post-p21592 HVE commissioning cleanup

beamline/undulator.py

@@ -1,4 +1,6 @@
+import time
 from time import sleep
+
 import numpy as np
 from epics import PV
 
@@ -21,7 +23,7 @@ N_UNDS = list(range(3, 15 + 1))
 # Cristallina without calibration
 # offset is the difference between PSSS and undulator setpoint 
 # sign convention: Undulator - PSSS 
-energy_offset = -62 # eV
+energy_offset = -59 # eV
 
 
 # move the PSSS motor according to the energy
@@ -390,9 +392,19 @@ class ScalerEK:
 
 
 def get_machine_n_und_ref():
-    res = PVEnumAdjustable("SARUN:REF-UND").get()
-    if not res.startswith("SARUN"):
-        return None
+
+    for attempt in range(3):
+        try:
+            res = PVEnumAdjustable("SARUN:REF-UND").get()
+            if not res.startswith("SARUN"):
+                return None
+        except AttributeError as e:
+            print("Error getting undulator, retrying")
+            print(e)
+            time.sleep(1)
+        else:
+            break
+
     n = len("SARUN")
     res = res[n:]
     try: