bremenpl
Member level 3
Hello there,
On a university we are working on a project at the moment where RS485 communication is involved. We are designing everything from scratch so we can choose any protocol for the RS485 line. One of my friend is really insisting on Modbus RTU. I have not used it before, but I have used a custom RS485 protocol however. Going through the modbus rtu reference guide I could not fail to notice how obsolete this protocol is. My main problem with it is that it is heavily time based (one has to count 3.5 char times at the begining/end and 1.5 char times between the data). Because of this fact I am not allowed to use DMA for the incomming data stream, as I have to count 1.5 char time (and waste an additional timer) each received byte.
Also there are only read/ write registers or coils commands allowed, so I would have to build a higher layer framework anyways If I wanted to call some functions and etc. Making virtual registers addresses is also kind of odd for me...
So anyways, I was wondering either there is any serious competitor for the Modbus RTU (implemented on an RS485 line) that meets the modern age requirements.
I would appreciate all help.
On a university we are working on a project at the moment where RS485 communication is involved. We are designing everything from scratch so we can choose any protocol for the RS485 line. One of my friend is really insisting on Modbus RTU. I have not used it before, but I have used a custom RS485 protocol however. Going through the modbus rtu reference guide I could not fail to notice how obsolete this protocol is. My main problem with it is that it is heavily time based (one has to count 3.5 char times at the begining/end and 1.5 char times between the data). Because of this fact I am not allowed to use DMA for the incomming data stream, as I have to count 1.5 char time (and waste an additional timer) each received byte.
Also there are only read/ write registers or coils commands allowed, so I would have to build a higher layer framework anyways If I wanted to call some functions and etc. Making virtual registers addresses is also kind of odd for me...
So anyways, I was wondering either there is any serious competitor for the Modbus RTU (implemented on an RS485 line) that meets the modern age requirements.
I would appreciate all help.