UART 1 can not work properly

Follow the tutorials on the web ,and install serial port tools ,Cutecom . DEVICE select /dev/ttyTHS0 , and enter characters in the ‘input’ box.
Test the UART 1 TX waveform with an oscilloscope , I can not get any waves.
I have checked the pinmux , the customer usage is UA3_TX/RX.
The voltage is 3.3V . CTS and RTS not use.
Please give some advise about this case.

hello 863089782,

according to Jetson AGX Xavier Developer Kit User Guide,
you may use [J501] Micro-USB connector provides access to the UART console,
please also check booting messages for the register serial ports.
for example,

nvidia@nvidia-desktop:~$ dmesg | grep UART
[    1.714851] 3100000.serial: ttyTHS0 at MMIO 0x3100000 (irq = 51, base_baud = 0) is a TEGRA_UART
[    1.715936] 3110000.serial: ttyTHS1 at MMIO 0x3110000 (irq = 52, base_baud = 0) is a TEGRA_UART
[    1.717001] 3140000.serial: ttyTHS4 at MMIO 0x3140000 (irq = 53, base_baud = 0) is a TEGRA_UART