uniax, version 7.10.2021

- driving with a generator
- 3 phases
  1) find active range (low current, far movement until force over hysteresis)
  2) release force until well below target
  3) adjusting using pid_p. (this is in fact an integral factor)

secop_psi/trinamic.py

@@ -85,8 +85,10 @@ class Motor(PersistentMixin, HasIodev, Drivable):
                       1, ANGLE_SCALE, readonly=True, initwrite=False)
     target = Parameter('_', FloatRange(unit='$'), default=0)
 
-    movelimit = Parameter('max. angle to drive in one go', FloatRange(unit='$'),
-                          readonly=False, default=360, group='more')
+    move_limit = Parameter('max. angle to drive in one go when current above safe_current', FloatRange(unit='$'),
+                           readonly=False, default=5, group='more')
+    safe_current = Parameter('motor current allowed for big steps', FloatRange(unit='A'),
+                             readonly=False, default=0.2, group='more')
     tolerance = Parameter('positioning tolerance', FloatRange(unit='$'),
                           readonly=False, default=0.9)
     encoder_tolerance = HwParam('the allowed deviation between steppos and encoder\n\nmust be > tolerance',
@@ -262,8 +264,9 @@ class Motor(PersistentMixin, HasIodev, Drivable):
 
     def write_target(self, target):
         self.read_value()  # make sure encoder and steppos are fresh
-        if abs(target - self.encoder) > self.movelimit:
-            raise BadValueError('can not move more than %s deg' % self.movelimit)
+        if self.maxcurrent >= self.safe_current + CURRENT_SCALE and (
+                abs(target - self.encoder) > self.move_limit + self.tolerance):
+            raise BadValueError('can not move more than %s deg %g %g' % (self.move_limit, self.encoder, target))
         diff = self.encoder - self.steppos
         if self._need_reset:
             raise HardwareError('need reset (%s)' % self.status[1])
@@ -274,7 +277,7 @@ class Motor(PersistentMixin, HasIodev, Drivable):
                 raise HardwareError('need reset (encoder does not match internal pos)')
             self.set('steppos', self.encoder - self.zero)
         self._started = time.time()
-        self.log.info('move to %.1f', target)
+        self.log.debug('move to %.1f', target)
         self.comm(MOVE, 0, (target - self.zero) / ANGLE_SCALE)
         self.status = self.Status.BUSY, 'changed target'
         return target