digital waveform generation using NI6280 port0

I am trying to make use port 0 of my NI 6280 to generate digital waveform clocked using conter0 output. I need to generate 5 address bits to scan my pressure scanner,  00000  (port 0) to 11111(port 32) using conter 0 output as clock source. for each clock signal my outputs port 0 line 0:4 should change like 00000,00001,00010,00011....11111 and repeat this sequence till my clock source gives output. I have generated a counter task which generates 10khz output pulses on PFI12, and i want to give this PFI12 as clock source for my digital waveform generation on port 0. when i try to make a logic using digital output task, with timing source as counter 0 output, pfi 12, code gives an error saying port 0 is not free. subsequently i tried to use port 1, there i am getting an error , buffered operation is not supported. what might be the issue? how generate pulses clocked using counter 0 out as clock?