diff --git a/slsDetectorServers/ctbDetectorServer/CMakeLists.txt b/slsDetectorServers/ctbDetectorServer/CMakeLists.txt
index e2075eae6..0eeec6b6f 100644
--- a/slsDetectorServers/ctbDetectorServer/CMakeLists.txt
+++ b/slsDetectorServers/ctbDetectorServer/CMakeLists.txt
@@ -16,6 +16,7 @@ add_executable(ctbDetectorServer_virtual
     ../slsDetectorServer/src/LTC2620.c
     ../slsDetectorServer/src/MAX1932.c
     ../slsDetectorServer/src/programFpgaBlackfin.c
+    ../slsDetectorServer/src/communication_virtual.c
 )
 
 include_directories(
diff --git a/slsDetectorServers/ctbDetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/ctbDetectorServer/slsDetectorFunctionList.c
index e7228fd26..4e87de588 100755
--- a/slsDetectorServers/ctbDetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/ctbDetectorServer/slsDetectorFunctionList.c
@@ -10,6 +10,9 @@
 #include "MAX1932.h"    // hv
 #include "INA226.h"     // i2c
 #include "ALTERA_PLL.h" // pll
+#ifdef VIRTUAL
+#include "communication_virtual.h"
+#endif
 
 #include <string.h>
 #include <unistd.h>     // usleep
@@ -30,6 +33,7 @@ extern uint64_t udpFrameNumber;
 extern uint32_t udpPacketNumber;
 
 // Global variable from communication_funcs.c
+extern int isControlServer;
 extern void getMacAddressinString(char* cmac, int size, uint64_t mac);
 extern void getIpAddressinString(char* cip, uint32_t ip);
 
@@ -427,6 +431,12 @@ void initStopServer() {
 		LOG(logERROR, ("Stop Server: Map Fail. Dangerous to continue. Goodbye!\n"));
 		exit(EXIT_FAILURE);
 	}
+#ifdef VIRTUAL
+	virtual_stop = 0;
+	if (!isControlServer) {
+		ComVirtual_setStop(virtual_stop);
+	}
+#endif
 }
 
 
@@ -469,7 +479,12 @@ void setupDetector() {
     digitalEnable = 0;
     naSamples = 1;
     ndSamples = 1;
-
+#ifdef VIRTUAL
+	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
+#endif
 
     ALTERA_PLL_ResetPLLAndReconfiguration();
     resetCore();
@@ -2153,10 +2168,21 @@ int startStateMachine(){
 	}
 	LOG(logINFOBLUE, ("Starting State Machine\n"));
     virtual_status = 1;
-	virtual_stop = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+		virtual_stop = ComVirtual_getStop();
+		if (virtual_stop != 0) {
+			LOG(logERROR, ("Cant start acquisition. "
+			"Stop server has not updated stop status to 0\n"));
+			return FAIL;
+		}
+	}
 	if(pthread_create(&pthread_virtual_tid, NULL, &start_timer, NULL)) {
 		LOG(logERROR, ("Could not start Virtual acquisition thread\n"));
 		virtual_status = 0;
+		if (isControlServer) {
+			ComVirtual_setStatus(virtual_status);
+		}	
 		return FAIL;
 	}
 	LOG(logINFOGREEN, ("Virtual Acquisition started\n"));
@@ -2190,6 +2216,10 @@ int startStateMachine(){
 
 #ifdef VIRTUAL
 void* start_timer(void* arg) {
+	if (!isControlServer) {
+		return NULL;
+	}
+
 	int64_t periodNs = getPeriod();
 	int numFrames = (getNumFrames() *
 						getNumTriggers() );
@@ -2216,6 +2246,8 @@ void* start_timer(void* arg) {
         // loop over number of frames
         for(frameNr = 0; frameNr != numFrames; ++frameNr ) {
 
+			// update the virtual stop from stop server
+			virtual_stop = ComVirtual_getStop();
             //check if virtual_stop is high
             if(virtual_stop == 1){
                 break;
@@ -2268,6 +2300,9 @@ void* start_timer(void* arg) {
 	closeUDPSocket(0);
 
 	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
 	LOG(logINFOBLUE, ("Finished Acquiring\n"));        
 	return NULL;
 }
@@ -2276,7 +2311,18 @@ void* start_timer(void* arg) {
 int stopStateMachine(){
 	LOG(logINFORED, ("Stopping State Machine\n"));
 #ifdef VIRTUAL
-	virtual_stop = 0;
+	if (!isControlServer) {
+		virtual_stop = 1;
+		ComVirtual_setStop(virtual_stop);
+		// read till status is idle
+		int tempStatus = 1;
+		while(tempStatus == 1) {
+			tempStatus = ComVirtual_getStatus();
+		}
+		virtual_stop = 0;
+		ComVirtual_setStop(virtual_stop);
+		LOG(logINFO, ("Stopped State Machine\n"));
+	}	
 	return OK;
 #endif
 	//stop state machine
@@ -2295,7 +2341,10 @@ int stopStateMachine(){
 
 enum runStatus getRunStatus(){
 #ifdef VIRTUAL
-	if(virtual_status == 0){
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
+	if(virtual_status == 0) {
 		LOG(logINFOBLUE, ("Status: IDLE\n"));
 		return IDLE;
 	}else{
@@ -2567,6 +2616,9 @@ int readFrameFromFifo() {
 
 uint32_t runBusy() {
 #ifdef VIRTUAL
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
     return virtual_status;
 #endif
 	uint32_t s = (bus_r(STATUS_REG) & STATUS_RN_BSY_MSK);
diff --git a/slsDetectorServers/eigerDetectorServer/CMakeLists.txt b/slsDetectorServers/eigerDetectorServer/CMakeLists.txt
index 912f21bbf..b068ef4c4 100644
--- a/slsDetectorServers/eigerDetectorServer/CMakeLists.txt
+++ b/slsDetectorServers/eigerDetectorServer/CMakeLists.txt
@@ -5,6 +5,7 @@ set(src
     ../slsDetectorServer/src/communication_funcs.c
     ../slsDetectorServer/src/communication_funcs_UDP.c
     ../slsDetectorServer/src/common.c
+    ../slsDetectorServer/src/communication_virtual.c
 )
 
 include_directories(
diff --git a/slsDetectorServers/eigerDetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/eigerDetectorServer/slsDetectorFunctionList.c
index 1b28e1efb..f657011a7 100755
--- a/slsDetectorServers/eigerDetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/eigerDetectorServer/slsDetectorFunctionList.c
@@ -6,6 +6,8 @@
 #ifndef VIRTUAL
 #include "FebControl.h"
 #include "Beb.h"
+#else
+#include "communication_virtual.h"
 #endif
 
 #include <unistd.h> //to gethostname
@@ -71,6 +73,9 @@ int eiger_tau_ns = 0;
 
 
 #ifdef VIRTUAL
+pthread_t virtual_tid;
+int virtual_status=0;
+int virtual_stop = 0;
 //values for virtual server
 int64_t eiger_virtual_exptime = 0;
 int64_t eiger_virtual_subexptime = 0;
@@ -84,11 +89,8 @@ int eiger_virtual_transmission_delay_left=0;
 int eiger_virtual_transmission_delay_right=0;
 int eiger_virtual_transmission_delay_frame=0;
 int eiger_virtual_transmission_flowcontrol_10g=0;
-int eiger_virtual_status=0;
 int eiger_virtual_activate=1;
-pthread_t eiger_virtual_tid;
-int eiger_virtual_stop = 0;
-uint64_t eiger_virtual_startingframenumber = 0;
+uint64_t eiger_virtual_startingframenumber = 1;
 int eiger_virtual_detPos[2] = {0, 0};
 int eiger_virtual_test_mode = 0;
 int eiger_virtual_quad_mode = 0;
@@ -353,6 +355,10 @@ void initControlServer() {
 void initStopServer() {
 #ifdef VIRTUAL
 	getModuleConfiguration();
+	virtual_stop = 0;
+	if (!isControlServer) {
+		ComVirtual_setStop(virtual_stop);
+	}
 	return;
 #else
 	getModuleConfiguration();
@@ -469,6 +475,12 @@ void setupDetector() {
 			}
 		}
 	}
+#ifdef VIRTUAL
+	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
+#endif
 
 	LOG(logINFOBLUE, ("Setting Default Parameters\n"));
 	//setting default measurement parameters
@@ -1803,11 +1815,22 @@ int startStateMachine() {
 		return FAIL;
 	}
 	LOG(logINFOBLUE, ("Starting State Machine\n"));
-	eiger_virtual_status = 1;
-	eiger_virtual_stop = 0;
-	if (pthread_create(&eiger_virtual_tid, NULL, &start_timer, NULL)) {
+	virtual_status = 1;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+		virtual_stop = ComVirtual_getStop();
+		if (virtual_stop != 0) {
+			LOG(logERROR, ("Cant start acquisition. "
+			"Stop server has not updated stop status to 0\n"));
+			return FAIL;
+		}
+	}
+	if (pthread_create(&virtual_tid, NULL, &start_timer, NULL)) {
 		LOG(logERROR, ("Could not start Virtual acquisition thread\n"));
-		eiger_virtual_status = 0;
+		virtual_status = 0;
+		if (isControlServer) {
+			ComVirtual_setStatus(virtual_status);
+		}	
 		return FAIL;
 	}
 	LOG(logINFO ,("Virtual Acquisition started\n"));
@@ -1841,6 +1864,10 @@ int startStateMachine() {
 
 #ifdef VIRTUAL
 void* start_timer(void* arg) {
+	if (!isControlServer) {
+		return NULL;
+	}
+
 	int64_t periodNs = eiger_virtual_period;
 	int numFrames = nimages_per_request;
 	int64_t expUs = eiger_virtual_exptime / 1000;
@@ -1894,14 +1921,19 @@ void* start_timer(void* arg) {
 	
 	// Send data
 	{
-		int frameNr = 1;
+		uint64_t frameNr = 0;
+		getStartingFrameNumber(&frameNr);
         // loop over number of frames
-		for(frameNr = 1; frameNr <= numFrames; ++frameNr ) {
+		int iframes = 0;
+		for(iframes = 0; iframes != numFrames; ++iframes ) {
 
 			usleep(eiger_virtual_transmission_delay_frame);
 
+			// update the virtual stop from stop server
+			virtual_stop = ComVirtual_getStop();
 			//check if virtual_stop is high
-			if(eiger_virtual_stop == 1){
+			if(virtual_stop == 1){
+				setStartingFrameNumber(frameNr + iframes + 1);
 				break;
 			}
 
@@ -1923,7 +1955,7 @@ void* start_timer(void* arg) {
 					sls_detector_header* header = (sls_detector_header*)(packetData);
 					header->detType = 3;//(uint16_t)myDetectorType; updated when firmware updates
 					header->version = SLS_DETECTOR_HEADER_VERSION - 1;								
-					header->frameNumber = frameNr;
+					header->frameNumber = frameNr + iframes;
 					header->packetNumber = i;
 					header->row = row;
 					header->column = colLeft;
@@ -1933,7 +1965,7 @@ void* start_timer(void* arg) {
 					header = (sls_detector_header*)(packetData2);
 					header->detType = 3;//(uint16_t)myDetectorType; updated when firmware updates
 					header->version = SLS_DETECTOR_HEADER_VERSION - 1;								
-					header->frameNumber = frameNr;
+					header->frameNumber = frameNr + iframes;
 					header->packetNumber = i;
 					header->row = row;
 					header->column = colRight;
@@ -1979,25 +2011,29 @@ void* start_timer(void* arg) {
 					sendUDPPacket(1, packetData2, packetsize);
 				}
 			}
-			LOG(logINFO, ("Sent frame: %d\n", frameNr));
+			LOG(logINFO, ("Sent frame: %d\n", iframes));
 			clock_gettime(CLOCK_REALTIME, &end);
 			int64_t timeNs = ((end.tv_sec - begin.tv_sec) * 1E9 +
 					(end.tv_nsec - begin.tv_nsec));
 
 			// sleep for (period - exptime)
-			if (frameNr < numFrames) { // if there is a next frame
+			if (iframes < numFrames) { // if there is a next frame
 				if (periodNs > timeNs) {
 					usleep((periodNs - timeNs)/ 1000);
 				}
 			}
 		}
+		setStartingFrameNumber(frameNr + numFrames);
 	}
 	
 	
 	closeUDPSocket(0);
 	closeUDPSocket(1);
 	
-	eiger_virtual_status = 0;
+	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
 	LOG(logINFOBLUE, ("Finished Acquiring\n"));
 	return NULL;
 }
@@ -2009,7 +2045,18 @@ void* start_timer(void* arg) {
 int stopStateMachine() {
 	LOG(logINFORED, ("Going to stop acquisition\n"));
 #ifdef VIRTUAL
-	eiger_virtual_stop = 0;
+	if (!isControlServer) {
+		virtual_stop = 1;
+		ComVirtual_setStop(virtual_stop);
+		// read till status is idle
+		int tempStatus = 1;
+		while(tempStatus == 1) {
+			tempStatus = ComVirtual_getStatus();
+		}
+		virtual_stop = 0;
+		ComVirtual_setStop(virtual_stop);
+		LOG(logINFO, ("Stopped State Machine\n"));
+	}	
 	return OK;
 #else
 	if ((Feb_Control_StopAcquisition() != STATUS_IDLE) || (!Beb_StopAcquisition()) ) {
@@ -2069,7 +2116,10 @@ int startReadOut() {
 
 enum runStatus getRunStatus() {
 #ifdef VIRTUAL
-	if (eiger_virtual_status == 0) {
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
+	if (virtual_status == 0) {
 		LOG(logINFO, ("Status: IDLE\n"));
 		return IDLE;
 	} else {
@@ -2100,7 +2150,7 @@ enum runStatus getRunStatus() {
 void readFrame(int *ret, char *mess) {
 #ifdef VIRTUAL
 	// wait for status to be done
-	while(eiger_virtual_status == 1){
+	while(virtual_status == 1){
 		usleep(500);
 	}
 	LOG(logINFOGREEN, ("acquisition successfully finished\n"));
diff --git a/slsDetectorServers/gotthard2DetectorServer/CMakeLists.txt b/slsDetectorServers/gotthard2DetectorServer/CMakeLists.txt
index 7d2d6ed01..6b5cdbf5e 100644
--- a/slsDetectorServers/gotthard2DetectorServer/CMakeLists.txt
+++ b/slsDetectorServers/gotthard2DetectorServer/CMakeLists.txt
@@ -11,6 +11,7 @@ add_executable(gotthard2DetectorServer_virtual
     ../slsDetectorServer/src/ALTERA_PLL_CYCLONE10.c    
     ../slsDetectorServer/src/ASIC_Driver.c
     ../slsDetectorServer/src/programFpgaNios.c
+    ../slsDetectorServer/src/communication_virtual.c
 )
 
 include_directories(
diff --git a/slsDetectorServers/gotthard2DetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/gotthard2DetectorServer/slsDetectorFunctionList.c
index 7ccae09df..bf9eff71f 100644
--- a/slsDetectorServers/gotthard2DetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/gotthard2DetectorServer/slsDetectorFunctionList.c
@@ -9,6 +9,7 @@
 #include "ASIC_Driver.h"
 #ifdef VIRTUAL
 #include "communication_funcs_UDP.h"
+#include "communication_virtual.h"
 #endif
 
 #include <string.h>
@@ -27,6 +28,7 @@ extern udpStruct udpDetails;
 extern const enum detectorType myDetectorType;
 
 // Global variable from communication_funcs.c
+extern int isControlServer;
 extern void getMacAddressinString(char* cmac, int size, uint64_t mac);
 extern void getIpAddressinString(char* cip, uint32_t ip);
 
@@ -337,6 +339,12 @@ void initStopServer() {
 		LOG(logERROR, ("Stop Server: Map Fail. Dangerous to continue. Goodbye!\n"));
 		exit(EXIT_FAILURE);
 	}
+#ifdef VIRTUAL
+	virtual_stop = 0;
+	if (!isControlServer) {
+		ComVirtual_setStop(virtual_stop);
+	}
+#endif
 }
 
 
@@ -386,7 +394,12 @@ void setupDetector() {
 			}
 		}	
 	}
-
+#ifdef VIRTUAL
+	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
+#endif
 
 	// pll defines
 	ALTERA_PLL_C10_SetDefines(REG_OFFSET, BASE_READOUT_PLL, BASE_SYSTEM_PLL, PLL_RESET_REG, PLL_RESET_REG, PLL_RESET_READOUT_MSK, PLL_RESET_SYSTEM_MSK, READOUT_PLL_VCO_FREQ_HZ, SYSTEM_PLL_VCO_FREQ_HZ);
@@ -2006,10 +2019,21 @@ int startStateMachine(){
 	LOG(logINFOBLUE, ("Starting State Machine\n"));
 	// set status to running
 	virtual_status = 1;
-	virtual_stop = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+		virtual_stop = ComVirtual_getStop();
+		if (virtual_stop != 0) {
+			LOG(logERROR, ("Cant start acquisition. "
+			"Stop server has not updated stop status to 0\n"));
+			return FAIL;
+		}
+	}
 	if(pthread_create(&pthread_virtual_tid, NULL, &start_timer, NULL)) {
 		LOG(logERROR, ("Could not start Virtual acquisition thread\n"));
 		virtual_status = 0;
+		if (isControlServer) {
+			ComVirtual_setStatus(virtual_status);
+		}	
 		return FAIL;
 	}
 	LOG(logINFOGREEN, ("Virtual Acquisition started\n"));
@@ -2028,6 +2052,10 @@ int startStateMachine(){
 
 #ifdef VIRTUAL
 void* start_timer(void* arg) {
+	if (!isControlServer) {
+		return NULL;
+	}
+
 	int numRepeats = getNumTriggers();
 	if (getTiming() == AUTO_TIMING) {
 		if (burstMode == BURST_OFF) {
@@ -2067,6 +2095,8 @@ void* start_timer(void* arg) {
 			// loop over number of frames
     		for(frameNr = 0; frameNr != numFrames; ++frameNr ) {
 			
+				// update the virtual stop from stop server
+				virtual_stop = ComVirtual_getStop();
 				//check if virtual_stop is high
 				if(virtual_stop == 1){
 					break;
@@ -2125,6 +2155,9 @@ void* start_timer(void* arg) {
 	closeUDPSocket(0);
 
 	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
 	LOG(logINFOBLUE, ("Finished Acquiring\n"));
 	return NULL;
 }
@@ -2134,7 +2167,18 @@ void* start_timer(void* arg) {
 int stopStateMachine(){
 	LOG(logINFORED, ("Stopping State Machine\n"));
 #ifdef VIRTUAL
-	virtual_stop = 0;
+	if (!isControlServer) {
+		virtual_stop = 1;
+		ComVirtual_setStop(virtual_stop);
+		// read till status is idle
+		int tempStatus = 1;
+		while(tempStatus == 1) {
+			tempStatus = ComVirtual_getStatus();
+		}
+		virtual_stop = 0;
+		ComVirtual_setStop(virtual_stop);
+		LOG(logINFO, ("Stopped State Machine\n"));
+	}	
 	return OK;
 #endif
     //stop state machine
@@ -2145,7 +2189,10 @@ int stopStateMachine(){
 
 enum runStatus getRunStatus(){
 #ifdef VIRTUAL
-	if(virtual_status == 0){
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
+	if(virtual_status == 0) {
 		LOG(logINFOBLUE, ("Status: IDLE\n"));
 		return IDLE;
 	}else{
@@ -2219,6 +2266,9 @@ void readFrame(int *ret, char *mess) {
 
 u_int32_t runBusy() {
 #ifdef VIRTUAL
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
     return virtual_status;
 #endif
 	u_int32_t s = (bus_r(FLOW_STATUS_REG) & FLOW_STATUS_RUN_BUSY_MSK);
diff --git a/slsDetectorServers/gotthardDetectorServer/CMakeLists.txt b/slsDetectorServers/gotthardDetectorServer/CMakeLists.txt
index 8d38278af..eb2c60299 100644
--- a/slsDetectorServers/gotthardDetectorServer/CMakeLists.txt
+++ b/slsDetectorServers/gotthardDetectorServer/CMakeLists.txt
@@ -10,6 +10,7 @@ add_executable(gotthardDetectorServer_virtual
     ../slsDetectorServer/src/common.c
     ../slsDetectorServer/src/commonServerFunctions.c    
     ../slsDetectorServer/src/communication_funcs_UDP.c    
+    ../slsDetectorServer/src/communication_virtual.c
 )
 
 include_directories(
diff --git a/slsDetectorServers/gotthardDetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/gotthardDetectorServer/slsDetectorFunctionList.c
index 959dd1c53..9a267e246 100755
--- a/slsDetectorServers/gotthardDetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/gotthardDetectorServer/slsDetectorFunctionList.c
@@ -6,6 +6,7 @@
 #include "LTC2620.h"    // dacs
 #ifdef VIRTUAL
 #include "communication_funcs_UDP.h"
+#include "communication_virtual.h"
 #endif
 
 #include "string.h"
@@ -23,6 +24,7 @@ extern const enum detectorType myDetectorType;
 int phaseShift = DEFAULT_PHASE_SHIFT;
 
 // Global variable from communication_funcs.c
+extern int isControlServer;
 extern void getMacAddressinString(char* cmac, int size, uint64_t mac);
 extern void getIpAddressinString(char* cip, uint32_t ip);
 
@@ -354,6 +356,12 @@ void initStopServer() {
 		LOG(logERROR, ("Stop Server: Map Fail. Dangerous to continue. Goodbye!\n"));
 		exit(EXIT_FAILURE);
 	}
+#ifdef VIRTUAL
+	virtual_stop = 0;
+	if (!isControlServer) {
+		ComVirtual_setStop(virtual_stop);
+	}
+#endif
 }
 
 
@@ -362,6 +370,13 @@ void initStopServer() {
 void setupDetector() {
     LOG(logINFO, ("This Server is for 1 Gotthard module (1280 channels)\n"));
 
+#ifdef VIRTUAL
+	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
+#endif
+
     // Initialization
     setPhaseShiftOnce();
 
@@ -1496,10 +1511,21 @@ int startStateMachine(){
 	}
 	LOG(logINFOBLUE, ("Starting State Machine\n"));
     virtual_status = 1;
-	virtual_stop = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+		virtual_stop = ComVirtual_getStop();
+		if (virtual_stop != 0) {
+			LOG(logERROR, ("Cant start acquisition. "
+			"Stop server has not updated stop status to 0\n"));
+			return FAIL;
+		}
+	}
 	if(pthread_create(&pthread_virtual_tid, NULL, &start_timer, NULL)) {
 		LOG(logERROR, ("Could not start Virtual acquisition thread\n"));
 		virtual_status = 0;
+		if (isControlServer) {
+			ComVirtual_setStatus(virtual_status);
+		}	
 		return FAIL;
 	}
 	LOG(logINFOGREEN, ("Virtual Acquisition started\n"));
@@ -1519,6 +1545,10 @@ int startStateMachine(){
 
 #ifdef VIRTUAL
 void* start_timer(void* arg) {
+	if (!isControlServer) {
+		return NULL;
+	}
+
 	int64_t periodNs = getPeriod();
 	int numFrames = (getNumFrames() *
 						getNumTriggers() );
@@ -1549,6 +1579,8 @@ void* start_timer(void* arg) {
         // loop over number of frames
         for(frameNr = 0; frameNr != numFrames; ++frameNr ) {
 
+			// update the virtual stop from stop server
+			virtual_stop = ComVirtual_getStop();
             //check if virtual_stop is high
             if(virtual_stop == 1){
                 break;
@@ -1595,6 +1627,9 @@ void* start_timer(void* arg) {
 	closeUDPSocket(0);
 
 	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
 	LOG(logINFOBLUE, ("Finished Acquiring\n"));        
 	return NULL;
 }
@@ -1603,7 +1638,18 @@ void* start_timer(void* arg) {
 int stopStateMachine(){
 	LOG(logINFORED, ("Stopping State Machine\n"));
 #ifdef VIRTUAL
-	virtual_stop = 0;
+	if (!isControlServer) {
+		virtual_stop = 1;
+		ComVirtual_setStop(virtual_stop);
+		// read till status is idle
+		int tempStatus = 1;
+		while(tempStatus == 1) {
+			tempStatus = ComVirtual_getStatus();
+		}
+		virtual_stop = 0;
+		ComVirtual_setStop(virtual_stop);
+		LOG(logINFO, ("Stopped State Machine\n"));
+	}	
 	return OK;
 #endif
 	//stop state machine
@@ -1625,7 +1671,10 @@ int stopStateMachine(){
 
 enum runStatus getRunStatus(){
 #ifdef VIRTUAL
-	if(virtual_status == 0){
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
+	if(virtual_status == 0) {
 		LOG(logINFOBLUE, ("Status: IDLE\n"));
 		return IDLE;
 	}else{
@@ -1727,6 +1776,9 @@ void readFrame(int *ret, char *mess){
 
 u_int32_t runBusy() {
 #ifdef VIRTUAL
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
     return virtual_status;
 #endif
 	return runState(logDEBUG1) & STATUS_RN_BSY_MSK;
diff --git a/slsDetectorServers/jungfrauDetectorServer/CMakeLists.txt b/slsDetectorServers/jungfrauDetectorServer/CMakeLists.txt
index 0215225ee..b3aac94aa 100644
--- a/slsDetectorServers/jungfrauDetectorServer/CMakeLists.txt
+++ b/slsDetectorServers/jungfrauDetectorServer/CMakeLists.txt
@@ -12,6 +12,7 @@ add_executable(jungfrauDetectorServer_virtual
     ../slsDetectorServer/src/MAX1932.c
     ../slsDetectorServer/src/programFpgaBlackfin.c
     ../slsDetectorServer/src/communication_funcs_UDP.c    
+    ../slsDetectorServer/src/communication_virtual.c
 )
 
 target_include_directories(jungfrauDetectorServer_virtual
diff --git a/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.c
index 0d5237c6f..42a30b2b0 100755
--- a/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/jungfrauDetectorServer/slsDetectorFunctionList.c
@@ -8,6 +8,7 @@
 #include "common.h"
 #ifdef VIRTUAL
 #include "communication_funcs_UDP.h"
+#include "communication_virtual.h"
 #endif
 
 #include <string.h>
@@ -25,6 +26,7 @@ extern udpStruct udpDetails;
 extern const enum detectorType myDetectorType;
 
 // Global variable from communication_funcs.c
+extern int isControlServer;
 extern void getMacAddressinString(char* cmac, int size, uint64_t mac);
 extern void getIpAddressinString(char* cip, uint32_t ip);
 
@@ -373,6 +375,12 @@ void initStopServer() {
 		LOG(logERROR, ("Stop Server: Map Fail. Dangerous to continue. Goodbye!\n"));
 		exit(EXIT_FAILURE);
 	}
+#ifdef VIRTUAL
+	virtual_stop = 0;
+	if (!isControlServer) {
+		ComVirtual_setStop(virtual_stop);
+	}
+#endif
 }
 
 
@@ -394,6 +402,13 @@ void setupDetector() {
             clkPhase[i] = 0;
         }
 	}
+#ifdef VIRTUAL
+	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
+#endif
+
     ALTERA_PLL_ResetPLL();
 	resetCore();
 	resetPeripheral();
@@ -545,16 +560,24 @@ int selectStoragecellStart(int pos) {
 
 int setStartingFrameNumber(uint64_t value) {
 	LOG(logINFO, ("Setting starting frame number: %llu\n",(long long unsigned int)value));
+#ifdef VIRTUAL
+	setU64BitReg(value, FRAME_NUMBER_LSB_REG, FRAME_NUMBER_MSB_REG);
+#else
 	// decrement is for firmware
 	setU64BitReg(value - 1, FRAME_NUMBER_LSB_REG, FRAME_NUMBER_MSB_REG);
 	// need to set it twice for the firmware to catch
 	setU64BitReg(value - 1, FRAME_NUMBER_LSB_REG, FRAME_NUMBER_MSB_REG);
+#endif
 	return OK;
 }
 
 int getStartingFrameNumber(uint64_t* retval) {
+#ifdef VIRTUAL
+	*retval = getU64BitReg(FRAME_NUMBER_LSB_REG, FRAME_NUMBER_MSB_REG);
+#else
 	// increment is for firmware
 	*retval = (getU64BitReg(GET_FRAME_NUMBER_LSB_REG, GET_FRAME_NUMBER_MSB_REG) + 1);
+#endif
 	return OK;
 }
 
@@ -1625,10 +1648,21 @@ int startStateMachine(){
 	}
 	LOG(logINFOBLUE, ("starting state machine\n"));
 	virtual_status = 1;
-	virtual_stop = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+		virtual_stop = ComVirtual_getStop();
+		if (virtual_stop != 0) {
+			LOG(logERROR, ("Cant start acquisition. "
+			"Stop server has not updated stop status to 0\n"));
+			return FAIL;
+		}
+	}
 	if(pthread_create(&pthread_virtual_tid, NULL, &start_timer, NULL)) {
 		LOG(logERROR, ("Could not start Virtual acquisition thread\n"));
 		virtual_status = 0;
+		if (isControlServer) {
+			ComVirtual_setStatus(virtual_status);
+		}	
 		return FAIL;
 	}
 	LOG(logINFOGREEN, ("Virtual Acquisition started\n"));
@@ -1649,6 +1683,10 @@ int startStateMachine(){
 
 #ifdef VIRTUAL
 void* start_timer(void* arg) {
+	if (!isControlServer) {
+		return NULL;
+	}
+
 	int numInterfaces = getNumberofUDPInterfaces();
 	int64_t periodNs = getPeriod();
 	int numFrames = (getNumFrames() *
@@ -1675,13 +1713,18 @@ void* start_timer(void* arg) {
 	
 	// Send data
 	{
-		int frameNr = 0;
-		for(frameNr = 0; frameNr != numFrames; ++frameNr ) {
+		uint64_t frameNr = 0;
+		getStartingFrameNumber(&frameNr);
+		int iframes = 0;
+		for(iframes = 0; iframes != numFrames; ++iframes ) {
 
 			usleep(transmissionDelayUs);
 
+			// update the virtual stop from stop server
+			virtual_stop = ComVirtual_getStop();
 			//check if virtual_stop is high
 			if(virtual_stop == 1){
+				setStartingFrameNumber(frameNr + iframes + 1);
 				break;
 			}
 
@@ -1702,7 +1745,7 @@ void* start_timer(void* arg) {
 					sls_detector_header* header = (sls_detector_header*)(packetData);
 					header->detType = (uint16_t)myDetectorType;
 					header->version = SLS_DETECTOR_HEADER_VERSION - 1;								
-					header->frameNumber = frameNr;
+					header->frameNumber = frameNr + iframes;
 					header->packetNumber = i;
 					header->modId = 0;
 					header->row = detPos[2];
@@ -1737,18 +1780,19 @@ void* start_timer(void* arg) {
 					}
 				}
 			}
-			LOG(logINFO, ("Sent frame: %d\n", frameNr));
+			LOG(logINFO, ("Sent frame: %d\n", iframes));
 			clock_gettime(CLOCK_REALTIME, &end);
 			int64_t timeNs = ((end.tv_sec - begin.tv_sec) * 1E9 +
 					(end.tv_nsec - begin.tv_nsec));
 	
 			// sleep for (period - exptime)
-			if (frameNr < numFrames) { // if there is a next frame
+			if (iframes < numFrames) { // if there is a next frame
 				if (periodNs > timeNs) {
 					usleep((periodNs - timeNs)/ 1000);
 				}
 			}
 		}
+		setStartingFrameNumber(frameNr + numFrames);
 	}
 		
 	closeUDPSocket(0);
@@ -1757,6 +1801,9 @@ void* start_timer(void* arg) {
 	}
 
 	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
 	LOG(logINFOBLUE, ("Finished Acquiring\n"));
 	return NULL;
 }
@@ -1765,7 +1812,18 @@ void* start_timer(void* arg) {
 int stopStateMachine(){
 	LOG(logINFORED, ("Stopping State Machine\n"));
 #ifdef VIRTUAL
-	virtual_stop = 0;
+	if (!isControlServer) {
+		virtual_stop = 1;
+		ComVirtual_setStop(virtual_stop);
+		// read till status is idle
+		int tempStatus = 1;
+		while(tempStatus == 1) {
+			tempStatus = ComVirtual_getStatus();
+		}
+		virtual_stop = 0;
+		ComVirtual_setStop(virtual_stop);
+		LOG(logINFO, ("Stopped State Machine\n"));
+	}	
 	return OK;
 #endif
 	//stop state machine
@@ -1783,7 +1841,10 @@ int stopStateMachine(){
 
 enum runStatus getRunStatus(){
 #ifdef VIRTUAL
-	if(virtual_status == 0){
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
+	if(virtual_status == 0) {
 		LOG(logINFOBLUE, ("Status: IDLE\n"));
 		return IDLE;
 	}else{
@@ -1857,6 +1918,9 @@ void readFrame(int *ret, char *mess){
 
 u_int32_t runBusy() {
 #ifdef VIRTUAL
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
     return virtual_status;
 #endif
 	u_int32_t s = (bus_r(STATUS_REG) & RUN_BUSY_MSK);
diff --git a/slsDetectorServers/moenchDetectorServer/CMakeLists.txt b/slsDetectorServers/moenchDetectorServer/CMakeLists.txt
index b1acba756..ff6dd94a0 100644
--- a/slsDetectorServers/moenchDetectorServer/CMakeLists.txt
+++ b/slsDetectorServers/moenchDetectorServer/CMakeLists.txt
@@ -14,6 +14,7 @@ add_executable(moenchDetectorServer_virtual
     ../slsDetectorServer/src/MAX1932.c
     ../slsDetectorServer/src/programFpgaBlackfin.c   
     ../slsDetectorServer/src/readDefaultPattern.c         
+    ../slsDetectorServer/src/communication_virtual.c
 )
 
 include_directories(
diff --git a/slsDetectorServers/moenchDetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/moenchDetectorServer/slsDetectorFunctionList.c
index 59f0763ee..9562adec2 100755
--- a/slsDetectorServers/moenchDetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/moenchDetectorServer/slsDetectorFunctionList.c
@@ -8,6 +8,9 @@
 #include "MAX1932.h"    // hv
 #include "ALTERA_PLL.h" // pll
 #include "common.h"
+#ifdef VIRTUAL
+#include "communication_virtual.h"
+#endif
 
 #include <string.h>
 #include <unistd.h>     // usleep
@@ -28,6 +31,7 @@ extern uint64_t udpFrameNumber;
 extern uint32_t udpPacketNumber;
 
 // Global variable from communication_funcs.c
+extern int isControlServer;
 extern void getMacAddressinString(char* cmac, int size, uint64_t mac);
 extern void getIpAddressinString(char* cip, uint32_t ip);
 
@@ -422,6 +426,12 @@ void initStopServer() {
 		LOG(logERROR, ("Stop Server: Map Fail. Dangerous to continue. Goodbye!\n"));
 		exit(EXIT_FAILURE);
 	}
+#ifdef VIRTUAL
+	virtual_stop = 0;
+	if (!isControlServer) {
+		ComVirtual_setStop(virtual_stop);
+	}
+#endif
 }
 
 
@@ -474,6 +484,12 @@ void setupDetector() {
     adcEnableMask_1g = 0;
     adcEnableMask_10g = 0;
     nSamples = 1;
+#ifdef VIRTUAL
+	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
+#endif
 
     ALTERA_PLL_ResetPLLAndReconfiguration();
     resetCore();
@@ -1815,10 +1831,21 @@ int startStateMachine(){
 	}
 	LOG(logINFOBLUE, ("Starting State Machine\n"));
     virtual_status = 1;
-	virtual_stop = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+		virtual_stop = ComVirtual_getStop();
+		if (virtual_stop != 0) {
+			LOG(logERROR, ("Cant start acquisition. "
+			"Stop server has not updated stop status to 0\n"));
+			return FAIL;
+		}
+	}
 	if(pthread_create(&pthread_virtual_tid, NULL, &start_timer, NULL)) {
 		LOG(logERROR, ("Could not start Virtual acquisition thread\n"));
 		virtual_status = 0;
+		if (isControlServer) {
+			ComVirtual_setStatus(virtual_status);
+		}	
 		return FAIL;
 	}
 	LOG(logINFOGREEN, ("Virtual Acquisition started\n"));
@@ -1852,6 +1879,10 @@ int startStateMachine(){
 
 #ifdef VIRTUAL
 void* start_timer(void* arg) {
+	if (!isControlServer) {
+		return NULL;
+	}
+
 	int64_t periodNs = getPeriod();
 	int numFrames = (getNumFrames() *
 						getNumTriggers() );
@@ -1878,6 +1909,8 @@ void* start_timer(void* arg) {
         // loop over number of frames
         for(frameNr = 0; frameNr != numFrames; ++frameNr ) {
 
+			// update the virtual stop from stop server
+			virtual_stop = ComVirtual_getStop();
             //check if virtual_stop is high
             if(virtual_stop == 1){
                 break;
@@ -1929,6 +1962,9 @@ void* start_timer(void* arg) {
 	closeUDPSocket(0);
 
 	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
 	LOG(logINFOBLUE, ("Finished Acquiring\n"));        
 	return NULL;
 }
@@ -1937,7 +1973,18 @@ void* start_timer(void* arg) {
 int stopStateMachine(){
 	LOG(logINFORED, ("Stopping State Machine\n"));
 #ifdef VIRTUAL
-	virtual_stop = 0;
+	if (!isControlServer) {
+		virtual_stop = 1;
+		ComVirtual_setStop(virtual_stop);
+		// read till status is idle
+		int tempStatus = 1;
+		while(tempStatus == 1) {
+			tempStatus = ComVirtual_getStatus();
+		}
+		virtual_stop = 0;
+		ComVirtual_setStop(virtual_stop);
+		LOG(logINFO, ("Stopped State Machine\n"));
+	}	
 	return OK;
 #endif
 	//stop state machine
@@ -1956,7 +2003,10 @@ int stopStateMachine(){
 
 enum runStatus getRunStatus(){
 #ifdef VIRTUAL
-	if(virtual_status == 0){
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
+	if(virtual_status == 0) {
 		LOG(logINFOBLUE, ("Status: IDLE\n"));
 		return IDLE;
 	}else{
@@ -2191,6 +2241,9 @@ int readFrameFromFifo() {
 
 uint32_t runBusy() {
 #ifdef VIRTUAL
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
     return virtual_status;
 #endif
 	uint32_t s = (bus_r(STATUS_REG) & STATUS_RN_BSY_MSK);
diff --git a/slsDetectorServers/mythen3DetectorServer/CMakeLists.txt b/slsDetectorServers/mythen3DetectorServer/CMakeLists.txt
index f6a4c841c..72bb24351 100644
--- a/slsDetectorServers/mythen3DetectorServer/CMakeLists.txt
+++ b/slsDetectorServers/mythen3DetectorServer/CMakeLists.txt
@@ -10,6 +10,7 @@ add_executable(mythen3DetectorServer_virtual
     ../slsDetectorServer/src/LTC2620_Driver.c
     ../slsDetectorServer/src/ALTERA_PLL_CYCLONE10.c   
     ../slsDetectorServer/src/programFpgaNios.c
+    ../slsDetectorServer/src/communication_virtual.c
 )
 
 include_directories(
diff --git a/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c
index 88f7db52d..f34f6c124 100644
--- a/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c
@@ -8,6 +8,7 @@
 #include "ALTERA_PLL_CYCLONE10.h" 
 #ifdef VIRTUAL
 #include "communication_funcs_UDP.h"
+#include "communication_virtual.h"
 #endif
 
 #include <string.h>
@@ -24,6 +25,7 @@ extern udpStruct udpDetails;
 extern const enum detectorType myDetectorType;
 
 // Global variable from communication_funcs.c
+extern int isControlServer;
 extern void getMacAddressinString(char* cmac, int size, uint64_t mac);
 extern void getIpAddressinString(char* cip, uint32_t ip);
 
@@ -324,6 +326,12 @@ void initStopServer() {
 		LOG(logERROR, ("Stop Server: Map Fail. Dangerous to continue. Goodbye!\n"));
 		exit(EXIT_FAILURE);
 	}
+#ifdef VIRTUAL
+	virtual_stop = 0;
+	if (!isControlServer) {
+		ComVirtual_setStop(virtual_stop);
+	}
+#endif
 }
 
 
@@ -348,6 +356,12 @@ void setupDetector() {
 			dacValues[i] = 0;
 		}
 	}
+#ifdef VIRTUAL
+	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
+#endif
 
 	// pll defines
 	ALTERA_PLL_C10_SetDefines(REG_OFFSET, BASE_READOUT_PLL, BASE_SYSTEM_PLL, PLL_RESET_REG, PLL_RESET_REG, PLL_RESET_READOUT_MSK, PLL_RESET_SYSTEM_MSK, READOUT_PLL_VCO_FREQ_HZ, SYSTEM_PLL_VCO_FREQ_HZ);
@@ -1351,10 +1365,21 @@ int startStateMachine(){
 	LOG(logINFOBLUE, ("Starting State Machine\n"));
 	// set status to running
 	virtual_status = 1;
-	virtual_stop = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+		virtual_stop = ComVirtual_getStop();
+		if (virtual_stop != 0) {
+			LOG(logERROR, ("Cant start acquisition. "
+			"Stop server has not updated stop status to 0\n"));
+			return FAIL;
+		}
+	}
 	if(pthread_create(&pthread_virtual_tid, NULL, &start_timer, NULL)) {
 		LOG(logERROR, ("Could not start Virtual acquisition thread\n"));
 		virtual_status = 0;
+		if (isControlServer) {
+			ComVirtual_setStatus(virtual_status);
+		}	
 		return FAIL;
 	}
 	LOG(logINFOGREEN, ("Virtual Acquisition started\n"));
@@ -1375,6 +1400,10 @@ int startStateMachine(){
 
 #ifdef VIRTUAL
 void* start_timer(void* arg) {
+	if (!isControlServer) {
+		return NULL;
+	}
+
 	int64_t periodNs = getPeriod();
 	int numFrames = (getNumFrames() *
 						getNumTriggers() );
@@ -1401,6 +1430,8 @@ void* start_timer(void* arg) {
 		// loop over number of frames
     	for (frameNr = 0; frameNr != numFrames; ++frameNr) {
 
+			// update the virtual stop from stop server
+			virtual_stop = ComVirtual_getStop();
 			//check if virtual_stop is high
 			if(virtual_stop == 1){
 				break;
@@ -1455,6 +1486,9 @@ void* start_timer(void* arg) {
 	closeUDPSocket(0);
 
 	virtual_status = 0;
+	if (isControlServer) {
+		ComVirtual_setStatus(virtual_status);
+	}
 	LOG(logINFOBLUE, ("Finished Acquiring\n"));
 	return NULL;
 }
@@ -1464,7 +1498,18 @@ void* start_timer(void* arg) {
 int stopStateMachine(){
 	LOG(logINFORED, ("Stopping State Machine\n"));
 #ifdef VIRTUAL
-	virtual_stop = 0;
+	if (!isControlServer) {
+		virtual_stop = 1;
+		ComVirtual_setStop(virtual_stop);
+		// read till status is idle
+		int tempStatus = 1;
+		while(tempStatus == 1) {
+			tempStatus = ComVirtual_getStatus();
+		}
+		virtual_stop = 0;
+		ComVirtual_setStop(virtual_stop);
+		LOG(logINFO, ("Stopped State Machine\n"));
+	}	
 	return OK;
 #endif
 	//stop state machine
@@ -1475,10 +1520,13 @@ int stopStateMachine(){
 
 enum runStatus getRunStatus(){
 #ifdef VIRTUAL
-	if(virtual_status == 0){
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
+	if(virtual_status == 0) {
 		LOG(logINFOBLUE, ("Status: IDLE\n"));
 		return IDLE;
-	}else{
+	} else{
 		LOG(logINFOBLUE, ("Status: RUNNING\n"));
 		return RUNNING;
 	}
@@ -1550,6 +1598,9 @@ void readFrame(int *ret, char *mess) {
 
 u_int32_t runBusy() {
 #ifdef VIRTUAL
+	if (!isControlServer) {
+		virtual_status = ComVirtual_getStatus();
+	}
     return virtual_status;
 #endif
 	u_int32_t s = (bus_r(PAT_STATUS_REG) & PAT_STATUS_RUN_BUSY_MSK);
diff --git a/slsDetectorServers/slsDetectorServer/include/communication_funcs.h b/slsDetectorServers/slsDetectorServer/include/communication_funcs.h
index bfe60c75a..7b465af6a 100755
--- a/slsDetectorServers/slsDetectorServer/include/communication_funcs.h
+++ b/slsDetectorServers/slsDetectorServer/include/communication_funcs.h
@@ -11,6 +11,13 @@ typedef enum{
 	OTHER
 }intType;
 
+// communciate with stop server
+#ifdef VIRTUAL
+#define FILE_STATUS "/tmp/Sls_virtual_server_status_"
+#define FILE_STOP "/tmp/Sls_virtual_server_stop_"
+#define FD_STATUS 0
+#define FD_STOP 1
+#endif
 
 int bindSocket(unsigned short int port_number);
 int acceptConnection(int socketDescriptor);
diff --git a/slsDetectorServers/slsDetectorServer/include/communication_virtual.h b/slsDetectorServers/slsDetectorServer/include/communication_virtual.h
new file mode 100755
index 000000000..06c6558d4
--- /dev/null
+++ b/slsDetectorServers/slsDetectorServer/include/communication_virtual.h
@@ -0,0 +1,14 @@
+#pragma once
+#ifdef VIRTUAL
+// communciate between control and  stop server
+
+int ComVirtual_createFiles(const int port);
+void ComVirtual_setFileNames(const int port);
+void ComVirtual_setStatus(int value);
+int ComVirtual_getStatus();
+void ComVirtual_setStop(int value);
+int ComVirtual_getStop();
+int ComVirtual_writeToFile(int value, const char* fname, const char* serverName);
+int ComVirtual_readFromFile(int* value, const char* fname, const char* serverName);
+
+#endif
diff --git a/slsDetectorServers/slsDetectorServer/src/communication_funcs_UDP.c b/slsDetectorServers/slsDetectorServer/src/communication_funcs_UDP.c
index edc9c7eab..6ebfcac02 100755
--- a/slsDetectorServers/slsDetectorServer/src/communication_funcs_UDP.c
+++ b/slsDetectorServers/slsDetectorServer/src/communication_funcs_UDP.c
@@ -37,7 +37,7 @@ int setUDPDestinationDetails(int index, const char* ip, unsigned short int port)
 	// convert ip to internet address
 	struct addrinfo hints;
 	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = AF_UNSPEC;
+	hints.ai_family = AF_INET;
 	hints.ai_socktype = SOCK_DGRAM;
 	hints.ai_flags = 0;
 	hints.ai_protocol = 0;
@@ -83,19 +83,16 @@ int createUDPSocket(int index) {
 	LOG(logINFO, ("Udp client socket created for server (port %d, ip:%s)\n",
 			udpDestinationPort[index], udpDestinationIp[index]));
 
+	// Using connect expects that the receiver (udp server) exists to listen to these packets
 	// connecting allows to use "send/write" instead of "sendto", avoiding checking for server address for each packet
-	// using write without a connect will end in segv
-	if (connect(udpSockfd[index],udpServerAddrInfo[index]->ai_addr, udpServerAddrInfo[index]->ai_addrlen)==-1) {
-		LOG(logERROR, ("Could not connect to UDP server at ip:%s, port:%d. (Error code:%d, %s)\n",
-				udpDestinationIp[index], udpDestinationPort[index],  errno, gai_strerror(errno)));
-	}
+	// using write without a connect will end in segv 
 	LOG(logINFO, ("Udp client socket connected\n",
 				udpDestinationPort[index], udpDestinationIp[index]));
 	return OK;
 }
 
 int sendUDPPacket(int index, const char* buf, int length) {
-	int n = write(udpSockfd[index], buf, length);
+	int n = sendto(udpSockfd[index], buf, length, 0, udpServerAddrInfo[index]->ai_addr, udpServerAddrInfo[index]->ai_addrlen);
 	// udp sends atomically, no need to handle partial data
 	if (n == -1) {
 		LOG(logERROR, ("Could not send udp packet for socket %d. (Error code:%d, %s)\n",
diff --git a/slsDetectorServers/slsDetectorServer/src/communication_virtual.c b/slsDetectorServers/slsDetectorServer/src/communication_virtual.c
new file mode 100755
index 000000000..cb1cdf5d9
--- /dev/null
+++ b/slsDetectorServers/slsDetectorServer/src/communication_virtual.c
@@ -0,0 +1,120 @@
+#ifdef VIRTUAL
+#include "communication_virtual.h" 
+#include "clogger.h"
+
+#include <string.h>
+#include <unistd.h>     // usleep
+
+#define FILE_STATUS "/tmp/sls_virtual_server_status_"
+#define FILE_STOP "/tmp/sls_virtual_server_stop_"
+#define FD_STATUS 0
+#define FD_STOP 1
+#define FILE_NAME_LENGTH 1000
+
+FILE* fd[2] = {NULL, NULL};
+char fnameStatus[FILE_NAME_LENGTH];
+char fnameStop[FILE_NAME_LENGTH];
+int portNumber = 0;
+
+int ComVirtual_createFiles(const int port) {
+	portNumber = port;
+    // control server writign status file
+	memset(fnameStatus, 0, FILE_NAME_LENGTH);
+	sprintf(fnameStatus, "%s%d", FILE_STATUS, port);
+    FILE* fd = NULL;
+    if (NULL == (fd = fopen(fnameStatus, "w"))) {
+        LOG(logERROR, ("Could not open the file %s for virtual communication\n", 
+		fnameStatus));
+        return 0;
+    }
+	fclose(fd);
+	LOG(logINFOBLUE, ("Created status file %s\n", fnameStatus));
+
+	// stop server writing stop file
+    memset(fnameStop, 0, FILE_NAME_LENGTH);
+	sprintf(fnameStop, "%s%d", FILE_STOP, port);
+    if (NULL == (fd = fopen(fnameStop, "w"))) {
+        LOG(logERROR, ("Could not open the file %s for virtual communication\n", 
+		fnameStop));
+        return 0;
+    }
+	fclose(fd);
+	LOG(logINFOBLUE, ("Created stop file %s\n", fnameStop));
+
+	return 1;
+}
+
+void ComVirtual_setFileNames(const int port) {
+	portNumber = port;
+    memset(fnameStatus, 0, FILE_NAME_LENGTH);
+    memset(fnameStop, 0, FILE_NAME_LENGTH);
+	sprintf(fnameStatus, "%s%d", FILE_STATUS, port);
+	sprintf(fnameStop, "%s%d", FILE_STOP, port);
+}
+
+void ComVirtual_setStatus(int value) {
+	while (!ComVirtual_writeToFile(value, fnameStatus, "Control")) {
+        usleep(100);
+    }
+}
+
+int ComVirtual_getStatus() {
+    int retval = 0;
+	while (!ComVirtual_readFromFile(&retval, fnameStatus, "Stop")) {
+        usleep(100);
+    }
+    return retval;
+}
+
+void ComVirtual_setStop(int value) {
+	while (!ComVirtual_writeToFile(value, fnameStop, "Stop")) {
+        usleep(100);
+    }
+}
+
+int ComVirtual_getStop() {
+    int retval = 0;
+	while (!ComVirtual_readFromFile(&retval, fnameStop, "Control")) {
+        usleep(100);
+    }
+    return retval;
+}
+
+int ComVirtual_writeToFile(int value, const char* fname, const char* serverName) {
+    FILE* fd = NULL;
+    if (NULL == (fd = fopen(fname, "w"))) {
+        LOG(logERROR, ("Vritual %s Server [%d] could not open "
+		"the file %s for writing\n", 
+        serverName, portNumber, fname));
+        return 0;
+    }
+    while (fwrite(&value, sizeof(value), 1, fd) < 1) {
+        LOG(logERROR, ("Vritual %s Server [%d] could not write "
+		"to file %s\n", 
+        serverName, portNumber, fname));
+        return 0;
+    }
+    fclose(fd);
+	return 1;
+}
+
+int ComVirtual_readFromFile(int* value, const char* fname, const char* serverName) {
+    FILE* fd = NULL;
+    if (NULL == (fd = fopen(fname, "r"))) {
+        LOG(logERROR, ("Vritual %s Server [%d] could not open "
+		"the file %s for reading\n", 
+        serverName, portNumber, fname));
+        return 0;
+    }
+    while (fread(value, sizeof(int), 1, fd) < 1) {
+        LOG(logERROR, ("Vritual %s Server [%d] could not read "
+		"from file %s\n", 
+        serverName, portNumber, fname));
+        return 0;
+    }
+    fclose(fd);
+	return 1;
+}
+
+
+#endif
\ No newline at end of file
diff --git a/slsDetectorServers/slsDetectorServer/src/slsDetectorServer.c b/slsDetectorServers/slsDetectorServer/src/slsDetectorServer.c
index 301b0e51b..c324a9f2b 100755
--- a/slsDetectorServers/slsDetectorServer/src/slsDetectorServer.c
+++ b/slsDetectorServers/slsDetectorServer/src/slsDetectorServer.c
@@ -7,6 +7,9 @@
 #include "slsDetectorServer_funcs.h"
 #include "slsDetectorServer_defs.h"
 #include "versionAPI.h"
+#ifdef VIRTUAL
+#include "communication_virtual.h"
+#endif
 
 #include <signal.h>
 #include <string.h>
@@ -31,7 +34,8 @@ void error(char *msg){
 	perror(msg);
 }
 
-int main(int argc, char *argv[]){
+int main(int argc, char *argv[]) {
+
 	// print version
 	if (argc > 1 && !strcasecmp(argv[1], "-version")) {
         int version = 0;
@@ -50,8 +54,9 @@ int main(int argc, char *argv[]){
 	}
 
     int portno = DEFAULT_PORTNO;
-	int retval = OK;
-	int fd = 0;
+	isControlServer = 1;
+	debugflag = 0;
+	checkModuleFlag = 1;
 
 	// if socket crash, ignores SISPIPE, prevents global signal handler
 	// subsequent read/write to socket gives error - must handle locally
@@ -100,16 +105,19 @@ int main(int argc, char *argv[]){
 		}
 	}
 
-#ifdef STOP_SERVER
-	char cmd[MAX_STR_LENGTH];
-	memset(cmd, 0, MAX_STR_LENGTH);
-#endif
+	// control server
 	if (isControlServer) {
-		LOG(logINFO, ("Opening control server on port %d \n", portno));
 #ifdef STOP_SERVER
+		// start stop server process
+		char cmd[MAX_STR_LENGTH];
+		memset(cmd, 0, MAX_STR_LENGTH);
 		{
 			int i;
 			for (i = 0; i < argc; ++i) {
+				if (!strcasecmp(argv[i], "-port")) {
+					i +=2;
+					continue;
+				}
 				if (i > 0) {
 					strcat(cmd, " ");
 				}
@@ -123,31 +131,42 @@ int main(int argc, char *argv[]){
 			LOG(logDEBUG1, ("Command to start stop server:%s\n", cmd));
 			system(cmd);
 		}
+		LOG(logINFOBLUE, ("Control Server [%d]\n", portno));
+#ifdef VIRTUAL
+		// creating files for virtual servers to communicate with each other
+		if (!ComVirtual_createFiles(portno)) { 
+			return -1;
+		}
+#endif
+#endif
+	} 
+	// stop server
+	else {
+		LOG(logINFOBLUE, ("Stop Server [%d]\n", portno));
+#ifdef VIRTUAL
+		ComVirtual_setFileNames(portno - 1);
 #endif
-	} else {
-		LOG(logINFO,("Opening stop server on port %d \n", portno));
 	}
 
+
 	init_detector();
-
-	{	// bind socket
-		sockfd = bindSocket(portno);
-		if (ret == FAIL)
-			return -1;
-	}
-
+	// bind socket
+	sockfd = bindSocket(portno);
+	if (ret == FAIL)
+		return -1;
 	// assign function table
 	function_table();
 
 	if (isControlServer) {
 		LOG(logINFOBLUE, ("Control Server Ready...\n\n"));
 	} else {
-		LOG(logINFO, ("Stop Server Ready...\n\n"));
+		LOG(logINFOBLUE, ("Stop Server Ready...\n\n"));
 	}
 
 	// waits for connection
+	int retval = OK;
 	while(retval != GOODBYE && retval != REBOOT) {
-		fd = acceptConnection(sockfd);
+		int fd = acceptConnection(sockfd);
 		if (fd > 0) {
 			retval = decode_function(fd);
 			closeConnection(fd);
diff --git a/slsDetectorSoftware/tests/test-CmdProxy-global.cpp b/slsDetectorSoftware/tests/test-CmdProxy-global.cpp
index 7ff52aef9..b8de30eea 100644
--- a/slsDetectorSoftware/tests/test-CmdProxy-global.cpp
+++ b/slsDetectorSoftware/tests/test-CmdProxy-global.cpp
@@ -49,7 +49,6 @@ void test_onchip_dac(defs::dacIndex index, const std::string &dacname, int dacva
     auto dacValueStr = sls::ToStringHex(dacvalue);
     auto chipIndexStr = std::to_string(chipIndex);
     std::ostringstream oss_set, oss_get;
-    std::cout << "chipindexstr:"<<chipIndexStr<<" dacvaluestr:"<<dacValueStr<<std::endl;
     proxy.Call(dacname, {chipIndexStr, dacValueStr}, -1, PUT, oss_set);
     REQUIRE(oss_set.str() == dacname + " " + chipIndexStr + " " + dacValueStr + "\n");
     proxy.Call(dacname, {chipIndexStr}, -1, GET, oss_get);
diff --git a/slsDetectorSoftware/tests/test-CmdProxy.cpp b/slsDetectorSoftware/tests/test-CmdProxy.cpp
index 1ddf65ecd..d4785705d 100644
--- a/slsDetectorSoftware/tests/test-CmdProxy.cpp
+++ b/slsDetectorSoftware/tests/test-CmdProxy.cpp
@@ -852,11 +852,118 @@ TEST_CASE("temp_fpga", "[.cmd][.new]") {
     }
 }
 
+/* acquisition */
 
+TEST_CASE("clearbusy", "[.cmd][.new]") {
+    Detector det;
+    CmdProxy proxy(&det);
+    REQUIRE_NOTHROW(proxy.Call("clearbusy", {}, -1, PUT));
+    REQUIRE_THROWS(proxy.Call("clearbusy", {"0"}, -1, PUT));
+    REQUIRE_THROWS(proxy.Call("clearbusy", {}, -1, GET));
+}
 
+TEST_CASE("start", "[.cmd][.new]") {
+    Detector det;
+    CmdProxy proxy(&det);
+    // PUT only command
+    REQUIRE_THROWS(proxy.Call("start", {}, -1, GET));
+    auto prev_val = det.getExptime();
+    det.setExptime(std::chrono::seconds(2));
+    {
+        std::ostringstream oss;
+        proxy.Call("start", {}, -1, PUT, oss);
+        REQUIRE(oss.str() == "start successful\n");
+    }
+    {
+        std::ostringstream oss;
+        proxy.Call("status", {}, -1, GET, oss);
+        REQUIRE(oss.str() == "status running\n");
+    }
+    det.stopDetector();
+    for (int i = 0; i != det.size(); ++i) {
+        det.setExptime(prev_val[i], {i});
+    }
+}
 
+TEST_CASE("stop", "[.cmd][.new]") {
+    Detector det;
+    CmdProxy proxy(&det);
+    // PUT only command
+    REQUIRE_THROWS(proxy.Call("stop", {}, -1, GET));
+    auto prev_val = det.getExptime();
+    det.setExptime(std::chrono::seconds(2));
+    det.startDetector();
+    {
+        std::ostringstream oss;
+        proxy.Call("status", {}, -1, GET, oss);
+        REQUIRE(oss.str() == "status running\n");
+    }
+    {
+        std::ostringstream oss;
+        proxy.Call("stop", {}, -1, PUT, oss);
+        REQUIRE(oss.str() == "stop successful\n");
+    }
+    {
+        std::ostringstream oss;
+        proxy.Call("status", {}, -1, GET, oss);
+        REQUIRE(oss.str() == "status idle\n");
+    }
+    for (int i = 0; i != det.size(); ++i) {
+        det.setExptime(prev_val[i], {i});
+    }
+}
 
+TEST_CASE("status", "[.cmd][.new]") {
+    Detector det;
+    CmdProxy proxy(&det);
+    auto prev_val = det.getExptime();
+    det.setExptime(std::chrono::seconds(2));
+    det.startDetector();
+    {
+        std::ostringstream oss;
+        proxy.Call("status", {}, -1, GET, oss);
+        REQUIRE(oss.str() == "status running\n");
+    }
+    det.stopDetector();
+    {
+        std::ostringstream oss;
+        proxy.Call("status", {}, -1, GET, oss);
+        REQUIRE(oss.str() == "status idle\n");
+    }
+    for (int i = 0; i != det.size(); ++i) {
+        det.setExptime(prev_val[i], {i});
+    } 
+}
 
+TEST_CASE("startingfnum", "[.cmd][.new]") {
+    Detector det;
+    CmdProxy proxy(&det);
+    auto det_type = det.getDetectorType().squash();
+    if (det_type == defs::EIGER || det_type == defs::JUNGFRAU) {
+        auto prev_sfnum = det.getStartingFrameNumber();
+        REQUIRE_THROWS(proxy.Call("startingfnum", {"0"}, -1, PUT));
+        {
+            std::ostringstream oss;
+            proxy.Call("startingfnum", {"3"}, -1, PUT, oss);
+            REQUIRE(oss.str() == "startingfnum 3\n");
+        }
+        {
+            std::ostringstream oss;
+            proxy.Call("startingfnum", {}, -1, GET, oss);
+            REQUIRE(oss.str() == "startingfnum 3\n");
+        }
+        {
+            std::ostringstream oss;
+            proxy.Call("startingfnum", {"1"}, -1, PUT, oss);
+            REQUIRE(oss.str() == "startingfnum 1\n");
+        }
+        for (int i = 0; i != det.size(); ++i) {
+            det.setStartingFrameNumber(prev_sfnum[i], {i});
+        } 
+    } else {
+        REQUIRE_THROWS(proxy.Call("startingfnum", {}, -1, GET));
+    }
+}