Problem with driving IO pin with Flex900 on USRP

Hi All!

I tried to set RX_IO8-RX_IO15 pins to output on Flex900 board but

I used this code

m_u_rx->_write_oe(1, 0xff00, 0xff00);
m_u_rx->write_io(1, 0xff00, 0xff00);

where m_u_rx is an usrp_standard_rx_sptr object.

Applying an oscilloscope probe (or voltmeter) didn’t point to a value

But configuring its for input is ok, using this

m_u_rx->_write_oe(1, 0x0000, 0xff00);
int b = m_u_rx->read_io(1);

and placing pullup / pulldown resistor on pins lead to value change.

What’s wrong with the output part?