ultrasound: change control roi0 to a Readable (2)

+ remove cfg/PEUS.py
+ fix equipment_id of PEUS
+ add header to frappy_psi.iqplot

frappy_psi/ultrasound.py

@@ -83,10 +83,8 @@ class Roi(Readable):
         return Done
 
 
-class ControlRoi(Roi, Writable):
+class ControlRoi(Roi, Readable):
     freq = Attached()
-    # target is not releavnt -> always moving to I to zero
-    target = Parameter(datatype=Roi.value.datatype, export=False)
     maxstep = Parameter('max frequency step', FloatRange(unit='Hz'), readonly=False,
                         default=10000)
     minstep = Parameter('min frequency step for slope calculation', FloatRange(unit='Hz'),
@@ -122,10 +120,6 @@ class ControlRoi(Roi, Writable):
         elif self.control_active:
             self._freq_target = self.freq.write_target(clamp(freq - self.maxstep, newfreq, freq + self.maxstep))
 
-    def write_target(self, value):
-        self.control_active = True
-        return 0
-
 
 class Pars(Module):
     description = 'relevant parameters from SEA'