diff --git a/siriuspy/siriuspy/oscilloscope/scopes.py b/siriuspy/siriuspy/oscilloscope/scopes.py
index 720f507d5..c0963e40a 100644
--- a/siriuspy/siriuspy/oscilloscope/scopes.py
+++ b/siriuspy/siriuspy/oscilloscope/scopes.py
@@ -18,7 +18,7 @@ class ScopeSignals:
     """Mapping of physical signals to scope channels."""
 
     SI_FILL_PATTERN = (Scopes.AS_DI_FPMDIG, 5025, 'CHAN1')
-    BO_FILL_PATTERN = (Scopes.AS_DI_FPMDIG, 5025, 'CHAN2')
+    BO_FILL_PATTERN = (Scopes.AS_DI_FPMDIG, 5025, 'CHAN4')
     TS_EJESEPTG_PULSE = (Scopes.TS_PU_OSC_EJEBO, 5025, 'CHAN1')
     TS_EJESEPTF_PULSE = (Scopes.TS_PU_OSC_EJEBO, 5025, 'CHAN2')
     BO_EJEKCKR_PULSE = (Scopes.TS_PU_OSC_EJEBO, 5025, 'CHAN3')