene is a registered trademark of Belden Wire and Cable Company. Datalene is a type of foamed cellular polyethylene insulation.
Figure 3.2 - Attenuation Versus Frequency for Several Data Cables[/align] Another approach to choosing transmission line is the "E-GRADE Program," which has been established by Anixter Bros. Inc. Anixter is a worldwide distributor of wiring system products. Under this program, Anixter divides data interface cables into four categories as follows:
E-GRADE 1 LIMITED DISTANCE
E-GRADE 2 STANDARD DISTANCE
E-GRADE 3 EXTENDED DISTANCE
E-GRADE 4 MAXIMUM DISTANCE
Simple charts are used to help the user select the proper cable without any technical understanding of the cable parameters. This program divides the usage categories into EIA-232-D, EIA-422-A, and EIA-423-A. When using this literature, use the EIA-422-A charts for choosing RS-485 cable.


THE RS-485 APPLICATION "CHEAT SHEET" by B&B ELECTRONICS
Use It Anywhere
The EIA/TIA RS-485 communications standard, an upgrade of RS-422, supports 32 devices (driver/receiver pairs) in a party line or multi-drop mode, on a cable of up to 4,000 feet for balanced differential signal transmissions at a common-mode voltage (Vcm) of -7 to +12 V.
You can internally or externally configure RS-485 devices. Four-wire connections, which require an additional ground, require a 'master' node (e.g., a PC) that communicates to all others, called 'slaves,' which in turn can only communicate with the master.
To Terminate, or Not to Terminate?
The RS-485 spec says to use termination. For high baud rates and long cable runs, this is true. In most equipment though, with max speeds of 115kbit, it is unnecessary. Adding termination dramatically increases power consumption and requires that the network be re-biased, which is rarely done. Termination complicates system design and rarely solves problems when used in the kilobit data range.
Extend the Network Easily
By adding repeaters, you get longer distances- each 'refreshed' signal can drive another 4,000 feet of cable- and 31 more RS-485 loads (driver/receiver pairs) per repeater. Long networks are especially vulnerable to grounding and surge problems. This is easily addressed by isolating the nodes. Use optically isolated repeaters and isolated converters to attach the nodes of your network and you'll have reliable long-distance applications.
Tips for Best Performance
Check the converter data sheet to see how the receiver's 'enable' function is connected. Test the interval after the last bit is transmitted to ensure complete transmission. A too-short interval causes missed parts of each character being sent. A too-long interval may cause the system to switch the data line from transmit to receive. Select appropriate isolation or shunting for protection against surges. When in doubt- isolate! Add a fuse-type device to shunting-type suppression to protect against short circuits to power conductors.
Use appropriate signal grounds- a must-have- and shielded cable- desirable- for safety.
Check signal types and related issues before writing or purchasing software protocols.
Device communication characteristics must be checked before completing system design.
Get a schematic of each serial port to assist in troubleshooting and repairs.


Well some of this last paragraph does not really pertain to us LOR users.
Max

[taybrynn]

Using CAT6 from newegg and monoprice ... been 100% reliable.

[-klb-]

Do note that the spec as quoted above calls for twisted pair phone cable. Typical "silver satin" is not twisted pair cable. But silver satin should still work fine in a low electrical noise environment. And, with single pair RS-485 like LOR, cross talk can't be an issue, as you only have one source talking at a time. Unless your cables loop back past themselves, in which case, you might induce an echo back into the line as crosstalk from a different loop.. But reduced susceptibility that twisted pair cable has to the electrical noise that phase angle dimming creates could be of significant value in some displays.

[Tim Fischer]

Max, I'm sorry if you thought I was "starting a fight". I was simply answering the original question:

Sounds like most use CAT 5 for their network.
Does anyone use phone cable?
I think phone cable would be cheaper and easier to use.
I use CAT 5 because I have more than a few laying around.
Pros and cons of each?

Others stated that phone cable is error-prone and causes nothing but problems. I simply stated that I've been using it since 2003 and now running 17 controllers with it and have had no issues of the type people are describing.

If you want to use Cat-5 by all means do so, but the original poster seemed to be asking about experiences with phone cable, and I seem to be one of the few people here actually using it so I chimed in.

Done with this thread now-- let the phone-cable bashing resume

[Max-Paul]

Tim my friend if I may call you this. I was not saying that there was a fight. I was saying I believe in my post to prevent a fight.

klb, there is a small chance of crosstalk, if someone uses one of the spare pairs to run audio out to a controller site and have their 1) amplifier for their speakers. 2) their FM transmitter at the controller site.

But that is just a small chance. Otherwise if only a pair is being used for the RS-485 signal. Then I am 100% in agreement, no crosstalk possible.

[terrypowerz]

I use 14/3 w/ground romex...

It is a bear getting the connectors on, but it is durable.

Talk about a warm and fuzzy feeling... knowing you can pull 15 amps on your com line.

[Max-Paul]

Hey Terry,

Bet you have no line loss out to 4000'.

Well I do know that in the USAF we did run the keying voltage on the same pair that the audio was on from the remove OPs center to our Transmitting site. And recently saw data comm on the 480 lines from the PLC to a moving piece of machinery.

Cross talk is any case were intelligents from one pair interfere with intelligents on another pair. Be it audio or data, or for that matter video, analog / digital.