Support for RS485 on Duet 6XD and 6HC
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Re: Does Duet 6XD support RS485 communication
Currently RRF version 3.5.2 does not directly support RS485 Serial Data communications ( or RS485 MODBUS RTU ) . It supports UART type serial communications
@dc42 , did mention that support was coming soon in RRF 3.6.0 but that seems to have been revised to "After 3.6.0 ".
Since Duet dev is not delivering on this RS485 support , i am currently looking for alternatives on how to accomplish the bidirectional communications between Duet 6XD and a Mitsubishi PLC with RS485 Adapter(FX3u-485ADP-MB) which has 60+ SMT PnP Electric Feeders connected to it
Duet 6XD ( Port IO0 -- UART ) <===> RS485 Adapter on PLC ( FX3u-485-MB) <===> Controlling SMT PnP Electric Feeders
Do i need a UART TTL to RS485 Two-Way Converter to accomplish this Since there is no direct support for RS485 in RRF ?
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@developeralgo222 Modbus RTU support will require both hardware and software support. Future revisions of some Duet 3 boards will include RS485 interfaces. Other Duet 3 boards will need an external 3.3V to RS485 converter and probably a spare IO_OUT pin to control the transmission direction. Software support for Duet 3 boards will be added to RRF either in version 3.6 or shortly afterwards.
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@dc42 is there any Alternative while i wait for a stable solution. I have 60+ Electric feeders that i need working in 4 days for a client production job ? Any suggestions on a RS485 converter to get if required and the wiring connections that for the time being can accomplish this
My Older discussion is here : https://forum.duet3d.com/topic/35524/does-duet-6xd-support-rs485-communication/5?_=1719243430041
Since there is no specific timeline for RS485 Support in RRF at the moment
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Currently with existing boards Would such a TTL (UART) to RS485 Converter Compatible with 3.3V and 5.0V signals work plus Spare IO (IO0 or IO1 ) port on Duet 6XD
With such wiring considering your suggestions :
Simple wiring picture
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@developeralgo222 yes that board looks good, although it's more complicated than RS485 boards that I have used before.
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@dc42 As for communications commands from Duet 6XD to the electric feeder using the above setup ( RS485 Converter + IO0 Port ) . Can you please elaborate using RRF 3.5.2 commands with an example of a simple communication ?
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@dc42, @T3P3Tony ,@droftarts Also what is the Maximum UART Port Speed that IO0 or IO1 can handle on Duet 6XD since i think default UART clock is 3MHz but Apparently UART CLOCK can go as high as 100MHZ. The maximum baud rate is clock/16.
So what is the Maximum Speed of UART Port on Duet 6XD without corruption of data ? 115200 bps ?
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@developeralgo222 maximum transmission speed is much higher than that. However, it you try to receive data above about 57600 baud then you may suffer character loss because of interrupt latency.