Modbus Master Speed

[viktor_au]

Hi
My questions are probably not the correct.... as I am not as advanced as you are.
However... As I understood (please correct me).
After Master_Local (Rs485) collects some information from different Slaves and save it to digi_inputs 08,09,10,11, and to Analog inputs 14_0 and 14_1...(etc),
The Slave for HMI monitor sends over Rs232 information to HMI Master (Xpanel).
Question.
What is the reason to use the HMI Master COM2: RS-232C but not the COM1: RS-422/485 ?

I read somewhere:
RS232 requires a minimum of 3 conductors to connect the two devices. Rx, Tx and Ground.
Some devices implement hardware handshaking. This means that before they send a message some voltage must be applied to one of the other pins on the port. If hardware handshaking is active on the device, then you will never get a response until you bypass it or implement it. We recommend bypassing it because there are often differences in the ways that vendors implemented it.

[seokgi]

Thank you for your interest.
I use 6 serial ports.

Serial 1 : External RS-485 Base Modbus RTU Master
Serial 2 : for GPS
Serial 3 : Local Board RS-485 Base Modbus RTU Master
Serial 4 : HMI RS-232 Base Modbus RTU Slave
Serial 5 : for between MCU Serial Communication
Serial 6 : for Monitoring System

SPI 1 : 2 each W5500 for Ethernet Modebus/TCP Slave

And Modbus RTU communication is handshaked within the library. So communication becomes easy. However, when calling multiple Modbus slave IDs in FC10, it slows down drastically. It's probably because of the delay time or timeout. But I can't modify the library.

The slave mode of Modbus/TCP is also very slow and causes many communication errors.

Thank you

[viktor_au]

Hi
Do you have problems in FC10 only?
Was any problems in FC8 or FC9?

[seokgi]

Sorry don't know.

[seokgi]

Should I just get on with it?

Please let me know how I can handle it.