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VCTF cable for Compobus/S and CompoNet

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Hi guru and peers, In Compobus/S and CompoNet documentation, VCTF cable is specified for use as fieldbus cable. So, what the heck is VCTF cable? I searched Internet but couldn’t find a definition and explanation of this cable type. If I'd use a normal electrical cable, does it affect communications at all and in what way? If anybody has a practical experience using this cable for Compobus/S, pls give me some advice. Many thanks.

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I never figured out quite what VCTF stands for. However in a recent project we used the recommened Belden cable 9409 for our Compobus network with no problems. http://www.belden.com/pdfs/Cable101/PLC-DC...eX-RefGuide.pdf https://edeskv2.belden.com/Products/#s=9409&r=0

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You ain't gonna believe it, but... VCTF is the Japanese attempt to translate Vinyl Rubber into English. It stands for Vinyl Cab Tire. Get it? Cab Tire = Rubber. Go figure.
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Got the VCT part. Not sure I completely believe you, UNLESS you can tell us the Japanese translation for F !!! Vinyl Cab Tire F.......

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the F is obvious Flat. VCT is indeed the correct explanation which you see popping up al over omron related to cables. regards, MPM

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Questions: - What is the structure of VCTF cable ? - In a nutshell, what is the difference btw VCTF cable and normal electrical cable ? As I see that most comm. or fieldbus cable uses one or both of techniques to guard against noise: shielding and twisting pair. If I'm not wrong, VCTF doesnt use any of those techniques Side note: If F stands for Flat, then Omron wouldnt differentiate VCTF and Flat cable at all.

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Hi. it stands for " special flat cable " http://www.ia.omron.com/product/82.html

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This sure doesn't look FLAT to me. http://us.100y.com.tw/PNoInfo/26740.htm

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Flexible?

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Anyone has practical experience about this type of cable? Compobus/S has been around for long time, and there should be many experiences around to share.

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For CompoNet and formerly for CompoBus S (do not use it anymore), I just use 7/0.20 twisted pair screened or 2 pair screened if I need to power the comms module from the PLC rather than at the other end. Usually have to drop the speed right down over any distance of course but have not had any problems to date. The main issue is to make sure the DC supply is within the required range.

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I have successfully used 0.75 sqmm, shielded, twisted pair communication cable from local cable manufacturer for distance up to 300 m. One system is running for last 7 years without any problem. The units were set for 'Long Distance Mode'. VCTF : Vinyl Cab Tyre Fiber (As per Omron manual W120-E1-08 page 65) SVN

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Yes this is correct, it has to be 0.75 sqmm. It can be also normal electrical or audio cable. It has to be below 25 Ohm per km. No Impedance specified, so all possible. I made some tests, cable with 0.75 sqmm works better than thin communication cable!

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I'm still curious, Is there any reason that it has to be 0.75 sqmm? Because in communications, impedance, capacitance and noise shielding are key points. Anyway, practical experience and test makes more sense

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I've used a lot of different cables for Compobus/S and never had any problem. The longest distance is around 150 meters in high-speed mode with a 2x0,5 unshielded round PVC-cable. But I've also used 3x0,5 shielded cable on the same type of machine without any problems. Besides the too long distance (Omron states max. 100 meters in high-speed mode) the Compobus-cable is also tied to a 3x400Volts 50Hz-powercable over al least 100 meters.... Never had a single glitch in communications.....

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CompoNet runs actually on anything that holds copper and is 0.75 sqmm. Shielded or un-shielded. As Harald says it should be below 25 ohms per km. VCTF is in Japan also known as general appliance wire. Like the cable that is connected to your toaster. I've seen CompoNet run over normal what we in the Netherlands call VMVK-cable. This is used to put up your lighting.
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