K8090 - 8 channel USB relay card, can't read input


I have a question about protocol communication between PC and usb relay card.

In K8090_ProtocolManual.pdf i don’t find a command to query the status of the board buttons.
I want use board buttons as inputs and I need to read the status.
I receive button status only in asynchronous way when i push/release button. Is there a way to get button status using a query command from PC ?

Thank you.