more help for size of optical cable

[sugandh]

One more question ,is there how can i decide for my fibre cable type, how can i check the bandwith . normally how can i know the sensors (proximity,capacitive,etc.) bitspersecond of sensors and limit switches,so that it will fit the desired optical cable bandwith.
i am in a confusion whther 28-30 input sensors and limit switches will require how many plastic claded silica fibre or POF.
and 2nd can analog signal be feed into plc input after converting it to digital.(eg.potentiometer signal)

 

[davenn]

I would have thought that the bandwidth is more limited by the equipment you are using to do the multiplexing of the channels, and the style of multiplexing ....
time division mult. TDM, freq division mult, FDM etc etc. you want 20 - 30 channels ?
a fibre of hair thickness can easily support ~ 2000 channels.

fibre size isnt the issue for you .... the technology hanging off the end of it is what counts

Dave N

 

[sugandh]

ok thanks a lot
i got the idea but i will just want to clearify to u what i am thinking of,
i want to use optical fibre (plastic or plastic claded silica fibre cable) in my machines having 4 parts each parts consist of 20-30 input devices (sensors,LS,potentiometers)taking this to plc and then from plc to motors output.
there is lots of copper cable wiring ,including junction boxes,housings,cable ties,marktubes,time consuming termination and relays.distance of cables will be approx. 4m to max 20m .
i want to reduce time of working using optical fibre if all signals from input devices will be one signal, multiplexing it and transferring it to plc and again convering these to operate plc.so will it be feasible coz i have to also chk that the cost is reduced from old design and not a single penny is increased. i am afraid that the electronics required will be expensive like the connectors for conversion of signal.and the cost of cable i am not able to get anyehere.
machine is too expensive about 250,000 usd to 400,000 usd and manufacturing units are many in a year.
will it be feasible?can u suggest me site where i can get the cost of cable and its parts for this project?

 

[davenn]

The cost of optical fibre cable is relatively cheap
the cost of the multiplexing electronics is !!

you may find it cheaper just to run multi core copper wire cable between the 2 locations considering the short distance involved. i would only consider fibre if the cable was going into an extremely hi RF field area or a very hi voltage area
eg. an electrical power substation

cheers
Dave

 

[sugandh]

that i know the people are saying this but automobile companies like bmw and mercedees have used plastic cladded silica fibre cable in cars to reduce cost (MOST and BYTE flight cables they have invented) so if they can reduce cost in cars with short distances i think it could be done.

 

[davenn]

that i know the people are saying this but automobile companies like bmw and mercedees have used plastic cladded silica fibre cable in cars to reduce cost (MOST and BYTE flight cables they have invented) so if they can reduce cost in cars with short distances i think it could be done.

yes but they have 10's or 100's of 1000's of dollars to spend you dont and when they do it in mass production it makes it much cheaper over all rather than a one off system like yours

you would need to investigate what various companies have to offer for the interfacing electronics and then do your costing. I'm not into purchasing of that sort of equip. so I cant help you with company suggestions.
Google is your friend

Dave