Industrial Fibre optic connectors for bad environment and vibration installations - Page 1
Forum section: electronics / projects

author: NW27
author_rank: Regular Contributor
timestamp: June 02, 2018, 09:25:37 pm
content: Hi allI'm designing a system that will have two enclosures with electronics mounted on a vehicle used in a rugged terrain area.I will have a micro at either end using a standard serial port comms running at least 115200 baud, maybe up to 2M.I'm looking for suggestions of actual fibre termination points/connectors that are mechanically robust and can handle vibration ideally with say an IP54 rating on the panel mount.I mention the micro interface because ideally a simple rx/tx connection between the micro and fibre would be good.Any ideas?Thanks Neil.

author: jbb
author_rank: Super Contributor
timestamp: June 03, 2018, 12:11:20 am
content: Others may have some suggestions, but I don't have a recommendation off the top of my head.I have had good results with industrial plastic fibre optics (e.g. AvagoAFBR1521 and AFBR2521) but neither the connectors nor the fibres are rugged. Kinking or crushing the fibres can break them.I have to ask; why fibre? An RS-422 link should be capable of these data rates and fairly robust against noise. If maximum noise resistance or electrical isolation is required, isolation can be added to one end of the scheme.

author: ajb
author_rank: Super Contributor
timestamp: June 03, 2018, 04:41:25 am
content: If you really do need fiber, Neutrik has a number of nice connector/cable options. I believe they're mostly IP65 when mated:http://www.neutrik.com/en/data/opticalcon/

author: NW27
author_rank: Regular Contributor
timestamp: June 03, 2018, 08:10:21 am
content: Thanks for the feedback and links.There are external certification factors that are driving the fibre connection.Sent from my SM-N920I using Tapatalk

author: max_torque
author_rank: Super Contributor
timestamp: June 03, 2018, 09:08:22 am
content: how 'disconnectable" do you need the fiber to be?two options seems possible:1) if the lid can some off the device, then route a fibre through a custom mechanical pass through (ie fibre bonded into a threaded and o ring sealed part etc)2) if the lid can't come off, use a suitable sealed / restrained connector (ie MIL spec) with the fibre transciever potted on a small pcb into that connector, that way the I/O through the box is electrical, and hence easier to source

author: Twoflower
author_rank: Frequent Contributor
timestamp: June 03, 2018, 09:47:44 am
content: Have you checked the MOST standard for automotive optical bus systems. They're using POF (plastic optical fibers). Because that system is designed for automotive means there are automotive compliant connectors available.But in general you should check other things fist. Maybe you did but just in case. Some things that comes in my mind: What type of fibers are required (POF, single- or multimode fibres). What type of optical cables will survive your environment (vibrations, strain, chemical, temperatures, ...). How much space is available (especially if you need strain relief). How much space is there for the connector to be fixed. Is there any electrical connection running along with the fiber (I've seen MOST connectors mixed optical/electrical)? Is mating/unmating in rough environment required (that will probably will be a huge problem, esp. if you use multi- or even single mode fibers)? Having a pigtail (short piece of fibers with a connector) coming out of your box an option?Maybe this alone will rule out some solutions are make the search for a solution easier/harder.

author: dmills
author_rank: Super Contributor
timestamp: June 03, 2018, 10:22:46 am
content: Expanded beam connectors of various sorts are popular with the broadcast crowd as they survive dirt and rough handling very much better then anything utilising a butt splice.Kind of expensive however, and at your very low data rate cheap 1mm plastic fibre might be a better option, but it depends on what level of robustness you need.Regards, Dan.