enable MCS

I use a ZCU102 board with the ADRV9009 evaluation board. When I check my oscilloscope, I only see one sysref pulse when I turn the board on.

I think I have enable the "TALISE_enableMultichipSync" function from UG-1295 p54:

root@zynqmp:/sys/kernel/debug/iio/iio:device2# cat adi,fhm-mode-enable-mcs-sync
0
root@zynqmp:/sys/kernel/debug/iio/iio:device2# echo 1 > adi,fhm-mode-enable-mcs-sync
root@zynqmp:/sys/kernel/debug/iio/iio:device2# cat adi,fhm-mode-enable-mcs-sync
1
root@zynqmp:/sys/kernel/debug/iio/iio:device2# echo 1 > adi,fhm-mode-enable-mcs-sync
root@zynqmp:/sys/kernel/debug/iio/iio:device2# cat adi,fhm-mode-enable-mcs-sync
1

But I don't see any SYSREF pulses, on my oscilloscope. This should reset the state machine and I expects the multichip sync sequence to start over like UG-1295 suggested.

Then I tried to add a iio_sysfs_trigger,but also without succes:
wiki.analog.com/.../iio-trig-sysfs

root@zynqmp:/sys/bus/iio/devices/iio_sysfs_trigger# echo 0 > add_trigger
root@zynqmp:/sys/bus/iio/devices/trigger0# echo 1 > trigger_now
root@zynqmp:/sys/bus/iio/devices/iio_sysfs_trigger# echo 1 > add_trigger
root@zynqmp:/sys/bus/iio/devices/trigger1# echo 1 > trigger_now

Is it possible to enable mcs trough the virtual file system? How should I proceed to get the 4 sysref pulses to be carried out? Should I try to modify de registries directly of the AD9528?