RS-485 Network multiple connector

Tracteur · May 31, 2011

Hi guys, I've to connect some rs-485 component. My problem is that each device have a different connector type.
The breakers (Masterpact NT) (seven in fact) have screw connector, the second a Modicon 340 have a rj-45 connector and finally a Ge Versamax that get a db-9 connector.
I'm totaly lost. The master will be the GE.

Thks in advance.

danw · May 31, 2011

I'd suggest that you consider breaking the DB9 wiring out to screw terminals, so that you can wire without spurs or stubs.

RS-485 is intended to be daisy chained, with incoming line on the same terminals as the outgoing line.

The incoming/outgoing line is not supposed to go to a terminal strip from which a separate pair of wires spurs or stubs off to the device.

By breaking out to screw terminals, you have flexibility for wiring that is awkward with DB9 connectors.

http://www.google.com/products/cata...ei=sffkTflqh7-BB-Wn8KIG&sqi=2&ved=0CFAQ8wIwAw#

Tracteur · May 31, 2011

Yeah nice idea ! Did you think that http://www.bhphotovideo.com/c/product/539197-REG/NVT_NV_RJ45A_NV_RJ45A_RJ45_to_Screw.html could work for the rj-45 connector ?

Mickey · May 31, 2011

Now of-course you going to have to figure out the pin-out.

danw · May 31, 2011

I suspect the RJ-45 adapter with its transparent housing can be easily figured out because the wiring is in-line.

Which of the 9 pins in a DB9 are brought out to the 5 screw terminals is up for debate. Time for an ohmmeter . . . .

Hopefully it's the pins needed, because there is no standard or even convention for RS-485 in a DB9.

caddymac · May 31, 2011

Would something like this work for the DB9?

http://www.automationdirect.com/adc...Link_Specialty_Modules_-a-_Cables/ZL-RTB-DB09

danw · May 31, 2011

The cable that connects the DB9 on the device to the DB9 on the DIN rail adapter (above) is a stub or spur cabling. Stub/spur cabling creates reflections. That section of cabling/wiring needs to be minimized.

OkiePC · May 31, 2011

Dan those are awesome little golden nuggets of information that could apply to a wide variety of situations, thanks.

danw · May 31, 2011

You sir, are most welcome.

Steve Bailey · May 31, 2011

The DB9 on a VersaMax CPU is RS232 only. The DB15 is RS485.

danw · Jun 3, 2011

Just got another adapter in my email box this morning:

RS-485 Network multiple connector

Tracteur

Member

danw

Lifetime Supporting Member

Tracteur

Member

Mickey

Lifetime Supporting Member

danw

Lifetime Supporting Member

caddymac

Member

danw

Lifetime Supporting Member

OkiePC

Lifetime Supporting Member

danw

Lifetime Supporting Member

Steve Bailey

Lifetime Supporting Member + Moderator

danw

Lifetime Supporting Member

Similar Topics