question

darrencham avatar image
darrencham asked

ET112 to Cerbo 50 rs485

Hi. Is it possible to connect ET112 to Cerbo with 50 metre rs485 to usb cable

cerbo gxEnergy Meterrs485
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5 Answers
wkirby avatar image
wkirby answered ·

That should be fine assuming there is not too much noise along the way and the bus is using a proper twisted pair. One pair in a CAT5e network cable will be fine.
You will definately need to employ terminators at each end of the cable.

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darrencham avatar image
darrencham answered ·

120 ohm at each end ?

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wkirby avatar image wkirby ♦♦ commented ·

Yes, 120Ω on each end of the cable.

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Matthew Walsh avatar image
Matthew Walsh answered ·

@Darrencham did this work?

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darrencham avatar image
darrencham answered ·

Hi. I connected a usb to rs485 cable to cat5e over 50m then connected it to the et112. No resistors. It works perfectly. That is used for a grid meter. I also have the same connection but over 2m to connect a pv inverter also works perfectly.

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sanchuka avatar image sanchuka commented ·

@Darrencham hi, may you help me with some pictures of the cable connection please? I'm planning to install an ESS system using ET112 as a grid meter (Zero Feed In Electrical Company Regulation). In ET112 manual read some code color table on 3 pairs (Orange Data+, Yellow Data- and Black GND), did you connect cat5e to each color twisting cables for extension (50 meters)? or use some special tools/connectors? Thank you for your feedback, regards!


system-ess-to-be-installed.png

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darrencham avatar image
darrencham answered ·


  1. BF87640A-9622-468D-AE42-0E82F73B1FE3.jpegd6a87912-9446-468c-884c-c08262fae773.jpegImage Caption

     

    hi. My connection is for ess grid meter et112 to rs485 to usb on a cerbo gx the cat 5e cable goes directly into the Et112 and a small cat 5e in-line Coupler links the wires to the rs485 to usb connection only 3 wires are connected ignoring twisted pairs as long as the colours used are the same in the et112 as connected to the rs485 cable it does not matter which colours are used. Hope this helps. Good luck




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  • 6b63d3ed-555c-4839-ac57-a76d56f3c21b.jpeg

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Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

sanchuka avatar image sanchuka commented ·
@Darrencham Wow! Thank you very much! I really appreciate your time for take those photos. Will try on my installation more confident now. Thanks, Regards!
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