Index: firmware/App/Services/FpgaDD.c
===================================================================
diff -u -rc408c29123e153d5a004b5b58bd455d01824f7f1 -r78842b478a83315eda5d877a99b16f3b899b7727
--- firmware/App/Services/FpgaDD.c	(.../FpgaDD.c)	(revision c408c29123e153d5a004b5b58bd455d01824f7f1)
+++ firmware/App/Services/FpgaDD.c	(.../FpgaDD.c)	(revision 78842b478a83315eda5d877a99b16f3b899b7727)
@@ -92,6 +92,8 @@
 
 #define FPGA_FLOATER_LEVEL_BIT          0x03                    ///< Floater level bit mask.
 
+#define FPGA_PRIMARY_HEATER_CNTRL_BIT   0x01                    ///< FPGA GIO Primary heater control bit mask
+
 /// FPGA size of V3 read bytes.
 #define FPGA_SIZE_OF_V3_READ_BYTES      ( FPGA_READ_V3_END_BYTE_NUM - FPGA_READ_V3_START_BYTE_NUM )
 
@@ -321,7 +323,9 @@
     U16 fpgaVUFPWMPeriod;                   ///< Reg 138. VUF PWM period
     U16 fpgaVUFPWMPullin;                   ///< Reg 140. VUF PWM pull in
     U16 fpgaCPARevCount;                    ///< Reg 142. Acid Concentrate pump revolution count
-    U16 fpgaCPBRevCount;                    ///< Reg 144. Bicard Concentrate pump revolution count
+    U16 fpgaCPBRevCount;                    ///< Reg 144. Bicarb Concentrate pump revolution count
+    U08 fpgaADCControl;                     ///< Reg 146. FPGA internal ADC Control register for debugging
+    U08 fpgaGPIOControl;                    ///< Reg 147. FPGA GPIO control interface
 } FPGA_ACTUATORS_T;
 #pragma pack(pop)
 
@@ -1317,6 +1321,27 @@
 
 /*********************************************************************//**
  * @brief
+ * The setFPGACPrimaryHeaterOnOffControl function sets the primary heater
+ * On/Off control.
+ * @details \b Inputs: none
+ * @details \b Outputs: fpgaGPIOControl
+ * @param flag Turn heater ON when true, otherwise not.
+ * @return none
+ *************************************************************************/
+void setFPGACPrimaryHeaterOnOffControl( BOOL flag )
+{
+    if ( TRUE == flag)
+    {
+        fpgaActuatorSetPoints.fpgaGPIOControl |= FPGA_PRIMARY_HEATER_CNTRL_BIT;
+    }
+    else
+    {
+        fpgaActuatorSetPoints.fpgaGPIOControl &= ~FPGA_PRIMARY_HEATER_CNTRL_BIT;
+    }
+}
+
+/*********************************************************************//**
+ * @brief
  * The getFPGAVersions function gets the FPGA version numbers.
  * @details \b Inputs: fpgaHeader
  * @details \b Outputs: none