Is there such a thing as an "SC Crossover" coupler or cable

A SC duplex cable (2 SC connectors on a "zip" pair of fiber) will probably have the two SC connectors placed side-by-side with a plastic housing that keeps them paired. Some housings simply have the SC snap into them, others have a plate that you have to slide out of the way to remove the connectors so you can swap them.

On the "zip" cable one of the fibers will have labling on it noting the fiber type and length markers. We will put a wire tie on (barely snug) that lead of a patch cable at both ends, it helps us identify a fiber of the pair. One end with a wire tie will go into the xmit of the fiber interface on device A, and the corresponding end goes to the rcv interface on devicd B.

JD

ohaya wrote:

JD,

I've seen some "SC-to-SC Patch" cables (vs. "SC-to-SC Duplex Patch" cables), and they look similar, except that the "Duplex" cables have a housing attaching the two SC connectors together.

But I noticed that some of the ones not labelled "Duplex" have black tips, instead of white tips. For example, here's a non-Duplex labelled cable:

and here's one labelled "Duplex":

Also, it might be just be me, but it looks like the black tips are LONGER than the white tips?

I'm thinking that if I got one of the former cable, since the connectors are not tied together, I could easily swap the ends to make my "crossover"?

Jim

JD wrote:

Hi,

Oh, I forgot one other question: If you look at the description on those links, it says "100 Mbps". I thought we should be able to run GigE over these fiber optics cables?

Jim

ohaya wrote:

Hi,

I went into the office this morning, and found that we had a bunch of plastic "SC couplers". These are small plastic things and have female receptacles on both ends. Their meant to allow you to extend the SC cable by plugging in SC patch cables.

But, I also looked at some SC cables we have, and they have those small, longer white tips. I would really like to try to do the crossover with one of the cables that I linked below, probably the non-duplex one (so I wouldn't have to split the connectors apart, with one of these SC couplers on each end.

Can anyone confirm that the black and the white tips won't make a difference, i.e., would work?

Thanks, Jim

ohaya wrote:

Hi,

I think I got things backwards, the connectors with the white tips are shorter, but I think that I've also figured out why, and it's pretty stupid :(.

I think that the image with the connectors with the black tips are actually the (black) protective covers (BIG sheepish gring)...

Jim

ohaya wrote:

Yes, in fact all standard duplex SC patch cables and couplers are crossover (A to B, B to A).

Hi All,

I was able to get an SC-SC patch cable working today, but I'm still curious about why the links that I pointed to indicate "100 Mbps"?

I am using this patch cable with GigE fiber interfaces, and it seems to be working.

Jim

True, but not all manufacturers follow the standard in this regard, The best way is to follow the cable markings: on a zip-type cordage the marks are normally printed only on one side, so you always know which fiber ends where at the opposite end. One other trick is: you only need the crossover cable on one end, and the straight-through on the other. So, if you are buying two cables with clipped SCs of the same kind, you are bound to have that problem! I prefer to buy the SC-SC duplex cords with connectors NOT clipped together. That gives you the flexibility to swap the ends when needed.

I am assuming you are using multimode fiber.

10/100 meg ethernet on multimode (62.5 micron) is good for 2 kilomter 1000 meg (gig) on 62.5 multimode is good for 220 meters. 1000 meg on 50 micron is good for 550 meters.

JD

ohaya wrote: