CPU I/O High Load when using Modbus RTU

[jmir]

Hi,

We've a LM which communicates with 8 modbus 485, there are any scripts running and nothing... 

When RTU is enabled CPU/IO rises to 2 or 3 most of the time... Is it normal?

Firmware: 20230612
RTU 2 - 19200 - N/8/1 - HalfDuplex
8 slaves (4 wiith poll time 5s and 4 every 10s)

Thanks.