I can only see printf() output, Cannot see NRF_LOG_INFO() output

[StevenW807]

I'm editing the Github example [ble_app_uart__saadc_timer_driven__scan_mode] . I'm using: 

- nRF52 DK (nRF52832)

- SEGGER

- SDK: nRF5_SDK_17.0.2_d674dde

- SoftDevice: s132_nrf52_7.2.0_softdevice.hex

- PuTTY

For this demo example, I can only see printf() output, cannot see NRF_LOG_INFO() output. 

I have checked that: 

1. NRF_LOG_INFO() and printf() works well in other demo codes

2. sdk_config.h setting

NRF_LOG_BACKEND_RTT_ENABLED 1

NRF_LOG_ENABLED 1

NRFX_UART_ENABLED 1 

UART_ENABLED 1

APP_UART_ENABLED 1

Please help, thanks! 

[StevenW807]

Can I ask why in this example, only RTT Viewer works for NRF_LOG_INFO() outputs well, please? i.e. Why PuTTY can only display printf() output, but PuTTY cannot display NRF_LOG_INFO() outputs? 

Thanks