diff --git a/slsReceiverSoftware/include/DataStreamer.h b/slsReceiverSoftware/include/DataStreamer.h
index 6db211be5..cd30f68d3 100644
--- a/slsReceiverSoftware/include/DataStreamer.h
+++ b/slsReceiverSoftware/include/DataStreamer.h
@@ -23,8 +23,9 @@ class DataStreamer : private virtual slsReceiverDefs, public ThreadObject {
 	 * @param f address of Fifo pointer
 	 * @param dr pointer to dynamic range
 	 * @param sEnable pointer to short frame enable
+	 * @param fi pointer to file index
 	 */
-	DataStreamer(Fifo*& f, uint32_t* dr, int* sEnable);
+	DataStreamer(Fifo*& f, uint32_t* dr, int* sEnable, uint64_t* fi);
 
 	/**
 	 * Destructor
@@ -198,6 +199,9 @@ class DataStreamer : private virtual slsReceiverDefs, public ThreadObject {
 	/** Pointer to short frame enable */
 	int* shortFrameEnable;
 
+	/** Pointer to file index */
+	uint64_t* fileIndex;
+
 	/** Aquisition Started flag */
 	bool acquisitionStartedFlag;
 
diff --git a/slsReceiverSoftware/include/ZmqSocket.h b/slsReceiverSoftware/include/ZmqSocket.h
index 127528470..37803bc0c 100644
--- a/slsReceiverSoftware/include/ZmqSocket.h
+++ b/slsReceiverSoftware/include/ZmqSocket.h
@@ -246,7 +246,7 @@ public:
 	 * @param dummy true if end of acquistion else false
 	 * @returns 0 if error, else 1
 	 */
-	int SendHeaderData ( int index, bool dummy, uint32_t jsonversion, uint32_t dynamicrange = 0,
+	int SendHeaderData ( int index, bool dummy, uint32_t jsonversion, uint32_t dynamicrange = 0, uint64_t fileIndex = 0,
 			uint32_t npixelsx = 0, uint32_t npixelsy = 0,
 			uint64_t acqIndex = 0, uint64_t fIndex = 0, char* fname = NULL,
 			uint64_t frameNumber = 0, uint32_t expLength = 0, uint32_t packetNumber = 0,
@@ -261,8 +261,9 @@ public:
 		const char* jsonHeaderFormat =
 				"{"
 				"\"jsonversion\":%u, "
-				"\"bitmode\":%d, "
-				"\"shape\":[%d, %d], "
+				"\"bitmode\":%u, "
+				"\"fileIndex\":%llu, "
+				"\"shape\":[%u, %u], "
 				"\"acqIndex\":%llu, "
 				"\"fIndex\":%llu, "
 				"\"fname\":\"%s\", "
@@ -283,7 +284,7 @@ public:
 				"\"version\":%u"
 				"}\n\0";
 		int length = sprintf(buf, jsonHeaderFormat,
-				jsonversion, dynamicrange, npixelsx, npixelsy,
+				jsonversion, dynamicrange, fileIndex, npixelsx, npixelsy,
 				acqIndex, fIndex, (fname == NULL)? "":fname, dummy?0:1,
 						frameNumber, expLength, packetNumber, bunchId, timestamp,
 						modId, xCoord, yCoord, zCoord, debug, roundRNumber,
diff --git a/slsReceiverSoftware/src/DataStreamer.cpp b/slsReceiverSoftware/src/DataStreamer.cpp
index ddc013f1b..a041f4d7c 100644
--- a/slsReceiverSoftware/src/DataStreamer.cpp
+++ b/slsReceiverSoftware/src/DataStreamer.cpp
@@ -26,13 +26,14 @@ pthread_mutex_t DataStreamer::Mutex = PTHREAD_MUTEX_INITIALIZER;
 bool DataStreamer::SilentMode(false);
 
 
-DataStreamer::DataStreamer(Fifo*& f, uint32_t* dr, int* sEnable) :
+DataStreamer::DataStreamer(Fifo*& f, uint32_t* dr, int* sEnable, uint64_t* fi) :
 		ThreadObject(NumberofDataStreamers),
 		generalData(0),
 		fifo(f),
 		zmqSocket(0),
 		dynamicRange(dr),
 		shortFrameEnable(sEnable),
+		fileIndex(fi),
 		acquisitionStartedFlag(false),
 		measurementStartedFlag(false),
 		firstAcquisitionIndex(0),
@@ -270,7 +271,7 @@ int DataStreamer::SendHeader(sls_detector_header* header, bool dummy) {
 	uint64_t frameIndex = header->frameNumber - firstMeasurementIndex;
 	uint64_t acquisitionIndex = header->frameNumber - firstAcquisitionIndex;
 
-	return zmqSocket->SendHeaderData(index, dummy, SLS_DETECTOR_JSON_HEADER_VERSION, *dynamicRange,
+	return zmqSocket->SendHeaderData(index, dummy, SLS_DETECTOR_JSON_HEADER_VERSION, *dynamicRange, *fileIndex,
 			generalData->nPixelsX_Streamer, generalData->nPixelsY_Streamer,
 			acquisitionIndex, frameIndex, fileNametoStream,
 			header->frameNumber, header->expLength, header->packetNumber, header->bunchId, header->timestamp,
diff --git a/slsReceiverSoftware/src/UDPStandardImplementation.cpp b/slsReceiverSoftware/src/UDPStandardImplementation.cpp
index d19dc6141..6e79edc08 100644
--- a/slsReceiverSoftware/src/UDPStandardImplementation.cpp
+++ b/slsReceiverSoftware/src/UDPStandardImplementation.cpp
@@ -209,7 +209,7 @@ int UDPStandardImplementation::setDataStreamEnable(const bool enable) {\
 		if (enable) {
 			bool error = false;
 			for ( int i = 0; i < numThreads; ++i ) {
-				dataStreamer.push_back(new DataStreamer(fifo[i], &dynamicRange, &shortFrameEnable));
+				dataStreamer.push_back(new DataStreamer(fifo[i], &dynamicRange, &shortFrameEnable, &fileIndex));
 				dataStreamer[i]->SetGeneralData(generalData);
 				// check again
 				if (streamingPort == 0)