LPC MicrocontrollersのトピックRe: interfacing rs 845 bus

interfacing rs 845 bus

santoshganachar — Thu, 24 May 2018 10:24:40 GMT

hi how to interface lpc54114 to Rs 485 modbus device

Re: interfacing rs 845 bus

kerryzhou — Mon, 28 May 2018 07:42:12 GMT

Hi santosh Ganachari,

Actually, RS485 is just need to control the RTS in the UART module.

LPC54114 UART module already contains the LPC485 control function, you need to use the RTS connect the LPC485 send enable pin. Then the detail MODEBUS control, you just need to send the according UART data is OK.

About the according register, please check this chapter in the user manual carefully.

Wish it helps you!

Have a great day,
Kerry

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Re: interfacing rs 845 bus

george — Thu, 11 Oct 2018 08:59:20 GMT

Dear kerryzhou‌

Please let me do the question relevant to this post.

Is an RTS pin valid also in ISP mode?

Best Regards,

George

Re: interfacing rs 845 bus

kerryzhou — Thu, 11 Oct 2018 09:18:29 GMT

Hi George,

Unfortunately, in ISP mode, the UART just support UART_TX and UART_RX, no RTS is used, please check this information from the user mannual:

So, if you have the demand to use the RTS pin, maybe you need to create the secondary uart bootloader.

Wish it helps you!
Have a great day,
Kerry

Re: interfacing rs 845 bus

george — Fri, 12 Oct 2018 02:17:18 GMT

Dear Kerry,

Thank you for the kind explanation.

I see.

Thanks,

George

Re: interfacing rs 845 bus

kerryzhou — Fri, 12 Oct 2018 03:25:43 GMT

You are welcome!

Next time, if you have the question, please create the question post by yourself, we will help you directly in your own post.

Have a great day,
Kerry