Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -r26a1ca768a98655b83457493b4e2eeed104efeb5 -r2a437c0b6461a17c6474d7d3c7964463abc4651b
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 26a1ca768a98655b83457493b4e2eeed104efeb5)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 2a437c0b6461a17c6474d7d3c7964463abc4651b)
@@ -637,6 +637,8 @@
     MESSAGE_T msg;
     DG_ACID_CONCENTRATES_RECORD_T acid;
     DG_BICARB_CONCENTRATES_RECORD_T bicarb;
+    F32 acidConcMixRatio   = 0.0F;
+    F32 bicarbConcMixRatio = 0.0F;
     // By the time these are requested, the prepare time is no longer needed since the concentrate lines are
     // primed before the actual treatment starts
     U32 fillPrepTimeMS = 0;
@@ -645,15 +647,18 @@
     getAcidConcentrateCalRecord( &acid );
     getBicarbConcentrateCalRecord( &bicarb );
 
+    acidConcMixRatio   = acid.acidConcentrate[ CAL_DATA_ACID_CONCENTRATE_1 ].acidConcMixRatio;
+    bicarbConcMixRatio = bicarb.bicarbConcentrate[ CAL_DATA_BICARB_CONCENTRATE_1 ].bicarbConcMixRatio;
+
     // Create a message record
     blankMessage( &msg );
     msg.hdr.msgID = MSG_ID_DG_CONCENTRATE_MIXING_RATIOS_DATA;
     msg.hdr.payloadLen = sizeof( F32 ) + sizeof( F32 ) + sizeof( U32 );
 
     // Fill message payload
-    memcpy( payloadPtr, &acid.acidConcentrate[ CAL_DATA_ACID_CONCENTRATE_1 ].acidConcMixRatio, sizeof( F32 ) );
+    memcpy( payloadPtr, &acidConcMixRatio, sizeof( F32 ) );
     payloadPtr += sizeof( F32 );
-    memcpy( payloadPtr, &bicarb.bicarbConcentrate[ CAL_DATA_BICARB_CONCENTRATE_1 ].bicarbConcMixRatio, sizeof( F32 ) );
+    memcpy( payloadPtr, &bicarbConcMixRatio, sizeof( F32 ) );
     payloadPtr += sizeof( U32 );
     memcpy( payloadPtr, &fillPrepTimeMS, sizeof( U32 ) );