MODBUS
Posted: Sat Apr 30, 2022 10:17 am
Hi
A general question
I have used Modbus many years ago so i know the general operation but have a question
Roughly how fast (order of magnitude) can i poll the slave and read back multiple 16bit holding registers (approx 16) from the ECIO using the set up below
The hardware i am using is
windows 11 7 core processor & APP developer
ECIO40P16 dspic
For fastest speed should i use serial RTU via the coms port or TCP/IP or ? (coms port would be easier for me if not much slower than TCP/IP ?)
The reason i ask is that the ECIO is monitoring and manipulating I/O ports locally continuously (ie micro seconds) ie very fast and i do not wish a
poll request to slow down this action as i could lose data whilst data is being sent backward / forward from slave to APP developer
Perhaps some interrupt philosophy could be used to help to interlace the relatively slow communication between the APP developer and the ECIO
fast local port monitoring and control any rough ideas or so
So before i start testing this in a hardware implementation on my bench any general hints / advice
Note i do realise that modbus is not the fastest protocol nowadays but for other reasons i would like to use it in this case
Best regards
David
A general question
I have used Modbus many years ago so i know the general operation but have a question
Roughly how fast (order of magnitude) can i poll the slave and read back multiple 16bit holding registers (approx 16) from the ECIO using the set up below
The hardware i am using is
windows 11 7 core processor & APP developer
ECIO40P16 dspic
For fastest speed should i use serial RTU via the coms port or TCP/IP or ? (coms port would be easier for me if not much slower than TCP/IP ?)
The reason i ask is that the ECIO is monitoring and manipulating I/O ports locally continuously (ie micro seconds) ie very fast and i do not wish a
poll request to slow down this action as i could lose data whilst data is being sent backward / forward from slave to APP developer
Perhaps some interrupt philosophy could be used to help to interlace the relatively slow communication between the APP developer and the ECIO
fast local port monitoring and control any rough ideas or so
So before i start testing this in a hardware implementation on my bench any general hints / advice
Note i do realise that modbus is not the fastest protocol nowadays but for other reasons i would like to use it in this case
Best regards
David