485 Grounding In Harness With Power and Ground Question
485 Grounding In Harness With Power and Ground Question
(OP)
I am working on developing a system including a RS485 network. All microcontroller-based devices will be powered by a 24VDC lead acid battery system. Each system will contain a RS485 driver powered by an a 5V DC-DC buck converter. The device in question will be added to the end of a network, so the termination resistor will be built in.
I would like to power(battery supply and ground) and communicate(RS485 A and B) using the same harness and connector(4 conductor).
My question are:
1) Is a two-pair RS-485 cable harness sufficient for this application? Two conductors would be 485 twisted pair and the other two would be supply and ground. The conductors would be 22AWG. Max current would be 1.5A. Nominal current is about 50 mA.
2) Would the RS-485 twisted pair have to be separately shielded from the conductors supplying the power?
Thank you all for taking the time to read this post.
I would like to power(battery supply and ground) and communicate(RS485 A and B) using the same harness and connector(4 conductor).
My question are:
1) Is a two-pair RS-485 cable harness sufficient for this application? Two conductors would be 485 twisted pair and the other two would be supply and ground. The conductors would be 22AWG. Max current would be 1.5A. Nominal current is about 50 mA.
2) Would the RS-485 twisted pair have to be separately shielded from the conductors supplying the power?
Thank you all for taking the time to read this post.





RE: 485 Grounding In Harness With Power and Ground Question
1.5A on 22AWG over an extended distance could certainly be a problem.
In principal what you want to do will work.
What are your data rates and how far are you trying to go?
Keith Cress
kcress - http://www.flaminsystems.com
RE: 485 Grounding In Harness With Power and Ground Question
Dan - Owner

http://www.Hi-TecDesigns.com
RE: 485 Grounding In Harness With Power and Ground Question
Data rates will be 115kbps or lower, half-duplex.
Why can't the power and ground cables be twisted?
RE: 485 Grounding In Harness With Power and Ground Question
Dan - Owner

http://www.Hi-TecDesigns.com
RE: 485 Grounding In Harness With Power and Ground Question
RE: 485 Grounding In Harness With Power and Ground Question
Keith Cress
kcress - http://www.flaminsystems.com