Multi-sample workflow raise exception while driving att in the setSafeAttenuation()

[2010-06-20 00:11:35] Driving attenuator to 90 degree ...
[2010-06-20 00:11:47] Attenuator is now at 90 degree
[2010-06-20 00:11:47] Start histmem ...
[2010-06-20 00:12:08] Histmem stopped
[2010-06-20 00:12:08] Current rate: 0.960399985313
[2010-06-20 00:12:09] Driving attenuator to 60 degree ...
[2010-06-20 00:12:21] Attenuator is now at 60 degree
[2010-06-20 00:12:21] Start histmem ...
[2010-06-20 00:12:33] Histmem stopped
[2010-06-20 00:12:33] Current rate: 0.0
[2010-06-20 00:12:34] Driving attenuator to 30 degree ...
ERROR:root:Exception occured. It will now go to clean up mode.
Traceback (most recent call last):
  File "C:\DOCUME~1\quokka\LOCALS~1\Temp\jep7820661136532446515.py", line 238, in <module>
    workflow.runQuokkaScan(acqusitionEntries)
  File "C:/Program Files/GumTree/quokka1.4.6/scripts\gumpy\quokka\workflow.py", line 84, in runQuokkaScan
    runMultiConfigScan(acquisitionGroup)
  File "C:/Program Files/GumTree/quokka1.4.6/scripts\gumpy\quokka\workflow.py", line 136, in runMultiConfigScan
    runScattering(acqEntries, configSetting)
  File "C:/Program Files/GumTree/quokka1.4.6/scripts\gumpy\quokka\workflow.py", line 182, in runScattering
    setSafeAttenuation(configSetting['startingAttenuation'])
  File "C:/Program Files/GumTree/quokka1.4.6/scripts\gumpy\quokka\quokka.py", line 119, in setSafeAttenuation
    driveAtt(attenuationLevels[level])
  File "C:/Program Files/GumTree/quokka1.4.6/scripts\gumpy\quokka\quokka.py", line 100, in driveAtt
    sics.drive('att', value)
  File "C:/Program Files/GumTree/quokka1.4.6/scripts\gumpy\commons\sics.py", line 72, in drive
    device.drive(float(value))
SicsExecutionException: org.gumtree.gumnix.sics.io.SicsExecutionException: ERROR: somebody else is still driving, Request rejected
(<class 'jep.SicsExecutionException'>, SicsExecutionException('org.gumtree.gumnix.sics.io.SicsExecutionException: ERROR: somebody else is still driving, Request rejected',), <traceback object at 0x43EF7788>)

Clean up
[2010-06-20 00:12:35] Driving attenuator to 330 degree ...
<class 'jep.SicsExecutionException'>: org.gumtree.gumnix.sics.io.SicsExecutionException: ERROR: somebody else is still driving, Request rejected