Merge branch 'master' into feature/opcua

coupler/opc-ua-server/opc-ua-server.py

-"""
-Simple OPC UA server with one paremeter (temp).
-"""
-from opcua import Server
-from random import randint
-import time
-
-server = Server()
-url = "opc.tcp://0.0.0.0:4840"
-server.set_endpoint(url)
-
-name = "OPCUA_SIMULATION_SERVER"
-addspace = server.register_namespace(name)
-node = server.get_objects_node()
-
-Param = node.add_object(addspace, "Parameters")
-Temp = Param.add_variable(addspace, "Temperature", 0)
-Temp.set_writable()
-
-server.start()
-
-print ("started at %s" %url)
-
-while 1:
-    Temp.set_value(randint(10,50))
-    time.sleep(10)

coupler/opc-ua-server/server.c

@@ -16,18 +16,26 @@
 #include "open62541.h"
 
 // global relay state
-uint8_t myrelay = 0;
+uint8_t I2C_0_RELAYS_STATE = 0; // state of 4 relays at I2C slave 0
+uint8_t I2C_1_RELAYS_STATE = 0; // state of 4 relays at I2C slave 1
 
-static int setRelayState(int command) {
+// the default addresses of MOD-IOs
+const int I2C_0_ADDR = 0x58;
+const int I2C_1_ADDR = 0x59;
+
+// the block device at host machine
+static const char I2C_BLOCK_DEVICE_NAME[] = "/dev/i2c-1";
+
+
+static int setRelayState(int command, int i2c_addr) {
     /*
      *  Set relays' state over I2C
      */
     int file;
-    int adapter_nr = 1; /* probably dynamically determined */
     char filename[20];
 
     // step 1: open device
-    snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
+    snprintf(filename, 19, I2C_BLOCK_DEVICE_NAME);
     file = open(filename, O_RDWR);
     if (file < 0) {
         /* ERROR HANDLING; you can check errno to see what went wrong */
@@ -36,8 +44,7 @@ static int setRelayState(int command) {
     }
 
     // step 2: address the slave by its address 
-    int addr = 0x58; /* The I2C address */
-    if (ioctl(file, I2C_SLAVE, addr) < 0) {
+    if (ioctl(file, I2C_SLAVE, i2c_addr) < 0) {
         /* ERROR HANDLING; you can check errno to see what went wrong */
         printf("Error addressing i2c slave.");
         exit(1);
@@ -65,61 +72,109 @@ static void addVariable(UA_Server *server) {
     UA_NodeId parentNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER);
     UA_NodeId parentReferenceNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES);
     
-    // relay 0
+    // I2C0 / relay 0
     UA_VariableAttributes attr0 = UA_VariableAttributes_default;
     UA_Variant_setScalar(&attr0.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
-    attr0.description = UA_LOCALIZEDTEXT("en-US","Relay 0");
-    attr0.displayName = UA_LOCALIZEDTEXT("en-US", "Relay 0");
+    attr0.description = UA_LOCALIZEDTEXT("en-US","I2C0 / Relay 0");
+    attr0.displayName = UA_LOCALIZEDTEXT("en-US", "I2C0 / Relay 0");
     attr0.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
     attr0.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
-
-    UA_NodeId myIntegerNodeId0 = UA_NODEID_STRING(1, "relay0");
-    UA_QualifiedName myIntegerName0 = UA_QUALIFIEDNAME(1, "Relay 0");
+    UA_NodeId myIntegerNodeId0 = UA_NODEID_STRING(1, "i2c0.relay0");
+    UA_QualifiedName myIntegerName0 = UA_QUALIFIEDNAME(1, "I2C0 / Relay 0");
     UA_Server_addVariableNode(server, myIntegerNodeId0, parentNodeId,
                               parentReferenceNodeId, myIntegerName0,
                               UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr0, NULL, NULL);
-    // relay 1
+    // I2C0 / relay 1
     UA_VariableAttributes attr1 = UA_VariableAttributes_default;
     UA_Variant_setScalar(&attr1.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
-    attr1.description = UA_LOCALIZEDTEXT("en-US","Relay 1");
-    attr1.displayName = UA_LOCALIZEDTEXT("en-US", "Relay 1");
+    attr1.description = UA_LOCALIZEDTEXT("en-US","I2C0 / Relay 1");
+    attr1.displayName = UA_LOCALIZEDTEXT("en-US", "I2C0 / Relay 1");
     attr1.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
     attr1.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
-
-    UA_NodeId myIntegerNodeId1 = UA_NODEID_STRING(1, "relay1");
-    UA_QualifiedName myIntegerName1 = UA_QUALIFIEDNAME(1, "Relay 1");
+    UA_NodeId myIntegerNodeId1 = UA_NODEID_STRING(1, "i2c0.relay1");
+    UA_QualifiedName myIntegerName1 = UA_QUALIFIEDNAME(1, "I2C0 / Relay 1");
     UA_Server_addVariableNode(server, myIntegerNodeId1, parentNodeId,
                               parentReferenceNodeId, myIntegerName1,
                               UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr1, NULL, NULL);
 
-    // relay 2
+    // I2C0 / relay 2
     UA_VariableAttributes attr2 = UA_VariableAttributes_default;
     UA_Variant_setScalar(&attr2.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
-    attr2.description = UA_LOCALIZEDTEXT("en-US","Relay 2");
-    attr2.displayName = UA_LOCALIZEDTEXT("en-US", "Relay 2");
+    attr2.description = UA_LOCALIZEDTEXT("en-US","I2C0 / Relay 2");
+    attr2.displayName = UA_LOCALIZEDTEXT("en-US", "I2C0 / Relay 2");
     attr2.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
     attr2.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
-
-    UA_NodeId myIntegerNodeId2 = UA_NODEID_STRING(1, "relay2");
-    UA_QualifiedName myIntegerName2 = UA_QUALIFIEDNAME(1, "Relay 2");
+    UA_NodeId myIntegerNodeId2 = UA_NODEID_STRING(1, "i2c0.relay2");
+    UA_QualifiedName myIntegerName2 = UA_QUALIFIEDNAME(1, "I2C0 / Relay 2");
     UA_Server_addVariableNode(server, myIntegerNodeId2, parentNodeId,
                               parentReferenceNodeId, myIntegerName2,
                               UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr2, NULL, NULL);
 
-    // relay 3
+    // I2C0 / relay 3
     UA_VariableAttributes attr3 = UA_VariableAttributes_default;
     UA_Variant_setScalar(&attr3.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
-    attr3.description = UA_LOCALIZEDTEXT("en-US","Relay 3");
-    attr3.displayName = UA_LOCALIZEDTEXT("en-US", "Relay 3");
+    attr3.description = UA_LOCALIZEDTEXT("en-US","I2C0 / Relay 3");
+    attr3.displayName = UA_LOCALIZEDTEXT("en-US", "I2C0 / Relay 3");
     attr3.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
     attr3.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
-
-    UA_NodeId myIntegerNodeId3 = UA_NODEID_STRING(1, "relay3");
-    UA_QualifiedName myIntegerName3 = UA_QUALIFIEDNAME(1, "Relay 3");
+    UA_NodeId myIntegerNodeId3 = UA_NODEID_STRING(1, "i2c0.relay3");
+    UA_QualifiedName myIntegerName3 = UA_QUALIFIEDNAME(1, "I2C0 / Relay 3");
     UA_Server_addVariableNode(server, myIntegerNodeId3, parentNodeId,
                               parentReferenceNodeId, myIntegerName3,
                               UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr3, NULL, NULL);
 
+    // I2C1 / relay 0
+    UA_VariableAttributes attr4 = UA_VariableAttributes_default;
+    UA_Variant_setScalar(&attr4.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
+    attr4.description = UA_LOCALIZEDTEXT("en-US","I2C1 / Relay 0");
+    attr4.displayName = UA_LOCALIZEDTEXT("en-US", "I2C1 / Relay 0");
+    attr4.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
+    attr4.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
+    UA_NodeId myIntegerNodeId4 = UA_NODEID_STRING(1, "i2c1.relay0");
+    UA_QualifiedName myIntegerName4 = UA_QUALIFIEDNAME(1, "I2C1 / Relay 0");
+    UA_Server_addVariableNode(server, myIntegerNodeId4, parentNodeId,
+                              parentReferenceNodeId, myIntegerName4,
+                              UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr4, NULL, NULL);
+ 
+    // I2C1 / relay 1 
+    UA_VariableAttributes attr5 = UA_VariableAttributes_default;
+    UA_Variant_setScalar(&attr5.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
+    attr5.description = UA_LOCALIZEDTEXT("en-US","I2C1 / Relay 1");
+    attr5.displayName = UA_LOCALIZEDTEXT("en-US", "I2C1 / Relay 1");
+    attr5.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
+    attr5.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
+    UA_NodeId myIntegerNodeId5 = UA_NODEID_STRING(1, "i2c1.relay1");
+    UA_QualifiedName myIntegerName5 = UA_QUALIFIEDNAME(1, "I2C1 / Relay 1");
+    UA_Server_addVariableNode(server, myIntegerNodeId5, parentNodeId,
+                              parentReferenceNodeId, myIntegerName5,
+                              UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr5, NULL, NULL);
+    
+    // I2C1 / relay 2 
+    UA_VariableAttributes attr6 = UA_VariableAttributes_default;
+    UA_Variant_setScalar(&attr6.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
+    attr6.description = UA_LOCALIZEDTEXT("en-US","I2C1 / Relay 2");
+    attr6.displayName = UA_LOCALIZEDTEXT("en-US", "I2C1 / Relay 2");
+    attr6.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
+    attr6.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
+    UA_NodeId myIntegerNodeId6 = UA_NODEID_STRING(1, "i2c1.relay2");
+    UA_QualifiedName myIntegerName6 = UA_QUALIFIEDNAME(1, "I2C1 / Relay 2");
+    UA_Server_addVariableNode(server, myIntegerNodeId6, parentNodeId,
+                              parentReferenceNodeId, myIntegerName6,
+                              UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr6, NULL, NULL);
+    
+    // I2C1 / relay 3 
+    UA_VariableAttributes attr7 = UA_VariableAttributes_default;
+    UA_Variant_setScalar(&attr7.value, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
+    attr7.description = UA_LOCALIZEDTEXT("en-US","I2C1 / Relay 3");
+    attr7.displayName = UA_LOCALIZEDTEXT("en-US", "I2C1 / Relay 3");
+    attr7.dataType = UA_TYPES[UA_TYPES_INT32].typeId;
+    attr7.accessLevel = UA_ACCESSLEVELMASK_READ | UA_ACCESSLEVELMASK_WRITE;
+    UA_NodeId myIntegerNodeId7 = UA_NODEID_STRING(1, "i2c1.relay3");
+    UA_QualifiedName myIntegerName7 = UA_QUALIFIEDNAME(1, "I2C1 / Relay 3");
+    UA_Server_addVariableNode(server, myIntegerNodeId7, parentNodeId,
+                              parentReferenceNodeId, myIntegerName7,
+                              UA_NODEID_NUMERIC(0, UA_NS0ID_BASEDATAVARIABLETYPE), attr7, NULL, NULL);
+ 
 }
 
 /* Connect to variables to physical relays
@@ -134,144 +189,207 @@ static void beforeReadTime(UA_Server *server,
 
 // XXX: having afterWriteTime{0..3} is not needed and maybe with introspection of context we can
 // write only one callback function
-static void afterWriteTime0(UA_Server *server,
+static void afterWriteTimeI2C0_0(UA_Server *server,
+               const UA_NodeId *sessionId, void *sessionContext,
+               const UA_NodeId *nodeId, void *nodeContext,
+               const UA_NumericRange *range, const UA_DataValue *data) {
+    if (data->value.type == &UA_TYPES[UA_TYPES_INT32]) {
+        UA_Int32 hrValue = *(UA_Int32 *)data->value.data;
+	if (hrValue > 0){
+            I2C_0_RELAYS_STATE |= 1UL << 0; 
+            setRelayState(I2C_0_RELAYS_STATE, I2C_0_ADDR);
+	}
+	else {
+            I2C_0_RELAYS_STATE &= ~(1UL << 0);
+            setRelayState(I2C_0_RELAYS_STATE, I2C_0_ADDR);
+	}
+    }
+}
+
+static void afterWriteTimeI2C0_1(UA_Server *server,
+               const UA_NodeId *sessionId, void *sessionContext,
+               const UA_NodeId *nodeId, void *nodeContext,
+               const UA_NumericRange *range, const UA_DataValue *data) {
+    if (data->value.type == &UA_TYPES[UA_TYPES_INT32]) {
+        UA_Int32 hrValue = *(UA_Int32 *)data->value.data;
+	if (hrValue > 0){
+            I2C_0_RELAYS_STATE |= 1UL << 1;
+            setRelayState(I2C_0_RELAYS_STATE, I2C_0_ADDR);
+	}
+	else {
+            I2C_0_RELAYS_STATE &= ~(1UL << 1);
+            setRelayState(I2C_0_RELAYS_STATE, I2C_0_ADDR);
+	}
+    }
+}
+
+static void afterWriteTimeI2C0_2(UA_Server *server,
+               const UA_NodeId *sessionId, void *sessionContext,
+               const UA_NodeId *nodeId, void *nodeContext,
+               const UA_NumericRange *range, const UA_DataValue *data) {
+    if (data->value.type == &UA_TYPES[UA_TYPES_INT32]) {
+        UA_Int32 hrValue = *(UA_Int32 *)data->value.data;
+	if (hrValue > 0){
+            I2C_0_RELAYS_STATE |= 1UL << 2;
+            setRelayState(I2C_0_RELAYS_STATE, I2C_0_ADDR);
+	}
+	else {
+            I2C_0_RELAYS_STATE &= ~(1UL << 2);
+            setRelayState(I2C_0_RELAYS_STATE, I2C_0_ADDR);
+	}
+    }
+}
+
+static void afterWriteTimeI2C0_3(UA_Server *server,
                const UA_NodeId *sessionId, void *sessionContext,
                const UA_NodeId *nodeId, void *nodeContext,
                const UA_NumericRange *range, const UA_DataValue *data) {
-    //UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,  "The variable was updated");
     if (data->value.type == &UA_TYPES[UA_TYPES_INT32]) {
         UA_Int32 hrValue = *(UA_Int32 *)data->value.data;
 	if (hrValue > 0){
-            myrelay |= 1UL << 0; // relay0
-	    setRelayState(myrelay);
+            I2C_0_RELAYS_STATE |= 1UL << 3;
+            setRelayState(I2C_0_RELAYS_STATE, I2C_0_ADDR);
 	}
 	else {
-            myrelay &= ~(1UL << 0); // relay0
-            setRelayState(myrelay);
+            I2C_0_RELAYS_STATE &= ~(1UL << 3);
+            setRelayState(I2C_0_RELAYS_STATE, I2C_0_ADDR);
 	}
     }
 }
 
-static void afterWriteTime1(UA_Server *server,
+
+// I2C1
+static void afterWriteTimeI2C1_0(UA_Server *server,
                const UA_NodeId *sessionId, void *sessionContext,
                const UA_NodeId *nodeId, void *nodeContext,
                const UA_NumericRange *range, const UA_DataValue *data) {
-    //UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,  "The variable was updated");
     if (data->value.type == &UA_TYPES[UA_TYPES_INT32]) {
         UA_Int32 hrValue = *(UA_Int32 *)data->value.data;
 	if (hrValue > 0){
-            myrelay |= 1UL << 1;
-	    setRelayState(myrelay);
+            I2C_1_RELAYS_STATE |= 1UL << 0; 
+            setRelayState(I2C_1_RELAYS_STATE, I2C_1_ADDR);
 	}
 	else {
-            myrelay &= ~(1UL << 1);
-            setRelayState(myrelay);
+            I2C_1_RELAYS_STATE &= ~(1UL << 0);
+            setRelayState(I2C_1_RELAYS_STATE, I2C_1_ADDR);
 	}
     }
 }
 
-static void afterWriteTime2(UA_Server *server,
+static void afterWriteTimeI2C1_1(UA_Server *server,
                const UA_NodeId *sessionId, void *sessionContext,
                const UA_NodeId *nodeId, void *nodeContext,
                const UA_NumericRange *range, const UA_DataValue *data) {
-    //UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,  "The variable was updated");
     if (data->value.type == &UA_TYPES[UA_TYPES_INT32]) {
         UA_Int32 hrValue = *(UA_Int32 *)data->value.data;
 	if (hrValue > 0){
-            myrelay |= 1UL << 2;
-	    setRelayState(myrelay);
+            I2C_1_RELAYS_STATE |= 1UL << 1; 
+            setRelayState(I2C_1_RELAYS_STATE, I2C_1_ADDR);
 	}
 	else {
-            myrelay &= ~(1UL << 2);
-            setRelayState(myrelay);
+            I2C_1_RELAYS_STATE &= ~(1UL << 1);
+            setRelayState(I2C_1_RELAYS_STATE, I2C_1_ADDR);
 	}
     }
 }
 
-static void afterWriteTime3(UA_Server *server,
+static void afterWriteTimeI2C1_2(UA_Server *server,
                const UA_NodeId *sessionId, void *sessionContext,
                const UA_NodeId *nodeId, void *nodeContext,
                const UA_NumericRange *range, const UA_DataValue *data) {
-    //UA_LOG_INFO(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,  "The variable was updated");
     if (data->value.type == &UA_TYPES[UA_TYPES_INT32]) {
         UA_Int32 hrValue = *(UA_Int32 *)data->value.data;
 	if (hrValue > 0){
-            myrelay |= 1UL << 3;
-	    setRelayState(myrelay);
+            I2C_1_RELAYS_STATE |= 1UL << 2; 
+            setRelayState(I2C_1_RELAYS_STATE, I2C_1_ADDR);
 	}
 	else {
-            myrelay &= ~(1UL << 3);
-            setRelayState(myrelay);
+            I2C_1_RELAYS_STATE &= ~(1UL << 2);
+            setRelayState(I2C_1_RELAYS_STATE, I2C_1_ADDR);
+	}
+    }
+}
+
+static void afterWriteTimeI2C1_3(UA_Server *server,
+               const UA_NodeId *sessionId, void *sessionContext,
+               const UA_NodeId *nodeId, void *nodeContext,
+               const UA_NumericRange *range, const UA_DataValue *data) {
+    if (data->value.type == &UA_TYPES[UA_TYPES_INT32]) {
+        UA_Int32 hrValue = *(UA_Int32 *)data->value.data;
+	if (hrValue > 0){
+            I2C_1_RELAYS_STATE |= 1UL << 3; 
+            setRelayState(I2C_1_RELAYS_STATE, I2C_1_ADDR);
+	}
+	else {
+            I2C_1_RELAYS_STATE &= ~(1UL << 3);
+            setRelayState(I2C_1_RELAYS_STATE, I2C_1_ADDR);
 	}
     }
 }
 
 static void addValueCallbackToCurrentTimeVariable(UA_Server *server) {
+    // I2C0
     // relay 0
-    UA_NodeId currentNodeId0 = UA_NODEID_STRING(1, "relay0");
+    UA_NodeId currentNodeId0 = UA_NODEID_STRING(1, "i2c0.relay0");
     UA_ValueCallback callback0 ;
     callback0.onRead = beforeReadTime;
-    callback0.onWrite = afterWriteTime0;
+    callback0.onWrite = afterWriteTimeI2C0_0;
     UA_Server_setVariableNode_valueCallback(server, currentNodeId0, callback0);
     
     // relay 1
-    UA_NodeId currentNodeId1 = UA_NODEID_STRING(1, "relay1");
+    UA_NodeId currentNodeId1 = UA_NODEID_STRING(1, "i2c0.relay1");
     UA_ValueCallback callback1 ;
     callback1.onRead = beforeReadTime;
-    callback1.onWrite = afterWriteTime1;
+    callback1.onWrite = afterWriteTimeI2C0_1;
     UA_Server_setVariableNode_valueCallback(server, currentNodeId1, callback1);
     
     // relay 2
-    UA_NodeId currentNodeId2 = UA_NODEID_STRING(1, "relay2");
+    UA_NodeId currentNodeId2 = UA_NODEID_STRING(1, "i2c0.relay2");
     UA_ValueCallback callback2 ;
     callback2.onRead = beforeReadTime;
-    callback2.onWrite = afterWriteTime2;
+    callback2.onWrite = afterWriteTimeI2C0_2;
     UA_Server_setVariableNode_valueCallback(server, currentNodeId2, callback2);
     
     // relay 3
-    UA_NodeId currentNodeId3 = UA_NODEID_STRING(1, "relay3");
+    UA_NodeId currentNodeId3 = UA_NODEID_STRING(1, "i2c0.relay3");
     UA_ValueCallback callback3 ;
     callback3.onRead = beforeReadTime;
-    callback3.onWrite = afterWriteTime3;
+    callback3.onWrite = afterWriteTimeI2C0_3;
     UA_Server_setVariableNode_valueCallback(server, currentNodeId3, callback3);
-}
 
+    // I2C1
+    // relay 0
+    UA_NodeId currentNodeId4 = UA_NODEID_STRING(1, "i2c1.relay0");
+    UA_ValueCallback callback4;
+    callback4.onRead = beforeReadTime;
+    callback4.onWrite = afterWriteTimeI2C1_0;
+    UA_Server_setVariableNode_valueCallback(server, currentNodeId4, callback4);
     
-/**
- * Now we change the value with the write service. This uses the same service
- * implementation that can also be reached over the network by an OPC UA client.
- */
+    // relay 1
+    UA_NodeId currentNodeId5 = UA_NODEID_STRING(1, "i2c1.relay1");
+    UA_ValueCallback callback5;
+    callback5.onRead = beforeReadTime;
+    callback5.onWrite = afterWriteTimeI2C1_1;
+    UA_Server_setVariableNode_valueCallback(server, currentNodeId5, callback5);
+    
+    // relay 2
+    UA_NodeId currentNodeId6 = UA_NODEID_STRING(1, "i2c1.relay2");
+    UA_ValueCallback callback6;
+    callback6.onRead = beforeReadTime;
+    callback6.onWrite = afterWriteTimeI2C1_2;
+    UA_Server_setVariableNode_valueCallback(server, currentNodeId6, callback6);
     
-static void writeVariable(UA_Server *server) {
-    UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "relay0");
+    // relay 2
+    UA_NodeId currentNodeId7 = UA_NODEID_STRING(1, "i2c1.relay3");
+    UA_ValueCallback callback7;
+    callback7.onRead = beforeReadTime;
+    callback7.onWrite = afterWriteTimeI2C1_3;
+    UA_Server_setVariableNode_valueCallback(server, currentNodeId7, callback7);
     
-    /* Write a different integer value */
-    UA_Int32 myInteger = 0;
-    UA_Variant myVar;
-    UA_Variant_init(&myVar);
-    UA_Variant_setScalar(&myVar, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
-    UA_Server_writeValue(server, myIntegerNodeId, myVar);
-
-    /* Set the status code of the value to an error code. The function
-     * UA_Server_write provides access to the raw service. The above
-     * UA_Server_writeValue is syntactic sugar for writing a specific node
-     * attribute with the write service. */
-    UA_WriteValue wv;
-    UA_WriteValue_init(&wv);
-    wv.nodeId = myIntegerNodeId;
-    wv.attributeId = UA_ATTRIBUTEID_VALUE;
-    wv.value.status = UA_STATUSCODE_BADNOTCONNECTED;
-    wv.value.hasStatus = true;
-    UA_Server_write(server, &wv);
-
-    /* Reset the variable to a good statuscode with a value */
-    wv.value.hasStatus = false;
-    wv.value.value = myVar;
-    wv.value.hasValue = true;
-    UA_Server_write(server, &wv);
 }
 
 
+
 static volatile UA_Boolean running = true;
 
 static void stopHandler(int sign) {
@@ -281,7 +399,7 @@ static void stopHandler(int sign) {
 
 int main(void) {
     // set all relays to OFF at startup
-    setRelayState(0x00);
+    setRelayState(0x00, I2C_0_ADDR);
 
     signal(SIGINT, stopHandler);
     signal(SIGTERM, stopHandler);
@@ -290,12 +408,8 @@ int main(void) {
     UA_ServerConfig_setDefault(UA_Server_getConfig(server));
     UA_ServerConfig* config = UA_Server_getConfig(server);
     config->verifyRequestTimestamp = UA_RULEHANDLING_ACCEPT;
-//#ifdef UA_ENABLE_WEBSOCKET_SERVER
-//    UA_ServerConfig_addNetworkLayerWS(UA_Server_getConfig(server), 7681, 0, 0, NULL, NULL);
-//#endif
 
     addVariable(server);
-    writeVariable(server);
     addValueCallbackToCurrentTimeVariable(server);
 
     UA_StatusCode retval = UA_Server_run(server, &running);
@@ -303,7 +417,7 @@ int main(void) {
     UA_Server_delete(server);
 
     // set all relays to OFF at startup
-    setRelayState(0x00);
+    setRelayState(0x00, I2C_0_ADDR);
 
     return retval == UA_STATUSCODE_GOOD ? EXIT_SUCCESS : EXIT_FAILURE;
 }