diff --git a/slsDetectorSoftware/tests/test-CmdProxy-rx.cpp b/slsDetectorSoftware/tests/test-CmdProxy-rx.cpp
index d283a4531..93cd63def 100644
--- a/slsDetectorSoftware/tests/test-CmdProxy-rx.cpp
+++ b/slsDetectorSoftware/tests/test-CmdProxy-rx.cpp
@@ -620,6 +620,30 @@ TEST_CASE("rx_readfreq", "[.cmd][.rx][.new]") {
     }
 }
 
+TEST_CASE("rx_zmqstartfnum", "[.cmd][.rx][.new]") {
+    Detector det;
+    CmdProxy proxy(&det);
+    auto prev_val = det.getRxZmqStartingFrame();
+    {
+        std::ostringstream oss;
+        proxy.Call("rx_zmqstartfnum", {"5"}, -1, PUT, oss);
+        REQUIRE(oss.str() == "rx_zmqstartfnum 5\n");
+    }
+    {
+        std::ostringstream oss;
+        proxy.Call("rx_zmqstartfnum", {}, -1, GET, oss);
+        REQUIRE(oss.str() == "rx_zmqstartfnum 5\n");
+    }
+    {
+        std::ostringstream oss;
+        proxy.Call("rx_zmqstartfnum", {"0"}, -1, PUT, oss);
+        REQUIRE(oss.str() == "rx_zmqstartfnum 0\n");
+    }
+    for (int i = 0; i != det.size(); ++i) {
+        det.setRxZmqStartingFrame(prev_val[i], {i});
+    }
+}
+
 TEST_CASE("rx_zmqport", "[.cmd][.rx][.new]") {
     Detector det;
     CmdProxy proxy(&det);
diff --git a/slsReceiverSoftware/src/DataProcessor.cpp b/slsReceiverSoftware/src/DataProcessor.cpp
index be6df647a..e15243136 100644
--- a/slsReceiverSoftware/src/DataProcessor.cpp
+++ b/slsReceiverSoftware/src/DataProcessor.cpp
@@ -24,17 +24,17 @@ const std::string DataProcessor::TypeName = "DataProcessor";
 DataProcessor::DataProcessor(int ind, detectorType dtype, Fifo *f,
                              fileFormat *ftype, bool fwenable, bool *mfwenable,
                              bool *dsEnable, uint32_t *dr, uint32_t *freq,
-                             uint32_t *timer, uint32_t *sfnum, bool *fp, bool *act,
-                             bool *depaden, bool *sm, bool *qe,
+                             uint32_t *timer, uint32_t *sfnum, bool *fp,
+                             bool *act, bool *depaden, bool *sm, bool *qe,
                              std::vector<int> *cdl, int *cdo, int *cad)
     : ThreadObject(ind, TypeName), fifo(f), myDetectorType(dtype),
       dataStreamEnable(dsEnable), fileFormatType(ftype),
       fileWriteEnable(fwenable), masterFileWriteEnable(mfwenable),
       dynamicRange(dr), streamingFrequency(freq), streamingTimerInMs(timer),
-      streamingStartFnum(sfnum),
-      activated(act), deactivatedPaddingEnable(depaden), silentMode(sm),
-      quadEnable(qe), framePadding(fp), ctbDbitList(cdl), ctbDbitOffset(cdo),
-      ctbAnalogDataBytes(cad) {
+      streamingStartFnum(sfnum), activated(act),
+      deactivatedPaddingEnable(depaden), silentMode(sm), quadEnable(qe),
+      framePadding(fp), ctbDbitList(cdl), ctbDbitOffset(cdo),
+      ctbAnalogDataBytes(cad), firstStreamerFrame(false) {
     LOG(logDEBUG) << "DataProcessor " << ind << " created";
     memset((void *)&timerBegin, 0, sizeof(timespec));
 }
@@ -61,6 +61,7 @@ void DataProcessor::ResetParametersforNewAcquisition() {
     numFramesCaught = 0;
     firstIndex = 0;
     currentFrameIndex = 0;
+    firstStreamerFrame = true;
 }
 
 void DataProcessor::RecordFirstIndex(uint64_t fnum) {
@@ -183,13 +184,21 @@ void DataProcessor::ThreadExecution() {
         return;
     }
 
-    ProcessAnImage(buffer);
+    uint64_t fnum = ProcessAnImage(buffer);
 
     // stream (if time/freq to stream) or free
-    if (*dataStreamEnable && SendToStreamer())
+    if (*dataStreamEnable && SendToStreamer()) {
+        // if first frame to stream, add frame index to fifo header (might not
+        // be the first)
+        if (firstStreamerFrame) {
+            firstStreamerFrame = false;
+            (*((uint32_t *)(buffer + FIFO_DATASIZE_NUMBYTES))) =
+                (uint32_t)(fnum - firstIndex);
+        }
         fifo->PushAddressToStream(buffer);
-    else
+    } else {
         fifo->FreeAddress(buffer);
+    }
 }
 
 void DataProcessor::StopProcessing(char *buf) {
@@ -207,7 +216,7 @@ void DataProcessor::StopProcessing(char *buf) {
     LOG(logDEBUG1) << index << ": Processing Completed";
 }
 
-void DataProcessor::ProcessAnImage(char *buf) {
+uint64_t DataProcessor::ProcessAnImage(char *buf) {
 
     auto *rheader = (sls_receiver_header *)(buf + FIFO_HEADER_NUMBYTES);
     sls_detector_header header = rheader->detHeader;
@@ -222,7 +231,6 @@ void DataProcessor::ProcessAnImage(char *buf) {
 
     if (!startedFlag) {
         RecordFirstIndex(fnum);
-
         if (*dataStreamEnable) {
             // restart timer
             clock_gettime(CLOCK_REALTIME, &timerBegin);
@@ -279,6 +287,7 @@ void DataProcessor::ProcessAnImage(char *buf) {
               // stopReceiver tcp)
         }
     }
+    return fnum;
 }
 
 bool DataProcessor::SendToStreamer() {
diff --git a/slsReceiverSoftware/src/DataProcessor.h b/slsReceiverSoftware/src/DataProcessor.h
index 28a65a970..26917a947 100644
--- a/slsReceiverSoftware/src/DataProcessor.h
+++ b/slsReceiverSoftware/src/DataProcessor.h
@@ -49,10 +49,9 @@ class DataProcessor : private virtual slsDetectorDefs, public ThreadObject {
      */
     DataProcessor(int ind, detectorType dtype, Fifo *f, fileFormat *ftype,
                   bool fwenable, bool *mfwenable, bool *dsEnable, uint32_t *dr,
-                  uint32_t *freq, uint32_t *timer, 
-                  uint32_t *sfnum, bool *fp, bool *act,
-                  bool *depaden, bool *sm, bool *qe, std::vector<int> *cdl,
-                  int *cdo, int *cad);
+                  uint32_t *freq, uint32_t *timer, uint32_t *sfnum, bool *fp,
+                  bool *act, bool *depaden, bool *sm, bool *qe,
+                  std::vector<int> *cdl, int *cdo, int *cad);
 
     /**
      * Destructor
@@ -203,8 +202,9 @@ class DataProcessor : private virtual slsDetectorDefs, public ThreadObject {
      * Process an image popped from fifo,
      * write to file if fw enabled & update parameters
      * @param buf address of pointer
+     * @returns frame number
      */
-    void ProcessAnImage(char *buf);
+    uint64_t ProcessAnImage(char *buf);
 
     /**
      * Calls CheckTimer and CheckCount for streaming frequency and timer
@@ -324,6 +324,9 @@ class DataProcessor : private virtual slsDetectorDefs, public ThreadObject {
     /** Frame Number of latest processed frame number */
     std::atomic<uint64_t> currentFrameIndex{0};
 
+    /** first streamer frame to add frame index in fifo header */
+    bool firstStreamerFrame{false};
+
     // call back
     /**
      * Call back for raw data
diff --git a/slsReceiverSoftware/src/DataStreamer.cpp b/slsReceiverSoftware/src/DataStreamer.cpp
index 3b06dcd46..9c55803a7 100644
--- a/slsReceiverSoftware/src/DataStreamer.cpp
+++ b/slsReceiverSoftware/src/DataStreamer.cpp
@@ -48,11 +48,14 @@ void DataStreamer::ResetParametersforNewAcquisition(const std::string &fname) {
     }
 }
 
-void DataStreamer::RecordFirstIndex(uint64_t fnum) {
+void DataStreamer::RecordFirstIndex(uint64_t fnum, char *buf) {
     startedFlag = true;
-    firstIndex = fnum;
+    // streamer first index needn't be
+    uint64_t firstVal = fnum - (*((uint32_t *)(buf + FIFO_DATASIZE_NUMBYTES)));
 
-    LOG(logDEBUG1) << index << " First Index: " << firstIndex;
+    firstIndex = firstVal;
+    LOG(logDEBUG1) << index << " First Index: " << firstIndex
+                   << ", First Streamer Index:" << fnum;
 }
 
 void DataStreamer::SetGeneralData(GeneralData *g) { generalData = g; }
@@ -137,7 +140,7 @@ void DataStreamer::ProcessAnImage(char *buf) {
     LOG(logDEBUG1) << "DataStreamer " << index << ": fnum:" << fnum;
 
     if (!startedFlag) {
-        RecordFirstIndex(fnum);
+        RecordFirstIndex(fnum, buf);
     }
 
     // shortframe gotthard
diff --git a/slsReceiverSoftware/src/DataStreamer.h b/slsReceiverSoftware/src/DataStreamer.h
index 6ad4faf80..bbfc5aba9 100644
--- a/slsReceiverSoftware/src/DataStreamer.h
+++ b/slsReceiverSoftware/src/DataStreamer.h
@@ -101,9 +101,10 @@ class DataStreamer : private virtual slsDetectorDefs, public ThreadObject {
   private:
     /**
      * Record First Index
-     * @param fnum frame index to record
+     * @param fnum current frame number
+     * @param buf get frame index from buffer to calculate first index to record
      */
-    void RecordFirstIndex(uint64_t fnum);
+    void RecordFirstIndex(uint64_t fnum, char *buf);
 
     /**
      * Thread Exeution for DataStreamer Class