RE #26846 Fixed instrument issue with MantidPlot

scripts/Engineering/gui/engineering_diffraction/engineering_diffraction.py

@@ -50,7 +50,7 @@ class EngineeringDiffractionGui(QtWidgets.QMainWindow, Ui_main_window):
         self.lineEdit_RBNumber.textChanged.connect(slot)
 
     def set_on_instrument_changed(self, slot):
-        self.comboBox_instrument.currentTextChanged.connect(slot)
+        self.comboBox_instrument.currentIndexChanged.connect(slot)
 
     def open_help_window(self):
         InterfaceManager().showCustomInterfaceHelp(self.doc)

scripts/Engineering/gui/engineering_diffraction/tabs/calibration/presenter.py

@@ -46,6 +46,12 @@ class CalibrationPresenter(object):
         self.disable_calibrate_buttons()
 
     def set_instrument_override(self, instrument):
+        if instrument == 0:
+            instrument = "ENGINX"
+        elif instrument == 1:
+            instrument = "IMAT"
+        else:
+            raise ValueError("Invalid instrument index")
         self.view.set_instrument_override(instrument)
         self.instrument = instrument