Extending RS485 on Elk M1G with media converters
- Thread starter lfoley
- Start date
Once you introduce fiber converters into the mix you may have timing issues. I have had some experiance with other products that have had some quirks. For example, once you install one remote device on a data port you have to use drop and repeat fiber units for all devices on the data path. Spanky would be the best person to ask on this one.(As with all other Elk related issues)
Steve
Senior Member
You can just contact Spanky (David) via Elk Support. Brad or Amy can get him if needed. Or he will probably reply here when he sees this. I guess my 'curiosity' is why you need to do this in the first place? I thought the bus over standard copper was good for quite a distance (like 2000 feet or so iirc).
Remote building...Install another ELk M1G or EZ8. The cost of the fiber units would be very close to, if not more than the extra panel, IMHO.
Depending on how much fiber you have it would be a shame to waste 2 strands on such a low bandwidth.
Ahhh, I see. If you are willing to use fiber there are dry contact fiber converters out there or even IP based solutions. You may not have the supervision depending on the model but is an option.
Here is an example:
http://www.ifs.com/downloads/datasheets_en...ectdecr3000.pdf
I can transport and supervise Applied Digitals RS485 gear through the link as well. I also neglected to mention the need for a remote keypad on the same node.
I’m a big fan of Elk Products and was intrigued by the possibilities of this project and future projects that may fall into a similar realm.
I’m a big fan of Elk Products and was intrigued by the possibilities of this project and future projects that may fall into a similar realm.
Spanky
Senior Member
You have about 4 milliseconds from the end of a data packet until the acknowledged data starts flowing in the opposite direction on the RS-485 data bus. The turn around time of the repeaters normally kill the first byte or two of data that is being returned.
Due to the turn around time you can not put two M1DBHR active data bus hubs in series on the M1 bus. It takes too long for the combination of the two, to reverse the data direction without loosing characters.
Due to the turn around time you can not put two M1DBHR active data bus hubs in series on the M1 bus. It takes too long for the combination of the two, to reverse the data direction without loosing characters.
