diff --git a/site_ansto/hardsup/nhq200util.c b/site_ansto/hardsup/nhq200util.c
index 1a72a028..5ace3227 100644
--- a/site_ansto/hardsup/nhq200util.c
+++ b/site_ansto/hardsup/nhq200util.c
@@ -382,6 +382,7 @@ int NHQ200_Check_Status(pNHQ200 self)
   /* Can be called to check for correct operation of the NHQ200 */
 {
   int iRet, iRetry, busy, notbusy;
+  int iRspLen;
   char pCommand[20];
   char pReply[132];
   /* Check the busy status.
@@ -395,8 +396,9 @@ int NHQ200_Check_Status(pNHQ200 self)
   printf("Checking status...");
   do
   {
+    iRspLen = 79;
     sprintf(pCommand,"S%d", self->iControl);
-    iRet=AsyncUnitTransact(self->unit, pCommand, strlen(pCommand), pReply, 79);
+    iRet=AsyncUnitTransact(self->unit, pCommand, strlen(pCommand), pReply, &iRspLen);
     if (iRet <= 0)
     {
       printf("Comms error!\n");
@@ -497,6 +499,7 @@ int NHQ200_Config(pNHQ200 *pData, int iTmo, int iRead, int iControl,
 int NHQ200_Send(pNHQ200 *pData, char *pCommand, char *pReply, int iLen)
 {
   int iRet;
+  int iRspLen;
   int commandlen;
   pNHQ200 self;
 
@@ -505,7 +508,8 @@ int NHQ200_Send(pNHQ200 *pData, char *pCommand, char *pReply, int iLen)
   /* Send command direct to the NHQ200 */
   commandlen=strlen(pCommand);
 
-  iRet=AsyncUnitTransact(self->unit, pCommand, commandlen, pReply, iLen);
+  iRspLen = iLen;
+  iRet=AsyncUnitTransact(self->unit, pCommand, commandlen, pReply, &iRspLen);
 
   return iRet;
 }
@@ -550,6 +554,7 @@ int NHQ200_Set(pNHQ200 *pData, float fVal)
 {
   char pCommand[20], pCommandRead[20], pReply[132], pCommandGo[20];
   int iRet;
+  int iRspLen;
   const float fPrecision = 0.1;
   float fDelta, fRead;
   pNHQ200 self;
@@ -567,11 +572,13 @@ int NHQ200_Set(pNHQ200 *pData, float fVal)
   sprintf(pCommandRead,"D%d", self->iControl);
 
   /* send Dn=nnn command, we get a blank line response */
-  iRet = AsyncUnitTransact(self->unit,pCommand,strlen(pCommand),pReply,131);
+  iRspLen = 131;
+  iRet = AsyncUnitTransact(self->unit,pCommand,strlen(pCommand),pReply, &iRspLen);
   if (iRet <= 0)
     return iRet;
   /* read the set value again using the Dn command */
-  iRet = AsyncUnitTransact(self->unit,pCommandRead,strlen(pCommandRead),pReply,131);
+  iRspLen = 131;
+  iRet = AsyncUnitTransact(self->unit,pCommandRead,strlen(pCommandRead),pReply, &iRspLen);
   if (iRet <= 0)
     return iRet;
   printf("D%d:  Response %d chars: '%s'\n",self->iControl, iRet, pReply);
@@ -588,7 +595,8 @@ int NHQ200_Set(pNHQ200 *pData, float fVal)
   if(fDelta < fPrecision)
   {
     sprintf(pCommandGo, "G%d", self->iControl);
-    iRet = AsyncUnitTransact(self->unit,pCommandGo,strlen(pCommandGo),pReply,131);
+    iRspLen = 131;
+    iRet = AsyncUnitTransact(self->unit,pCommandGo,strlen(pCommandGo),pReply, &iRspLen);
     if (iRet <= 0)
       return iRet;
     printf("G%d:  Response %d chars: '%s'\n",self->iControl, iRet, pReply);