From 903ea1c1138426f5e9038366a52a0dad3eaadbe9 Mon Sep 17 00:00:00 2001
From: "Jonas A. Krieger" <jonas.krieger@psi.ch>
Date: Thu, 21 May 2026 10:31:16 +0200
Subject: [PATCH] updates calculation of offset calibrated field magnitude Babs

---
 cfg/main/flamemag_cfg.py | 16 ++++++++--------
 frappy_psi/cryoltd.py    | 40 +++++++++++++++++++++++-----------------
 2 files changed, 31 insertions(+), 25 deletions(-)

diff --git a/cfg/main/flamemag_cfg.py b/cfg/main/flamemag_cfg.py
index 60161336..3ec49a33 100644
--- a/cfg/main/flamemag_cfg.py
+++ b/cfg/main/flamemag_cfg.py
@@ -41,7 +41,7 @@ Mod('B',
 )
 
 Mod('Bx',
-    'frappy_psi.cryoltd.ComponentField',
+    'frappy_psi.cryoltd.CorrectedField',
     'magnetic field x component',
     channel='VMX',
     main='main',
@@ -55,10 +55,11 @@ Mod('Bx',
         max=23.0,
     ),
     tolerance=1.0,
+    offset=0.0,
 )
 
 Mod('By',
-    'frappy_psi.cryoltd.ComponentField',
+    'frappy_psi.cryoltd.CorrectedField',
     'magnetic field y component',
     channel='VMY',
     main='main',
@@ -72,10 +73,11 @@ Mod('By',
         max=22.9,
     ),
     tolerance=1.0,
+    offset=0.0,
 )
 
 Mod('Bz',
-    'frappy_psi.cryoltd.ComponentField',
+    'frappy_psi.cryoltd.CorrectedField',
     'magnetic field z component',
     channel='VMZ',
     main='main',
@@ -89,6 +91,7 @@ Mod('Bz',
         max=33.6,
     ),
     tolerance=1.0,
+    offset=0.0,
 )
 
 Mod('compressorA',
@@ -225,13 +228,10 @@ Mod('T_main_switch',
     main='main',
 )
 
-Mod('Calib',
-    'frappy_psi.cryoltd.Absfield', '',
+Mod('Babs',
+    'frappy_psi.cryoltd.AbsField', '',
     main='B',
     bx='Bx',
     by='By',
     bz='Bz',
-    bx_offset=0.0,
-    by_offset=0.0,
-    bz_offset=0.0,
 )
diff --git a/frappy_psi/cryoltd.py b/frappy_psi/cryoltd.py
index 2db87cd7..6506a17b 100644
--- a/frappy_psi/cryoltd.py
+++ b/frappy_psi/cryoltd.py
@@ -604,7 +604,26 @@ class Compressor(Channel, Drivable):
         self.sendcmd('Set:Compressor:Reset <CH>')
         self._error_text = ''
 
-class Absfield(Readable):
+class CorrectedField(ComponentField):
+    """
+    A component field, that keeps track of a calibration offset
+    """
+    offset = Parameter('hysteresis offset=raw value - corrected value', FloatRange(unit='G'),
+                       readonly=False, default=0.0)
+    corrected = Parameter('corrected value', FloatRange(unit='G'),
+                        default=0.0)
+    
+    
+    # def read_value(self):
+    #     value = super().read_value()
+    #     self.corrected = value - self.offset
+    #     return value
+    
+    def read_corrected(self):
+        return self.value- self.offset
+
+
+class AbsField(Readable):
     """
     Keep track of the magnet hysteresis and provide corrected readbacks
     """
@@ -613,22 +632,9 @@ class Absfield(Readable):
     by = Attached()
     bz = Attached()
 
-    bx_offset = Parameter('Hysteresis offset for Bx', FloatRange(unit='G'),
-                          readonly=False, default=0.0)
-    by_offset = Parameter('Hysteresis offset for By', FloatRange(unit='G'),
-                          readonly=False, default=0.0)
-    bz_offset = Parameter('Hysteresis offset for Bz', FloatRange(unit='G'),
-                          readonly=False, default=0.0)
-
-
-    calib_bx = Parameter('hysteresis-corrected Bx', FloatRange(unit='G'))
-    calib_by = Parameter('hysteresis-corrected By', FloatRange(unit='G'))
-    calib_bz = Parameter('hysteresis-corrected Bz+B', FloatRange(unit='G'))
+    Blong = Parameter('hysteresis-corrected Bz+B', FloatRange(unit='G'))
     value = Parameter('hysteresis-corrected total magnitude of the field', FloatRange(unit='G'))
 
     def read_value(self):
-        self.calib_bx = self.bx.value - self.bx_offset
-        self.calib_by = self.by.value - self.by_offset
-        self.calib_bz = self.bz.value+self.main.value - self.bz_offset
-
-        return sqrt(self.calib_bz ** 2 + self.calib_by** 2 + self.calib_bx** 2)
+        self.Blong = self.bz.corrected+self.main.value
+        return sqrt(self.Blong ** 2 + self.by.corrected** 2 + self.bx.corrected** 2)