Modified the Win32 datalink for MSTP to be more effecient by using semaphores for dataready signals. Also increased task priority. Still not fast enough - needs to respond to PFM and Token within 20ms to be compliant.

bacnet-stack/dlmstp.h

@@ -45,55 +45,6 @@
 #define MAX_HEADER (2+1+1+1+2+1+2+1)
 #define MAX_MPDU (MAX_HEADER+MAX_PDU)
 
-/*  The value 255 is used to denote broadcast when used as a */
-/* destination address but is not allowed as a value for a station. */
-/* Station addresses for master nodes can be 0-127.  */
-/* Station addresses for slave nodes can be 127-254.  */
-#define MSTP_BROADCAST_ADDRESS 255
-        
-/* MS/TP Frame Type */
-/* Frame Types 8 through 127 are reserved by ASHRAE. */
-#define FRAME_TYPE_TOKEN 0
-#define FRAME_TYPE_POLL_FOR_MASTER 1
-#define FRAME_TYPE_REPLY_TO_POLL_FOR_MASTER 2
-#define FRAME_TYPE_TEST_REQUEST 3
-#define FRAME_TYPE_TEST_RESPONSE 4
-#define FRAME_TYPE_BACNET_DATA_EXPECTING_REPLY 5
-#define FRAME_TYPE_BACNET_DATA_NOT_EXPECTING_REPLY 6
-#define FRAME_TYPE_REPLY_POSTPONED 7
-/* Frame Types 128 through 255: Proprietary Frames */
-/* These frames are available to vendors as proprietary (non-BACnet) frames. */
-/* The first two octets of the Data field shall specify the unique vendor */
-/* identification code, most significant octet first, for the type of */
-/* vendor-proprietary frame to be conveyed. The length of the data portion */
-/* of a Proprietary frame shall be in the range of 2 to 501 octets. */
-#define FRAME_TYPE_PROPRIETARY_MIN 128
-#define FRAME_TYPE_PROPRIETARY_MAX 255
-/* The initial CRC16 checksum value */
-#define CRC16_INITIAL_VALUE (0xFFFF)
-
-/* receive FSM states */
-typedef enum {
-    MSTP_RECEIVE_STATE_IDLE = 0,
-    MSTP_RECEIVE_STATE_PREAMBLE = 1,
-    MSTP_RECEIVE_STATE_HEADER = 2,
-    MSTP_RECEIVE_STATE_HEADER_CRC = 3,
-    MSTP_RECEIVE_STATE_DATA = 4
-} MSTP_RECEIVE_STATE;
-
-/* master node FSM states */
-typedef enum {
-    MSTP_MASTER_STATE_INITIALIZE = 0,
-    MSTP_MASTER_STATE_IDLE = 1,
-    MSTP_MASTER_STATE_USE_TOKEN = 2,
-    MSTP_MASTER_STATE_WAIT_FOR_REPLY = 3,
-    MSTP_MASTER_STATE_DONE_WITH_TOKEN = 4,
-    MSTP_MASTER_STATE_PASS_TOKEN = 5,
-    MSTP_MASTER_STATE_NO_TOKEN = 6,
-    MSTP_MASTER_STATE_POLL_FOR_MASTER = 7,
-    MSTP_MASTER_STATE_ANSWER_DATA_REQUEST = 8
-} MSTP_MASTER_STATE;
-
 typedef struct dlmstp_packet {
     bool ready;                 /* true if ready to be sent or received */
     BACNET_ADDRESS address;     /* source address */

bacnet-stack/mstp.c

@@ -105,10 +105,6 @@
 /* of a frame the node is transmitting: 20 bit times. */
 #define Tframe_gap 20
 
-/* The time without a DataAvailable or ReceiveError event before declaration */
-/* of loss of token: 500 milliseconds. */
-#define Tno_token 500
-
 /* The maximum time after the end of the stop bit of the final */
 /* octet of a transmitted frame before a node must disable its */
 /* EIA-485 driver: 15 bit times. */
@@ -121,12 +117,6 @@
    the reply may be in the transmit queue */
 #define Treply_delay 10
 
-/* The minimum time without a DataAvailable or ReceiveError event */
-/* that a node must wait for a station to begin replying to a */
-/* confirmed request: 255 milliseconds. (Implementations may use */
-/* larger values for this timeout, not to exceed 300 milliseconds.) */
-#define Treply_timeout 255
-
 /* Repeater turnoff delay. The duration of a continuous logical one state */
 /* at the active input port of an MS/TP repeater after which the repeater */
 /* will enter the IDLE state: 29 bit times < Troff < 40 bit times. */
@@ -141,12 +131,6 @@
 /* 15 milliseconds. */
 #define Tusage_delay 15
 
-/* The minimum time without a DataAvailable or ReceiveError event that a */
-/* node must wait for a remote node to begin using a token or replying to */
-/* a Poll For Master frame: 20 milliseconds. (Implementations may use */
-/* larger values for this timeout, not to exceed 100 milliseconds.) */
-#define Tusage_timeout 20
-
 /* we need to be able to increment without rolling over */
 #define INCREMENT_AND_LIMIT_UINT8(x) {if (x < 0xFF) x++;}
 

bacnet-stack/mstp.h

@@ -42,6 +42,72 @@
 #include "bacdef.h"
 #include "dlmstp.h"
 
+/*  The value 255 is used to denote broadcast when used as a */
+/* destination address but is not allowed as a value for a station. */
+/* Station addresses for master nodes can be 0-127.  */
+/* Station addresses for slave nodes can be 127-254.  */
+#define MSTP_BROADCAST_ADDRESS 255
+
+/* MS/TP Frame Type */
+/* Frame Types 8 through 127 are reserved by ASHRAE. */
+#define FRAME_TYPE_TOKEN 0
+#define FRAME_TYPE_POLL_FOR_MASTER 1
+#define FRAME_TYPE_REPLY_TO_POLL_FOR_MASTER 2
+#define FRAME_TYPE_TEST_REQUEST 3
+#define FRAME_TYPE_TEST_RESPONSE 4
+#define FRAME_TYPE_BACNET_DATA_EXPECTING_REPLY 5
+#define FRAME_TYPE_BACNET_DATA_NOT_EXPECTING_REPLY 6
+#define FRAME_TYPE_REPLY_POSTPONED 7
+/* Frame Types 128 through 255: Proprietary Frames */
+/* These frames are available to vendors as proprietary (non-BACnet) frames. */
+/* The first two octets of the Data field shall specify the unique vendor */
+/* identification code, most significant octet first, for the type of */
+/* vendor-proprietary frame to be conveyed. The length of the data portion */
+/* of a Proprietary frame shall be in the range of 2 to 501 octets. */
+#define FRAME_TYPE_PROPRIETARY_MIN 128
+#define FRAME_TYPE_PROPRIETARY_MAX 255
+/* The initial CRC16 checksum value */
+#define CRC16_INITIAL_VALUE (0xFFFF)
+
+/* receive FSM states */
+typedef enum {
+    MSTP_RECEIVE_STATE_IDLE = 0,
+    MSTP_RECEIVE_STATE_PREAMBLE = 1,
+    MSTP_RECEIVE_STATE_HEADER = 2,
+    MSTP_RECEIVE_STATE_HEADER_CRC = 3,
+    MSTP_RECEIVE_STATE_DATA = 4
+} MSTP_RECEIVE_STATE;
+
+/* master node FSM states */
+typedef enum {
+    MSTP_MASTER_STATE_INITIALIZE = 0,
+    MSTP_MASTER_STATE_IDLE = 1,
+    MSTP_MASTER_STATE_USE_TOKEN = 2,
+    MSTP_MASTER_STATE_WAIT_FOR_REPLY = 3,
+    MSTP_MASTER_STATE_DONE_WITH_TOKEN = 4,
+    MSTP_MASTER_STATE_PASS_TOKEN = 5,
+    MSTP_MASTER_STATE_NO_TOKEN = 6,
+    MSTP_MASTER_STATE_POLL_FOR_MASTER = 7,
+    MSTP_MASTER_STATE_ANSWER_DATA_REQUEST = 8
+} MSTP_MASTER_STATE;
+
+/* The time without a DataAvailable or ReceiveError event before declaration */
+/* of loss of token: 500 milliseconds. */
+#define Tno_token 500
+
+/* The minimum time without a DataAvailable or ReceiveError event */
+/* that a node must wait for a station to begin replying to a */
+/* confirmed request: 255 milliseconds. (Implementations may use */
+/* larger values for this timeout, not to exceed 300 milliseconds.) */
+#define Treply_timeout 255
+
+/* The minimum time without a DataAvailable or ReceiveError event that a */
+/* node must wait for a remote node to begin using a token or replying to */
+/* a Poll For Master frame: 20 milliseconds. (Implementations may use */
+/* larger values for this timeout, not to exceed 100 milliseconds.) */
+#define Tusage_timeout 20
+
+
 struct mstp_port_struct_t {
     MSTP_RECEIVE_STATE receive_state;
     /* When a master node is powered up or reset, */

bacnet-stack/ports/win32/dlmstp.c

@@ -25,10 +25,9 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <stddef.h>
+#include <stdlib.h>
 #include <string.h>
-#if PRINT_ENABLED
 #include <stdio.h>
-#endif
 #include "bacdef.h"
 #include "mstp.h"
 #include "dlmstp.h"
@@ -44,6 +43,9 @@ uint16_t MSTP_Packets = 0;
 
 /* packet queues */
 static DLMSTP_PACKET Receive_Packet;
+static HANDLE Receive_Packet_Flag;
+/* mechanism to wait for a frame in state machine */
+HANDLE Received_Frame_Flag;
 static DLMSTP_PACKET Transmit_Packet;
 /* local MS/TP port data - shared with RS-485 */
 volatile struct mstp_port_struct_t MSTP_Port;
@@ -69,6 +71,12 @@ void dlmstp_reinit(void)
 void dlmstp_cleanup(void)
 {
     /* nothing to do for static buffers */
+    if (Received_Frame_Flag) {
+        CloseHandle(Received_Frame_Flag);
+    }
+    if (Receive_Packet_Flag) {
+        CloseHandle(Receive_Packet_Flag);
+    }
 }
 
 /* returns number of bytes sent on success, zero on failure */
@@ -117,25 +125,29 @@ uint16_t dlmstp_receive(
     unsigned timeout) /* milliseconds to wait for a packet */
 {
     uint16_t pdu_len = 0;
+    DWORD wait_status = 0;
 
     /* see if there is a packet available, and a place
        to put the reply (if necessary) and process it */
-    if (Receive_Packet.ready) {
+    wait_status = WaitForSingleObject(Receive_Packet_Flag,timeout);
-        if (Receive_Packet.pdu_len) {
+    if (wait_status == WAIT_OBJECT_0) {
-            MSTP_Packets++;
+        if (Receive_Packet.ready) {
-            if (src) {
+            if (Receive_Packet.pdu_len) {
-                memmove(src,
+                MSTP_Packets++;
-                    &Receive_Packet.address,
+                if (src) {
-                    sizeof(Receive_Packet.address));
+                    memmove(src,
+                        &Receive_Packet.address,
+                        sizeof(Receive_Packet.address));
+                }
+                if (pdu) {
+                    memmove(pdu,
+                        &Receive_Packet.pdu,
+                        sizeof(Receive_Packet.pdu));
+                }
+                pdu_len = Receive_Packet.pdu_len;
             }
-            if (pdu) {
+            Receive_Packet.ready = false;
-                memmove(pdu,
-                    &Receive_Packet.pdu,
-                    sizeof(Receive_Packet.pdu));
-            }
-            pdu_len = Receive_Packet.pdu_len;
         }
-        Receive_Packet.ready = false;
     }
 
     return pdu_len;
@@ -145,7 +157,7 @@ static void dlmstp_receive_fsm_task(void *pArg)
 {
     bool received_frame;
 
-    //(void)SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
+    (void)SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
     while (TRUE) {
         /* only do receive state machine while we don't have a frame */
         if ((MSTP_Port.ReceivedValidFrame == false) &&
@@ -155,8 +167,10 @@ static void dlmstp_receive_fsm_task(void *pArg)
                 MSTP_Receive_Frame_FSM(&MSTP_Port);
                 received_frame = MSTP_Port.ReceivedValidFrame ||
                     MSTP_Port.ReceivedInvalidFrame;
-                if (received_frame)
+                if (received_frame) {
+                    ReleaseSemaphore(Received_Frame_Flag, 1, NULL);
                     break;
+                }
             } while (MSTP_Port.DataAvailable);
         }
     }
@@ -164,14 +178,27 @@ static void dlmstp_receive_fsm_task(void *pArg)
 
 static void dlmstp_master_fsm_task(void *pArg)
 {
-    //(void)SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
+    DWORD dwMilliseconds = 0;
+
+    (void)SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
     while (TRUE) {
-        /* only do master state machine while rx is idle */
+        switch (MSTP_Port.master_state) {
-        if (MSTP_Port.receive_state == MSTP_RECEIVE_STATE_IDLE) {
+            case MSTP_MASTER_STATE_IDLE:
-            while (MSTP_Master_Node_FSM(&MSTP_Port)) {
+                dwMilliseconds = Tno_token;
-                Sleep(0);
+                break;
-            };
+            case MSTP_MASTER_STATE_WAIT_FOR_REPLY:
+                dwMilliseconds = Treply_timeout;
+                break;
+            case MSTP_MASTER_STATE_POLL_FOR_MASTER:
+                dwMilliseconds = Tusage_timeout;
+                break;
+            default:
+                dwMilliseconds = 0;
+                break;
         }
+        if (dwMilliseconds)
+            WaitForSingleObject(Received_Frame_Flag,dwMilliseconds);
+        MSTP_Master_Node_FSM(&MSTP_Port);
     }
 }
 
@@ -212,6 +239,7 @@ uint16_t MSTP_Put_Receive(
         volatile struct mstp_port_struct_t *mstp_port)
 {
     uint16_t pdu_len = 0;
+    BOOL rc;
 
     if (!Receive_Packet.ready) {
         /* bounds check - maybe this should send an abort? */
@@ -225,6 +253,7 @@ uint16_t MSTP_Put_Receive(
             mstp_port->SourceAddress);
         Receive_Packet.pdu_len = mstp_port->DataLength;
         Receive_Packet.ready = true;
+        rc = ReleaseSemaphore(Receive_Packet_Flag, 1, NULL);
     }
 
     return pdu_len;
@@ -380,6 +409,14 @@ bool dlmstp_init(char *ifname)
     /* initialize packet queue */
     Receive_Packet.ready = false;
     Receive_Packet.pdu_len = 0;
+    Receive_Packet_Flag = CreateSemaphore (NULL,0,1,"dlmstpReceivePacket");
+    if (Receive_Packet_Flag == NULL)
+        exit(1);
+    Received_Frame_Flag = CreateSemaphore (NULL,0,1,"dlsmtpReceiveFrame");
+    if (Received_Frame_Flag == NULL) {
+        CloseHandle(Receive_Packet_Flag);
+        exit(1);
+    }
     /* initialize hardware */
     /* initialize hardware */
     if (ifname) {
@@ -494,7 +531,7 @@ int main(int argc, char *argv[])
     dlmstp_init(Network_Interface);
     /* forever task */
     for (;;) {
-        pdu_len = dlmstp_receive(NULL,NULL,0,0);
+        pdu_len = dlmstp_receive(NULL,NULL,0,INFINITE);
 #if 0
         MSTP_Create_And_Send_Frame(
             &MSTP_Port,
@@ -503,7 +540,6 @@ int main(int argc, char *argv[])
             MSTP_Port.This_Station,
             NULL, 0);
 #endif
-        Sleep(10);
     }
 
     return 0;

bacnet-stack/ports/win32/rs485.c

@@ -325,8 +325,7 @@ void RS485_Check_UART_Data(struct mstp_port_struct_t *mstp_port)
             }
         } else {
             if (dwRead) {
-                mstp_port->DataRegister = lpBuf[0];    /* FIXME: Get this data from UART or buffer */
+                mstp_port->DataRegister = lpBuf[0];
-                /* if data is ready, */
                 mstp_port->DataAvailable = TRUE;
             }
         }