Author Topic: Nano 10 RS-485 terminating resistors  (Read 10998 times)

cch1955

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Nano 10 RS-485 terminating resistors
« on: June 29, 2010, 11:36:33 AM »
I am setting up Nano 10 for programming via RS 485 to U485 USB converter.

Instructions show 120 ohm terminating resistor across RS 485+ and RS485- lines. Is this needed when U485 converter and Nano 10 are only devices on RS-485 lines?

In addition RS-485+ is pulled up to +5VDC by 1k resistor and RS-485- is pulled down to ground by 1k resistor  are these both needed for only U485 and Nano 10 on RS-485 lines?

Also is there a Ladder+Basic programmer?s reference for the Nano 10 ?

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Re:Nano 10 RS-485 terminating resistors
« Reply #1 on: July 01, 2010, 12:30:26 AM »
Usually if the distance between the PLCs and the PC is short there is no need for biasing resistors. It should work well just by connecting two wires.

You can download the same i-TRiLOGI software manual for M-series, F-series or Nano-10. They are the same software:

http://www.tri-plc.com/documentlist.htm
Email: support@triplc.com
Tel: 1-877-TRI-PLCS

cch1955

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Re:Nano 10 RS-485 terminating resistors
« Reply #2 on: July 01, 2010, 08:49:16 AM »
I just used the 120 ohm resistor across the 485 +/- lines and it worked fine. The CD that comes with the U485 adapter has a document that confuses the issue. I think shipping a TRI doument on the CD that outlines 485 connections and termanation issues would make the product even better.

Nano 10 is a great product ! I have used ADC inputs, PWM outputs to direct drive 2 DC motors in seperate PID loops, the devlopment was quick and the results excellent.

Also for applications that require absolute rotary feedback with long life this sensor is helpful. It interfaces directly with TRI ADC inputs and supply voltages. http://sensing.honeywell.com/index.cfm/ci_id/140301/la_id/1/pr_id/128790.htm