diff --git a/bacnet-stack/bacdcode.c b/bacnet-stack/bacdcode.c
index 00b8a5cd..a20755cf 100644
--- a/bacnet-stack/bacdcode.c
+++ b/bacnet-stack/bacdcode.c
@@ -1038,6 +1038,27 @@ int encode_tagged_octet_string(uint8_t * apdu,
     return apdu_len;
 }
 
+/* from clause 20.2.8 Encoding of an Octet String Value */
+/* and 20.2.1 General Rules for Encoding BACnet Tags */
+/* returns the number of apdu bytes consumed */
+int encode_context_octet_string(uint8_t * apdu,
+    int tag_number,
+    BACNET_OCTET_STRING * octet_string)
+{
+    int apdu_len = 0;
+
+    if (apdu && octet_string) {
+        apdu_len = encode_tag(&apdu[0], (uint8_t) tag_number, 
+            true, octetstring_length(octet_string));
+        if ((apdu_len + octetstring_length(octet_string)) < MAX_APDU)
+            apdu_len += encode_octet_string(&apdu[apdu_len], octet_string);
+        else
+            apdu_len = 0;
+    }
+
+    return apdu_len;
+}
+
 /* from clause 20.2.8 Encoding of an Octet String Value */
 /* and 20.2.1 General Rules for Encoding BACnet Tags */
 /* returns the number of apdu bytes consumed */
diff --git a/bacnet-stack/bacdcode.h b/bacnet-stack/bacdcode.h
index 4799dd6c..b1b9f21a 100644
--- a/bacnet-stack/bacdcode.h
+++ b/bacnet-stack/bacdcode.h
@@ -108,6 +108,9 @@ extern "C" {
         BACNET_OCTET_STRING * octet_string);
     int encode_tagged_octet_string(uint8_t * apdu,
         BACNET_OCTET_STRING * octet_string);
+    int encode_context_octet_string(uint8_t * apdu,
+        int tag_number,
+        BACNET_OCTET_STRING * octet_string);
     int decode_octet_string(uint8_t * apdu, uint32_t len_value,
         BACNET_OCTET_STRING * octet_string);
 
diff --git a/bacnet-stack/demo/object/bacfile.c b/bacnet-stack/demo/object/bacfile.c
index 624fdd45..583bc41a 100644
--- a/bacnet-stack/demo/object/bacfile.c
+++ b/bacnet-stack/demo/object/bacfile.c
@@ -227,6 +227,7 @@ bool bacfile_write_property(BACNET_WRITE_PROPERTY_DATA * wp_data,
         *error_code = ERROR_CODE_UNKNOWN_OBJECT;
         return false;
     }
+    
     /* decode the some of the request */
     switch (wp_data->object_property) {
     case PROP_ARCHIVE:
diff --git a/bacnet-stack/wp.c b/bacnet-stack/wp.c
index 235e5287..74ff6f03 100644
--- a/bacnet-stack/wp.c
+++ b/bacnet-stack/wp.c
@@ -67,8 +67,8 @@ int wp_encode_apdu(uint8_t * apdu,
         /* propertyValue */
         len = encode_opening_tag(&apdu[apdu_len], 3);
         apdu_len += len;
-        memmove(&apdu[apdu_len], &data->value[0], value_len);
-        apdu_len += value_len;
+        len = bacapp_encode_application_data(&apdu[apdu_len], &data->value);
+        apdu_len += len;
         len = encode_closing_tag(&apdu[apdu_len], 3);
         apdu_len += len;
         /* optional priority - 0 if not set, 1..16 if set */
@@ -82,24 +82,11 @@ int wp_encode_apdu(uint8_t * apdu,
     return apdu_len;
 }
 
-int wp_encode_application_apdu(uint8_t * apdu,
-     uint8_t invoke_id,
-     BACNET_WRITE_PROPERTY_DATA * data,
-     BACNET_APPLICATION_DATA_VALUE * value)
-{
-     data->value_len = bacapp_encode_application_data(
-       &data->value[0], value);
-
-     return  wp_encode_apdu(apdu, invoke_id, data);
-}
-
-
 /* decode the service request only */
 /* FIXME: there could be various error messages returned
    using unique values less than zero */
 int wp_decode_service_request(uint8_t * apdu,
-    unsigned apdu_len, BACNET_WRITE_PROPERTY_DATA * data,
-    BACNET_APPLICATION_DATA_VALUE * value)
+    unsigned apdu_len, BACNET_WRITE_PROPERTY_DATA * data)
 {
     int len = 0;
     int tag_len = 0;
@@ -143,11 +130,11 @@ int wp_decode_service_request(uint8_t * apdu,
         if (decode_is_context_specific(&apdu[len]))
             return -2;
         len += bacapp_decode_application_data(&apdu[len],
-            apdu_len - len, &value);
+            apdu_len - len, &data->value);
         /* FIXME: check the return value; abort if no valid data? */
         /* FIXME: there might be more than one data element in here! */
         if (!decode_is_closing_tag_number(&apdu[len], 3))
-            return -1;
+            return -4;
         /* a tag number of 3 is not extended so only one octet */
         len++;
         /* Tag 4: optional Priority - assumed MAX if not explicitly set */
@@ -164,7 +151,7 @@ int wp_decode_service_request(uint8_t * apdu,
                     && (unsigned_value <= BACNET_MAX_PRIORITY)) {
                     data->priority = (uint8_t) unsigned_value;
                 } else
-                    return -1;
+                    return -5;
             }
         }
     }
diff --git a/bacnet-stack/wp.h b/bacnet-stack/wp.h
index d0546070..99098ef7 100644
--- a/bacnet-stack/wp.h
+++ b/bacnet-stack/wp.h
@@ -47,8 +47,7 @@ typedef struct BACnet_Write_Property_Data {
     uint32_t object_instance;
     BACNET_PROPERTY_ID object_property;
     int32_t array_index;        /* use BACNET_ARRAY_ALL when not setting */
-    uint8_t value[MAX_APDU];
-    uint16_t value_len;
+    BACNET_APPLICATION_DATA_VALUE value;
     uint8_t priority;           /* use BACNET_NO_PRIORITY if no priority */
 } BACNET_WRITE_PROPERTY_DATA;
 
@@ -60,23 +59,16 @@ extern "C" {
     int wp_encode_apdu(uint8_t * apdu,
         uint8_t invoke_id, BACNET_WRITE_PROPERTY_DATA * data);
 
-    int wp_encode_application_apdu(uint8_t * apdu,
-        uint8_t invoke_id,
-        BACNET_WRITE_PROPERTY_DATA * data,
-        BACNET_APPLICATION_DATA_VALUE * value);
-
 /* decode the service request only */
     int wp_decode_service_request(uint8_t * apdu,
         unsigned apdu_len, BACNET_WRITE_PROPERTY_DATA * data);
 
+#ifdef TEST
+#include "ctest.h"
     int wp_decode_apdu(uint8_t * apdu,
         unsigned apdu_len,
         uint8_t * invoke_id, BACNET_WRITE_PROPERTY_DATA * data);
 
-
-#ifdef TEST
-#include "ctest.h"
-
     void test_ReadProperty(Test * pTest);
     void test_ReadPropertyAck(Test * pTest);
 #endif