1. Added new file s_wpm.c (Send_Write_Property_Multiple_Request_Data)

2. Changed file wpm.h (new struct added BACNET_WRITE_ACCESS_DATA, declaration for wpm_encode_apdu added)
3. Changed file wpm.c (definition added for wpm_encode_apdu)
4. client.h file updated with declaration for Send_Write_Property_Multiple_Request_Data

Thank you for the contribution, Daniel Blazevic!

bacnet-stack/include/client.h

@@ -34,6 +34,7 @@
 #include "bacapp.h"
 #include "bacenum.h"
 #include "rpm.h"
+#include "wpm.h"
 #include "cov.h"
 #include "event.h"
 #include "lso.h"
@@ -151,6 +152,9 @@ extern "C" {
         int application_data_len,
         uint8_t priority,
         uint32_t array_index);
+	uint8_t Send_Write_Property_Multiple_Request_Data(
+		uint32_t device_id,
+		BACNET_WRITE_ACCESS_DATA * write_access_data);
 
 /* returns the invoke ID for confirmed request, or 0 if failed */
     uint8_t Send_Reinitialize_Device_Request(

bacnet-stack/include/wpm.h

@@ -35,6 +35,14 @@
 extern "C" {
 #endif /* __cplusplus */
 
+	struct BACnet_Write_Access_Data;
+	typedef struct BACnet_Write_Access_Data {
+		BACNET_OBJECT_TYPE object_type;
+		uint32_t object_instance;
+		/* simple linked list of values */
+		BACNET_PROPERTY_VALUE *listOfProperties;
+		struct BACnet_Write_Access_Data *next;
+	} BACNET_WRITE_ACCESS_DATA;
 
     /* decode the service request only */
     int wpm_decode_object_id(
@@ -61,6 +69,11 @@ extern "C" {
     int wpm_encode_apdu_object_property(
         uint8_t * apdu,
         BACNET_WRITE_PROPERTY_DATA * wpdata);
+	int wpm_encode_apdu(
+		uint8_t * apdu,
+		size_t max_apdu,
+		uint8_t invoke_id,
+		BACNET_WRITE_ACCESS_DATA * write_access_data);
 
     /* encode service */
     int wpm_ack_encode_apdu_init(