diff --git a/cfg/main/ma10.cfg b/cfg/main/ma10.cfg
index 262a7f1..8a09a12 100644
--- a/cfg/main/ma10.cfg
+++ b/cfg/main/ma10.cfg
@@ -67,5 +67,6 @@ uri = ma10-ts.psi.ch:3004
 description = stick rotation
 class = secop_psi.phytron.Motor
 io = om_io
+sign = -1
 encoder_mode = CHECK
 
diff --git a/cfg/stick/ma10stick.cfg b/cfg/stick/ma10stick.cfg
index 948114e..0fa393e 100644
--- a/cfg/stick/ma10stick.cfg
+++ b/cfg/stick/ma10stick.cfg
@@ -10,7 +10,7 @@ service = stick
 
 [ts]
 class = secop_psi.sea.SeaReadable
-iodev = sea_stick
+io = sea_stick
 sea_object = tt
 json_file = ma10.config.json
 rel_paths = ts
diff --git a/secop_psi/phytron.py b/secop_psi/phytron.py
index 13cb70b..805c940 100644
--- a/secop_psi/phytron.py
+++ b/secop_psi/phytron.py
@@ -60,7 +60,8 @@ class Motor(PersistentMixin, HasIO, Drivable):
     speed = Parameter('', FloatRange(0, 20, unit='deg/s'), readonly=False)
     accel = Parameter('', FloatRange(2, 250, unit='deg/s/s'), readonly=False)
     encoder_tolerance = Parameter('', FloatRange(unit='deg'), readonly=False, default=0.01)
-    zero = PersistentParam('', FloatRange(unit='deg'), readonly=False, default=0)
+    offset = PersistentParam('', FloatRange(unit='deg'), readonly=False, default=0)
+    sign = PersistentParam('', IntRange(-1,1), readonly=False, default=1)
     encoder = Parameter('encoder reading', FloatRange(unit='deg'))
     sameside_offset = Parameter('offset when always approaching from the same side',
                                 FloatRange(unit='deg'), readonly=False, default=0)
@@ -86,7 +87,7 @@ class Motor(PersistentMixin, HasIO, Drivable):
 
     def read_value(self):
         prev_enc = self.encoder
-        pos = float(self.get('P20R')) + self.zero
+        pos = float(self.get('P20R')) * self.sign - self.offset
         if self.encoder_mode != 'NO':
             enc = self.read_encoder()
         else:
@@ -111,7 +112,7 @@ class Motor(PersistentMixin, HasIO, Drivable):
         else:
             if self._sameside_pending:
                 # drive to real target
-                self.set('A', self.target - self.zero)
+                self.set('A', self.sign * (self.target + self.offset))
                 self._sameside_pending = False
                 return pos
             if (self.encoder_mode == 'CHECK' and
@@ -131,7 +132,7 @@ class Motor(PersistentMixin, HasIO, Drivable):
     def read_encoder(self):
         if self.encoder_mode == 'NO':
             return self.value
-        return float(self.get('P22R')) + self.zero
+        return float(self.get('P22R')) * self.sign - self.offset
 
     def read_speed(self):
         return float(self.get('P14R')) / self.speed_factor
@@ -158,14 +159,14 @@ class Motor(PersistentMixin, HasIO, Drivable):
             # drive first to target + sameside_offset
             # we do not optimize when already driving from the right side
             self._sameside_pending = True
-            self.set('A', value - self.zero + self.sameside_offset)
+            self.set('A', self.sign * (value + self.offset + self.sameside_offset))
         else:
-            self.set('A', value - self.zero)
+            self.set('A', self.sign * (value + self.offset))
         self.setFastPoll(True, self.fast_poll)
         return value
 
-    def write_zero(self, value):
-        self.zero = value
+    def write_offset(self, value):
+        self.offset = value
         self.saveParameters()
         return Done
 
@@ -177,16 +178,16 @@ class Motor(PersistentMixin, HasIO, Drivable):
         """reset error, set position to encoder"""
         self.read_value()
         if self.status[0] == self.Status.ERROR:
-            enc = self.encoder - self.zero
-            pos = self.value - self.zero
+            enc = self.encoder + self.offset
+            pos = self.value + self.offset
             if abs(enc - pos) > self.encoder_tolerance:
                 if enc < 0:
                     while enc < 0:
-                        self.zero -= 360
+                        self.offset += 360
                         enc += 360
-                    self.set('P22S', enc)
+                    self.set('P22S', enc * self.sign)
                     self.saveParameters()
-                self.set('P20S', enc)  # set pos to encoder
+                self.set('P20S', enc * self.sign)  # set pos to encoder
             self.read_value()
         # self.status = self.Status.IDLE, ''