I tried to communicate between an RS-485 RTU-based Modbus master and slave, but I am getting the following error.

Using <2.50> user settings for compiler
Launching the compiler...
C:\ProgramData\MatrixTSL\FlowcodeV11\FCD\PIC\batch\pic_xc8_comp.bat "C:\Program Files\Microchip\xc8\v2.50\pic\bin ...

I tried to communicate between an RS-485 RTU-based Modbus master and slave, but I am getting the following error.

Using <2.50> user settings for compiler
Launching the compiler...
C:\ProgramData\MatrixTSL\FlowcodeV11\FCD\PIC\batch\pic_xc8_comp.bat "C:\Program Files\Microchip\xc8\v2.50\pic\bin ...

Communication works if the pull-up resistor is changed to 3 kiloohms. It is expected that this result is due to the threshold level. It appears that a pull-up resistor of about 2k ohms is necessary for stable communication.
The pink color is the waveform directly connected to the MCU, and the yellow ...

This seems to be about RS-485 terminator resistors.

Of course, I tried attaching 4.7K Ohm and 10K Ohm pull-up resistors, but the result is a communication failure.

The pink waveform is the waveform outputting "Test" from the PIC18F57Q84.

The second yellow waveform is the waveform outputting "Test" from another device (PC USB-Serial).

Hello.

I am trying to proceed with a project using the PIC18F57Q84. I had trouble because it wouldn't compile. After receiving advice on how to switch compilers, it now compiles successfully. However, UART communication is not working. When I checked with an oscilloscope, the waveform phase was ...

I don't have much time, so I decided to use a different MCU.

I will test it again later.

Thank you for your interest.

Here my file

Thank you

The MCLR signal is pulled up to 5V and connected to the MCU via a 100-ohm resistor.

I am uploading the hexadecimal file, which was compiled in FC11 and read from the downloaded file.

Thank you for your interest.

Here my hexa file.