Current status: 
Laser busy signal works correctly (5V if the grating moves, 0V if not) if the laser is operated by the Sirah software.

When the laser is controled by the "Thorium Main VI" the laser busy signal is always 0V.

Solution for a working laser busy / dye out signal was to disable the FCU and set the FCU status to "False" (see attached picture).

Remark: FCU unit will not be used for Bismuth experiment!

I changed the laser step complete cabling from a quad coinc (see attached picture) to a Logic Fan In / Fan out (same as laser scan complete).
The "detour" through the quad coinc yielded to a very short laser step complete signal of ~500ns...

Due to the change it is now ~15µs long and has the same length as the laser scan complete signal (~15µs).

There is still no Beam in the ESR.

The beam is currently at TE3 - between SIS and ESR

Carrier frequency:244MHz
IQ rate: 10M Samples/seconds
Reference level: -25
RF-Attenuation(dB):40
IF-Attenuation(dB):19.9288
Samples/Record:2^18=262144
Records/File:2^12=4096
Masterpath:p:\208Bi\iq\IQ_2022-05-10_17-06-29
           p:\208Bi\sc\IQ_2022-05-10_17-06-29
Free space of hard disk: 34.9TB.

"Laser step complete" and "laser scan complete" are working again.

Problems:
1) Connections were wrong in the Software. 
2) Sometimes the connection to "laser scan complete" was lost (Wackelkontakt).
3) The VI was initialized with the wrong LabJack Channels.

Now:
1) fixed connections in the software.
2) switch to an other "channel" of the LabJack device for "laser scan complete".
3) The channels in the Cobra VI are for...
laser scan complete -> Channel 5
laser step complete -> 6

We definetely should keep an eye and check frequently the signals, that we do not have a lost connection (Wackelkontakt) again of these 2 channels.

We found a "Bug" in the control of the Sirah dye system.

Due that we don't use the FCU and the temperature control unit we could not start the Sirah software without getting numerous errors. 
The fix was to plug in the BBO oven again, move the FCU to "origin", than move to a specific location that the FCU goes in an "idle" mode. 
Than the Sirah software can be started again without getting erros. 

It is now possible to stabilize and move the laser with both stages.

The software and hardware settings are attached.
For synchronizing with the laser pulse we use following frequency generator settings:
period: 200us
high: 5V
low: 0V
duty: 50% 

The frequency generator is triggered with the external Q-switch trigger signal, that is in coincidence with the ESR HF.
To use the stabilization one has to use the external and NOT the q-switch mode of the laser.