rossmann-engineering/EasyModbusTCP.NET

Performance issues on Linux / NET5 because of System.IO.Ports

sandervandegeijn opened this issue · 2 comments

sandervandegeijn commented

As reported over here: dotnet/runtime#2379

When using on Linux / .NET core 5 (not formally supported yet, still it works) the cpu usage of Modbus RTU is terrible, barely usable. I'm talking half a core to do 3 requests/sec to some slave devices. The implementation of System.IO.Ports is not good, which is not a problem on WIndows (no cpu usage at all), but on Linux it goes through the roof.

Testing / using it: https://github.com/neographikal/Modbus2Mqtt

ict-one-nl commented

I switched out the default implementation with the Mono implementation, but on Windows this resulted in non functional serial communication.

elclaudio commented

hi
Could you explain how to set it up to compile and run the examples on http://easymodbustcp.net/codesampleseasymodbustcp-net ?
I'm trying to compile and run them on a raspberry pi 4 which should poll a modbus slave. I could not choose net5 and if I select framework 4, it compile, but when I run it under linux it crash:
Unhandled Exception: System.TimeoutException: No Response from Modbus Slave at EasyModbus.ModbusClient.ReadHoldingRegisters (System.Int32 startingAddress, System.Int32 quantity) [0x00817] in <8140caba19fe49389617683c5fa07156>:0 at EasyModbus.ModbusClient.ReadHoldingRegisters (System.Int32 startingAddress, System.Int32 quantity) [0x00831] in <8140caba19fe49389617683c5fa07156>:0 at EasyModbus.ModbusClient.ReadHoldingRegisters (System.Int32 startingAddress, System.Int32 quantity) [0x00831] in <8140caba19fe49389617683c5fa07156>:0 at EasyModbus.ModbusClient.ReadHoldingRegisters (System.Int32 startingAddress, System.Int32 quantity) [0x00831] in <8140caba19fe49389617683c5fa07156>:0 at modbustest3.Program.Main (System.String[] args) [0x00043] in <28b1a9dd07c24554a2210d774c0a8882>:0 [ERROR] FATAL UNHANDLED EXCEPTION: System.TimeoutException: No Response from Modbus Slave at EasyModbus.ModbusClient.ReadHoldingRegisters (System.Int32 startingAddress, System.Int32 quantity) [0x00817] in <8140caba19fe49389617683c5fa07156>:0 at EasyModbus.ModbusClient.ReadHoldingRegisters (System.Int32 startingAddress, System.Int32 quantity) [0x00831] in <8140caba19fe49389617683c5fa07156>:0 at EasyModbus.ModbusClient.ReadHoldingRegisters (System.Int32 startingAddress, System.Int32 quantity) [0x00831] in <8140caba19fe49389617683c5fa07156>:0 at EasyModbus.ModbusClient.ReadHoldingRegisters (System.Int32 startingAddress, System.Int32 quantity) [0x00831] in <8140caba19fe49389617683c5fa07156>:0 at modbustest3.Program.Main (System.String[] args) [0x00043] in <28b1a9dd07c24554a2210d774c0a8882>:0

The test app work under windows just fine, but I need it to run under linux !