Index: MessagePayloads.h
===================================================================
diff -u -rf677679e0381ee76e2370d4cd09cf13f9172a5c8 -ref31ae5f4eb4f62b8c1b5cdc467507d8d0787640
--- MessagePayloads.h	(.../MessagePayloads.h)	(revision f677679e0381ee76e2370d4cd09cf13f9172a5c8)
+++ MessagePayloads.h	(.../MessagePayloads.h)	(revision ef31ae5f4eb4f62b8c1b5cdc467507d8d0787640)
@@ -46,6 +46,7 @@
     F32  bicarbConvFactor;                              ///< Conversion factor of bicarbonate.
     U32  sodium;                                        ///< Set sodium being used to make dialysate.
     U32  bicarbonate;                                   ///< Set bicarbonate being used to make dialysate.
+    F32  substitutionRate;                              ///< Set substitution (D92) pump rate (mL/min).
 } DIALYSATE_DELIVERY_REQ_PAYLOAD_T;
 
 /// Payload record structure for requesting pre generate dialysate.