From c61cb222704641579a44dbca4b32d6484ec31527 Mon Sep 17 00:00:00 2001
From: Douglas Clowes <dcl@ansto.gov.au>
Date: Fri, 12 Dec 2014 14:25:24 +1100
Subject: [PATCH] Handle bigger modbus messages

---
 site_ansto/hardsup/modbus_asyncprotocol.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/site_ansto/hardsup/modbus_asyncprotocol.c b/site_ansto/hardsup/modbus_asyncprotocol.c
index cde567e9..3779447b 100644
--- a/site_ansto/hardsup/modbus_asyncprotocol.c
+++ b/site_ansto/hardsup/modbus_asyncprotocol.c
@@ -20,7 +20,7 @@
  */
 #define PROTOCOL_NAME "MODBUS_AP"
 #define PROTOCOL_INIT MODBUSInitProtocol
-#define ADUSIZE 17
+#define ADUSIZE 300
 
 /*
  * MODBUS DataTypes
@@ -63,7 +63,7 @@ struct modbus_private_t {
   int aduLen;
   int RespLen;
   int DatLen;
-  unsigned char ADU[ADUSIZE]; /* Allows upto 8 bytes if data */
+  unsigned char ADU[ADUSIZE]; /* Allows up to 255 bytes of data */
   pDynString rdBuffer;
 };
 
@@ -89,6 +89,10 @@ static ProtoPrivate *makeProtoPrivate()
 static ProtoPrivate *Proto_KillPrivate(ProtoPrivate *priv)
 {
   if (priv) {
+    if (priv->wrBuffer) {
+      DeleteDynString(priv->wrBuffer);
+      priv->wrBuffer = NULL;
+    }
     if (priv->rxBuffer) {
       DeleteDynString(priv->rxBuffer);
       priv->rxBuffer = NULL;
@@ -268,7 +272,7 @@ static int ModbusOutput(pPrivate myPriv, pDynString wrBuffer, pDynString send_bu
   int ADUlen, PDUlenPlusUID;
   unsigned int i, j;
   char *cmdLine;
-  unsigned char ADU[32], ieee[4];
+  unsigned char ADU[ADUSIZE], ieee[4];
 
   cmdLine = GetCharArray(wrBuffer);
   for (i=0; i < 4; i++)