From: W. Trevor King <wking@drexel.edu>
Date: Tue, 19 Apr 2011 17:51:17 +0000 (-0400)
Subject: Set `axis = ...` earlier in AFM.move_just_onto_surface().
X-Git-Tag: v0.3~13
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=bdc857f31b48bbb9a6f704079f9898bad4820a53;p=pyafm.git

Set `axis = ...` earlier in AFM.move_just_onto_surface().
---

diff --git a/pyafm.py b/pyafm.py
index 7ef3a85..c16b0b8 100644
--- a/pyafm.py
+++ b/pyafm.py
@@ -66,11 +66,13 @@ class AFM (object):
         LOG.info('moving to %g onto the surface' % depth)
 
         stepper_tolerance = 2*self.stepper.step_size
+
+        axis = self.piezo.axis_by_name(self.axis_name)
+
         zero = _convert_volts_to_bits(axis.axis_channel_config, 0)
         target_def = _convert_volts_to_bits(axis.channel_config, setpoint)
 
         LOG.debug('zero the %s piezo output' % self.axis_name)
-        axis = self.piezo.axis_by_name(self.axis_name)
         self.piezo.jump(axis_name=self.axis_name, position=zero)
 
         LOG.debug("see if we're starting near the surface")