SBL2e-200 RS485 reference design and/or what do half- and full-duplex settings do?

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amarburg
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SBL2e-200 RS485 reference design and/or what do half- and full-duplex settings do?

Post by amarburg » Wed Oct 21, 2020 11:20 pm

Hi all,

I'm interested in using an SBL2e-200 out-of-the-box as a simple ethernet-to-half-duplex RS485 gateway. I will be assembling a basic baseboard with the necessary transceivers, power conditioning, etc.

I'm trying to figure out what the "RS-485 full" and "RS-485 half duplex" software settings mean from a hardware point of view .. if anything. Given the RS485 is (apparently) only available on port 0, I'm guessing the firmware could be using the RTS to drive enable lines on the transceiver (?). Or maybe not.

Alternatively, is there a reference SBL2e - to - RS485 transceiver design available -- maybe from the eval board?

Thanks!

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TomNB
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Re: SBL2e-200 RS485 reference design and/or what do half- and full-duplex settings do?

Post by TomNB » Thu Oct 22, 2020 7:19 am

Hello Amarburg,

The difference between the full and half is the way the RS-485 transceiver is configured and controlled. If you take a look at a traneiver data sheet, you can see the enable pins are set differently for half or full duplex. You are correct in that the RTS signal is used to control the 485 transmit enable.

I would recommend getting our EVAL-SBL2E-KIT. It has the SBL2e-200IR module, a dev board, and everything you need to see how the different modes work. You can also use the dev board as the reference design for your RS-485 circuit. That would be much less risk than coming up with one from scratch. Here is a link to the eval board: https://www.netburner.com/products/seri ... ation-kit/.

You do not need it for the project you describe since you are using the factory serial to Ethernet application, but just as a side note, the NNDK-SBL2e-KIT is a software development kit for the platform. It includes the same SBL2e-200IR module and development board, but also the development tools and software to create any type of application you wish.

Please let me know if you have any additional questions.

amarburg
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Joined: Wed Oct 21, 2020 11:12 pm

Re: SBL2e-200 RS485 reference design and/or what do half- and full-duplex settings do?

Post by amarburg » Thu Oct 22, 2020 7:37 am

That sounds good. I do have a dev kit on order ... are the schematics for the dev kit available (do they come with the kit?)

Thanks!

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TomNB
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Re: SBL2e-200 RS485 reference design and/or what do half- and full-duplex settings do?

Post by TomNB » Thu Oct 22, 2020 9:01 am

Yes, they come with the development kit. You also get a support account for engineering resources with the dev kit, so if you need any assistance we are happy to help.

amarburg
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Joined: Wed Oct 21, 2020 11:12 pm

Re: SBL2e-200 RS485 reference design and/or what do half- and full-duplex settings do?

Post by amarburg » Sun Nov 08, 2020 6:05 pm

Hi Tom,

I have my dev kit in hand. Maybe I'm just dense, are the schematics for the dev kit in the support materials? I'd like to ensure I get my RS485 transceiver connected to the SBL2e correctly.

Thank you,

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TomNB
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Re: SBL2e-200 RS485 reference design and/or what do half- and full-duplex settings do?

Post by TomNB » Mon Nov 09, 2020 1:31 pm

Not at all :) Great idea to look at the reference schematic. For a dev kit, C:\nburn\docs\Platform\Schematics. If you don't have a dev kit, please send an email to sales and we will send you any schematic you need.

amarburg
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Joined: Wed Oct 21, 2020 11:12 pm

Re: SBL2e-200 RS485 reference design and/or what do half- and full-duplex settings do?

Post by amarburg » Wed Nov 11, 2020 9:49 am

Hi Tom,

Thanks. I only got an eval kit, not a dev kit -- I shouldn't need custom firmware. I'll send that email.

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