Fix negative current bug

Hsuan-Tung Peng · Hsuan-Tung Peng · commit 2268980594fa · 2018-08-22T11:23:15.000-04:00
diff --git a/lightlab/equipment/lab_instruments/Keithley_2400_SM.py b/lightlab/equipment/lab_instruments/Keithley_2400_SM.py
@@ -74,7 +74,10 @@ def setCurrentMode(self, protectionVoltage=1):
 
     def _configCurrent(self, currAmps):
         currAmps = float(currAmps)
-        currAmps = np.clip(currAmps, a_min=1e-6, a_max=1.)
+        if currAmps >= 0:
+            currAmps = np.clip(currAmps, a_min=1e-6, a_max=1.)
+        else:
+            currAmps = np.clip(currAmps, a_min=-1, a_max=-1e-6)
         if currAmps != 0:
             needRange = 10 ** np.ceil(np.log10(abs(currAmps)))
             self.setConfigParam('SOURCE:CURR:RANGE', needRange)
