first tries with uniax stick

Change-Id: I70da38aff091f7fc64f409485db335cde07163c9

cfg/trinamic.cfg

@@ -23,4 +23,3 @@ speed=40
 encoder_tolerance=3.6
 free_wheeling=0.1
 power_down_delay=0.1
-# pull_up=1

secop_psi/trinamic.py

@@ -127,9 +127,7 @@ class Motor(PersistentMixin, HasIodev, Drivable):
     fast_pollfactor = 0.001  # poll as fast as possible when busy
     _started = 0
     _calcTimeout = True
-    _need_reset = False
-    _save_filename = None
-    # _try_count = 0
+    _need_reset = None
 
     def comm(self, cmd, adr, value=0, bank=0):
         """set or get a parameter
@@ -229,13 +227,18 @@ class Motor(PersistentMixin, HasIodev, Drivable):
             writeDict = self.loadParameters()
             self.log.info('set to previous saved values %r', writeDict)
             # self.encoder now contains the last known (persistent) value
-            self.fix_encoder(encoder)
+            if self._need_reset is None:
+                if self.status[0] == self.Status.IDLE:
+                    # server started, power cycled and encoder value matches last one
+                    self.reset()
+            else:
+                self.fix_encoder(encoder)
+                self._need_reset = True
+                self.status = self.Status.ERROR, 'power loss'
+                # or should we just fix instead of error status?
+                # self.set('steppos', self.steppos - self.zero, check=False)
             self.comm(SET_GLOB_PAR, 255, 1, bank=2)  # set initialized flag
             self._started = 0
-            self._need_reset = True
-            self.status = self.Status.ERROR, 'power loss'
-            # or should we just fix instead of error status?
-            # self.set('steppos', self.steppos - self.zero, check=False)
 
         return encoder if abs(encoder - steppos) > self.tolerance else steppos