Lantronix UDS1100 in multidrop RS485 application

Jan 02, 2007 4 Replies
C

Hi,



I've got an application that requires a number of environmental controllers be connected on an RS485 2 wire half duplex multidrop bus. I was looking at the Lantronix UDS1100 device servers (or even the older UDS100 / UDS10 ) to let me use the customers LAN so as to save wiring costs.



I know a couple of UDS1100's can be placed back to back and tunnelling used to create a transparent RS485/422/232 link between them but does anyone know if it's possible to arrange, say five, units to form part of a multidrop network for remote nodes on the network. I suspect that I'm only going to be able to arrange a point to point connection between two device servers at a time, but wondered if anyone has been able to broadcast data sent from one unit to a group of other units simultaneously?



thanks,



Colin


Vote
Twitter Facebook LinkedIn
C

... snip ...

Tunnelling?

Yes, but you have to control who is the master somehow. Time slots after an addressed 'permision to transmit' will do.

RS485 is a hardware scheme. The protocol is up to you.

Chuck F (cbfalconer at maineline dot net) Available for consulting/temporary embedded and systems.
Vote
Twitter Facebook LinkedIn
G

I don't know about he Lantronix units, but I do know that Comtrol's device servers can be configured that way: you can configure a DeviceMaster RTS unit to send data received on a port to a list of other ports/units. [Disclaimer: I work for Comtrol]

I presume you're using a single-master, multiple-slave protocol on the RS-485 portions of the network?

Grant Edwards grante Yow! Let's send the at Russians defective visi.com lifestyle accessories!
Vote
Twitter Facebook LinkedIn
G

Across the Ethernet connection between the device-server units.

Due to the nature of delays on the Ethernet TCP/IP or UDP link(s), the timeslots would probably have to be pretty course. I think that any Peer-to-peer protocol is going to be pretty tricky. A single-master command/resposne protocol should work easily enough.

Grant Edwards grante Yow! I represent a at sardine!! visi.com
Vote
Twitter Facebook LinkedIn
G

I forgot the link:

formatting link

If you want to do something particularly specialized, there's a software development kit that allows you to write a custom application to run on the device-server.

Grant Edwards grante Yow! HUMAN REPLICAS are at inserted into VATS of visi.com NUTRITIONAL YEAST...
Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required