ds402: Support checking the homing status. (#248)

Implement a new method BaseNode402.is_homed() which will switch to the corresponding operation mode HOMING and then examine the Statusword for the homing status bits. This allows to skip the homing procedure in case the drive controller still knows its position, but e.g. the Python application was restarted. Co-authored-by: André Filipe Silva <[email protected]>
christiansandberg · Aug 2, 2021 · 179022c · 179022c
1 parent 509f553
commit 179022c
Showing 1 changed file with 15 additions and 0 deletions.
diff --git a/canopen/profiles/p402.py b/canopen/profiles/p402.py
@@ -274,6 +274,21 @@ def is_faulted(self):
         bitmask, bits = State402.SW_MASK['FAULT']
         return self.statusword & bitmask == bits
 
+    def is_homed(self, restore_op_mode=False):
+        """Switch to homing mode and determine its status."""
+        previous_op_mode = self.op_mode
+        if previous_op_mode != 'HOMING':
+            logger.info('Switch to HOMING from %s', previous_op_mode)
+            self.op_mode = 'HOMING'
+        homingstatus = None
+        for key, value in Homing.STATES.items():
+            bitmask, bits = value
+            if self.statusword & bitmask == bits:
+                homingstatus = key
+        if restore_op_mode:
+            self.op_mode = previous_op_mode
+        return homingstatus in ('TARGET REACHED', 'ATTAINED')
+
     def homing(self, timeout=TIMEOUT_HOMING_DEFAULT, set_new_home=True):
         """Function to execute the configured Homing Method on the node
         :param int timeout: Timeout value (default: 30)