M2K adalm2000 m2k-dds

Looks like m2k-dds support has been added so with new firmware:

iio:device5: m2k-dds
                4 channels found:
                        altvoltage0: 1A (output)
                        5 channel-specific attributes found:
                                phase, value: 0
                                raw, value: 1
                                sampling_frequency, value: 75000000
                                frequency, value: 0
                                scale, value: 0.000000
                        altvoltage1: 1B (output)
                        5 channel-specific attributes found:
                                phase, value: 0
                                raw, value: 1
                                sampling_frequency, value: 75000000
                                frequency, value: 0
                                scale, value: 0.000000
                        altvoltage2: 2A (output)
                        5 channel-specific attributes found:
                                phase, value: 0
                                raw, value: 1
                                sampling_frequency, value: 75000000
                                frequency, value: 0
                                scale, value: 0.000000
                        altvoltage3: 2B (output)
                        5 channel-specific attributes found:
                                phase, value: 0
                                raw, value: 1
                                sampling_frequency, value: 75000000
                                frequency, value: 0
                                scale, value: 0.000000
                1 debug attributes found:
                        direct_reg_access, value: 0x90162

how are the altvoltage 0 - 3 outputs routed?

so I logged in the m2k and tried to see if I could get any output:

/sys/bus/iio/devices/iio:device5

#echo 10000 > out_altvoltage0_1A_frequency

#echo 1 > out_altvoltage0_1A_scale

but didn't see any output - if anyone knows how to get this to work it would be most appreciated maybe even a python example, as this looks like it could provide a glitch free frequency sweep on the m2k.

Thanks,

John