fdMonitor only works sporadically

[jyijyi]

if you want to isolate whether this is related to legato API, you can simply use open(),read(),write() generic API to control the UART:

UART flow control with WP7608

Maybe you can run my sample application attached here. It will change the status of CTS every three seconds. It is working on my WP7608 FW R12.UART_Test1.rar (99.5 KB)