Re: Plus/4 RS232 woes

From: smf <smf_at_null.net>
Date: Mon, 3 Sep 2018 18:20:47 +0100
Message-ID: <b3f8e0a1-9a43-9fcf-04b0-eedc258fc279@null.net>
On 03/09/2018 15:46, Gerrit Heitsch wrote:
> I only know about CTS being broken, it will turn off the transmitter 
> in the middle of a byte and that's why the CTS line of the 6551 in the 
> Plus/4 is connected to GND.
>
It's not so much broken as doesn't mean what the majority want it to.

If you're using RS485 multidrop and you lose CTS then you need to stop 
sending immediately or you'll get a network collission, putting that 
logic in the UART was however a mistake.

> RTS is an output and tells the other side that you are ready to 
> receive data.

In half duplex world RTS it really means ready to send.

https://www.logic-control.com/datasheets/4/Tech%20Note/The%20Secrets%20of%20RS-485%20Half%20Duplex%20Communication.pdf
Received on 2018-09-03 20:01:05

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