Thank you very much for the answer answer.
Where can I find this file?
...after modifying the `modbus_rtu.py' in the following way...
I'm using Raspbian, tried to find and replace the code in these files:
pi@rpiplc00 / $ sudo find / -name "modbus_rtu.py" -print
/home/pi/distr/modbustk/modbus_tk/modbus_rtu.py
/home/pi/distr/modbustk/build/lib.linux-armv6l-2.7/modbus_tk/modbus_rtu.py
but it didn't reduce CPU load.
Cheers.
