diff --git a/slsDetectorServers/mythen3DetectorServer/RegisterDefs.h b/slsDetectorServers/mythen3DetectorServer/RegisterDefs.h
index 184485b8e..da52bdc9b 100644
--- a/slsDetectorServers/mythen3DetectorServer/RegisterDefs.h
+++ b/slsDetectorServers/mythen3DetectorServer/RegisterDefs.h
@@ -152,6 +152,17 @@
 #define PKT_CONFIG_1G_INTERFACE_OFST    (16)
 #define PKT_CONFIG_1G_INTERFACE_MSK     (0x00000001 << PKT_CONFIG_1G_INTERFACE_OFST)
 
+#define PKT_FRAG_REG                    (0x01 * REG_OFFSET + BASE_PKT)
+
+#define PKT_FRAG_1G_N_DSR_PER_PKT_OFST  (0)
+#define PKT_FRAG_1G_N_DSR_PER_PKT_MSK   (0x0000003F << PKT_FRAG_1G_N_DSR_PER_PKT_OFST)
+#define PKT_FRAG_10G_N_DSR_PER_PKT_OFST (8)
+#define PKT_FRAG_10G_N_DSR_PER_PKT_MSK  (0x0000003F << PKT_FRAG_10G_N_DSR_PER_PKT_OFST)
+#define PKT_FRAG_1G_NUM_PACKETS_OFST    (16)
+#define PKT_FRAG_1G_NUM_PACKETS_MSK     (0x0000003F << PKT_FRAG_1G_NUM_PACKETS_OFST)
+#define PKT_FRAG_10G_NUM_PACKETS_OFST   (24)
+#define PKT_FRAG_10G_NUM_PACKETS_MSK    (0x0000003F << PKT_FRAG_10G_NUM_PACKETS_OFST)
+
 /* Module Coordinates Register */
 #define COORD_0_REG                     (0x02 * REG_OFFSET + BASE_PKT)
 #define COORD_ROW_OFST                  (0)
diff --git a/slsDetectorServers/mythen3DetectorServer/bin/mythen3DetectorServer_developer b/slsDetectorServers/mythen3DetectorServer/bin/mythen3DetectorServer_developer
index d840f9de0..ed0eb5fa3 100755
Binary files a/slsDetectorServers/mythen3DetectorServer/bin/mythen3DetectorServer_developer and b/slsDetectorServers/mythen3DetectorServer/bin/mythen3DetectorServer_developer differ
diff --git a/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c b/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c
index cc80aa5fd..f606611ad 100644
--- a/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c
@@ -409,6 +409,9 @@ void setupDetector() {
     setDefaultDacs();
     setASICDefaults();
 
+    // no roi for 1g and 10g
+    setumberOfDeserializers(MAX_NUM_DESERIALIZERS, 0);
+    setumberOfDeserializers(MAX_NUM_DESERIALIZERS, 1);
     // dynamic range
     setDynamicRange(DEFAULT_DYNAMIC_RANGE);
     // enable all counters
@@ -552,6 +555,7 @@ int setDynamicRange(int dr) {
         // set it
         bus_w(CONFIG_REG, bus_r(CONFIG_REG) & ~CONFIG_DYNAMIC_RANGE_MSK);
         bus_w(CONFIG_REG, bus_r(CONFIG_REG) | regval);
+        updateNumberOfPackets();
     }
 
     uint32_t regval = bus_r(CONFIG_REG) & CONFIG_DYNAMIC_RANGE_MSK;
@@ -1032,6 +1036,7 @@ void setCounterMask(uint32_t arg) {
                                CONFIG_COUNTERS_ENA_MSK));
     LOG(logDEBUG, ("Config Reg: 0x%x\n", bus_r(addr)));
 
+    updateNumberOfPackets();
     updateGatePeriod();
 }
 
@@ -1039,6 +1044,59 @@ uint32_t getCounterMask() {
     return ((bus_r(CONFIG_REG) & CONFIG_COUNTERS_ENA_MSK) >>
             CONFIG_COUNTERS_ENA_OFST);
 }
+void setumberOfDeserializers(int val, int tgEnable) {
+    const uint32_t addr = PKT_FRAG_REG;
+    LOG(logINFO, ("Setting Number of deserializers per packet: %d for %s\n",
+                  val, (tgEnable ? "10g" : "1g")));
+    if (tgEnable) {
+        bus_w(addr, bus_r(addr) & ~PKT_FRAG_10G_N_DSR_PER_PKT_MSK);
+        bus_w(addr, bus_r(addr) | ((val << PKT_FRAG_10G_N_DSR_PER_PKT_OFST) &
+                                   PKT_FRAG_10G_N_DSR_PER_PKT_MSK));
+    } else {
+        bus_w(addr, bus_r(addr) & ~PKT_FRAG_1G_N_DSR_PER_PKT_MSK);
+        bus_w(addr, bus_r(addr) | ((val << PKT_FRAG_1G_N_DSR_PER_PKT_OFST) &
+                                   PKT_FRAG_1G_N_DSR_PER_PKT_MSK));
+    }
+}
+
+void updateNumberOfPackets() {
+    const int ncounters = __builtin_popcount(getCounterMask());
+    const int tgEnable = enableTenGigabitEthernet(-1);
+    int packetsPerFrame = 0;
+
+    // 10g
+    if (tgEnable) {
+        const int dr = setDynamicRange(-1);
+        packetsPerFrame = 1;
+        if (dr == 32 && ncounters > 1) {
+            packetsPerFrame = 2;
+        }
+    }
+    // 1g
+    else {
+        int dataSize = 1280;
+        if (ncounters == 3) {
+            dataSize = 768;
+        }
+        packetsPerFrame = calculateDataBytes() / dataSize;
+    }
+
+    // bus_w()
+    LOG(logINFO, ("Number of Packets/Frame: %d for %s\n", packetsPerFrame,
+                  (tgEnable ? "10g" : "1g")));
+    const uint32_t addr = PKT_FRAG_REG;
+    if (tgEnable) {
+        bus_w(addr, bus_r(addr) & ~PKT_FRAG_10G_NUM_PACKETS_MSK);
+        bus_w(addr, bus_r(addr) |
+                        ((packetsPerFrame << PKT_FRAG_10G_NUM_PACKETS_OFST) &
+                         PKT_FRAG_10G_NUM_PACKETS_MSK));
+    } else {
+        bus_w(addr, bus_r(addr) & ~PKT_FRAG_1G_NUM_PACKETS_MSK);
+        bus_w(addr,
+              bus_r(addr) | ((packetsPerFrame << PKT_FRAG_1G_NUM_PACKETS_OFST) &
+                             PKT_FRAG_1G_NUM_PACKETS_MSK));
+    }
+}
 
 int setDelayAfterTrigger(int64_t val) {
     if (val < 0) {
@@ -1509,6 +1567,7 @@ int enableTenGigabitEthernet(int val) {
         else {
             bus_w(addr, bus_r(addr) & (~PKT_CONFIG_1G_INTERFACE_MSK));
         }
+        updateNumberOfPackets();
     }
     int oneG = ((bus_r(addr) & PKT_CONFIG_1G_INTERFACE_MSK) >>
                 PKT_CONFIG_1G_INTERFACE_OFST);
@@ -2059,24 +2118,38 @@ void *start_timer(void *arg) {
     const int numFrames = (getNumFrames() * getNumTriggers());
     const int64_t expUs = getGatePeriod() / 1000;
 
-    const int imagesize = calculateDataBytes();
+    const int imageSize = calculateDataBytes();
     const int tgEnable = enableTenGigabitEthernet(-1);
-    const int packetsPerFrame =
-        tgEnable ? PACKETS_PER_FRAME_10G : PACKETS_PER_FRAME_1G;
-    const int dataSize = imagesize / packetsPerFrame;
+    const int dr = setDynamicRange(-1);
+    int ncounters = __builtin_popcount(getCounterMask());
+    int dataSize = 0;
+    int packetsPerFrame = 0;
+    // 10g
+    if (tgEnable) {
+        packetsPerFrame = 1;
+        if (dr == 32 && ncounters > 1) {
+            packetsPerFrame = 2;
+        }
+    }
+    // 1g
+    else {
+        dataSize = 1280;
+        if (ncounters == 3) {
+            dataSize = 768;
+        }
+        packetsPerFrame = imageSize / dataSize;
+    }
     const int packetSize = dataSize + sizeof(sls_detector_header);
 
     LOG(logDEBUG1,
-        ("imagesize:%d tg:%d packets/Frame:%d datasize:%d packetSize:%d\n",
-         imagesize, tgEnable, packetsPerFrame, dataSize, packetSize));
+        ("imageSize:%d tg:%d packets/Frame:%d datasize:%d packetSize:%d\n",
+         imageSize, tgEnable, packetsPerFrame, dataSize, packetSize));
 
     // Generate data
-    char imageData[imagesize];
-    memset(imageData, 0, imagesize);
+    char imageData[imageSize];
+    memset(imageData, 0, imageSize);
     {
-        const int dr = setDynamicRange(-1);
-        const int numCounters = __builtin_popcount(getCounterMask());
-        const int nchannels = NCHAN_1_COUNTER * NCHIP * numCounters;
+        const int nchannels = NCHAN_1_COUNTER * NCHIP * ncounters;
 
         switch (dr) {
         /*case 1: // TODO: Not implemented in firmware yet
diff --git a/slsDetectorServers/mythen3DetectorServer/slsDetectorServer_defs.h b/slsDetectorServers/mythen3DetectorServer/slsDetectorServer_defs.h
index 7b5529140..7ba583474 100644
--- a/slsDetectorServers/mythen3DetectorServer/slsDetectorServer_defs.h
+++ b/slsDetectorServers/mythen3DetectorServer/slsDetectorServer_defs.h
@@ -49,6 +49,7 @@
 #define FIXED_PLL_FREQUENCY     (020000000)  // 20MHz
 #define READOUT_PLL_VCO_FREQ_HZ (1250000000) // 1.25GHz
 #define SYSTEM_PLL_VCO_FREQ_HZ  (1000000000) // 1GHz
+#define MAX_NUM_DESERIALIZERS   (40)
 
 /** Other Definitions */
 #define BIT16_MASK         (0xFFFF)
diff --git a/slsDetectorServers/slsDetectorServer/include/slsDetectorFunctionList.h b/slsDetectorServers/slsDetectorServer/include/slsDetectorFunctionList.h
index e38c5f486..c552b24a2 100644
--- a/slsDetectorServers/slsDetectorServer/include/slsDetectorFunctionList.h
+++ b/slsDetectorServers/slsDetectorServer/include/slsDetectorFunctionList.h
@@ -250,6 +250,8 @@ int getNumDigitalSamples();
 #ifdef MYTHEN3D
 void setCounterMask(uint32_t arg);
 uint32_t getCounterMask();
+void setumberOfDeserializers(int val, int tgEnable);
+void updateNumberOfPackets();
 #endif
 
 #if defined(JUNGFRAUD) || defined(GOTTHARDD) || defined(CHIPTESTBOARDD) ||     \
diff --git a/slsDetectorSoftware/src/Module.cpp b/slsDetectorSoftware/src/Module.cpp
index d2dd694c2..353d9ad35 100644
--- a/slsDetectorSoftware/src/Module.cpp
+++ b/slsDetectorSoftware/src/Module.cpp
@@ -1723,9 +1723,8 @@ void Module::setCounterMask(uint32_t countermask) {
     LOG(logDEBUG1) << "Setting Counter mask to " << countermask;
     sendToDetector(F_SET_COUNTER_MASK, countermask, nullptr);
     if (shm()->useReceiverFlag) {
-        int ncounters = __builtin_popcount(countermask);
-        LOG(logDEBUG1) << "Sending Reciver #counters: " << ncounters;
-        sendToReceiver(F_RECEIVER_SET_NUM_COUNTERS, ncounters, nullptr);
+        LOG(logDEBUG1) << "Sending Reciver counter mask: " << countermask;
+        sendToReceiver(F_RECEIVER_SET_COUNTER_MASK, countermask, nullptr);
     }
 }
 
diff --git a/slsReceiverSoftware/src/ClientInterface.cpp b/slsReceiverSoftware/src/ClientInterface.cpp
index 185c63b40..305c334c7 100644
--- a/slsReceiverSoftware/src/ClientInterface.cpp
+++ b/slsReceiverSoftware/src/ClientInterface.cpp
@@ -190,7 +190,7 @@ int ClientInterface::functionTable(){
 	flist[F_SET_RECEIVER_UDP_PORT2]         =   &ClientInterface::set_udp_port2;
 	flist[F_SET_RECEIVER_NUM_INTERFACES]    =   &ClientInterface::set_num_interfaces;
 	flist[F_RECEIVER_SET_ADC_MASK_10G]		=	&ClientInterface::set_adc_mask_10g;
-    flist[F_RECEIVER_SET_NUM_COUNTERS]      =   &ClientInterface::set_num_counters;
+    flist[F_RECEIVER_SET_COUNTER_MASK]      =   &ClientInterface::set_counter_mask;
     flist[F_INCREMENT_FILE_INDEX]           =   &ClientInterface::increment_file_index;
     flist[F_SET_ADDITIONAL_JSON_PARAMETER]  =   &ClientInterface::set_additional_json_parameter;
 	flist[F_GET_ADDITIONAL_JSON_PARAMETER]  =   &ClientInterface::get_additional_json_parameter;
@@ -445,8 +445,7 @@ int ClientInterface::setup_receiver(Interface &socket) {
         }
     }
     if (myDetectorType == MYTHEN3) {
-        int ncounters = __builtin_popcount(arg.countermask);
-        impl()->setNumberofCounters(ncounters);
+        impl()->setCounterMask(arg.countermask);
         impl()->setAcquisitionTime1(arg.expTime1Ns);
         impl()->setAcquisitionTime2(arg.expTime2Ns);
         impl()->setAcquisitionTime3(arg.expTime3Ns);
@@ -1604,11 +1603,11 @@ int ClientInterface::set_adc_mask_10g(Interface &socket) {
     return socket.sendResult(retval);
 }
 
-int ClientInterface::set_num_counters(Interface &socket) {
-    auto arg = socket.Receive<int>();
+int ClientInterface::set_counter_mask(Interface &socket) {
+    auto arg = socket.Receive<uint32_t>();
     verifyIdle(socket);
     LOG(logDEBUG1) << "Setting counters: " << arg;
-    impl()->setNumberofCounters(arg);
+    impl()->setCounterMask(arg);
     return socket.Send(OK);
 }
 
diff --git a/slsReceiverSoftware/src/ClientInterface.h b/slsReceiverSoftware/src/ClientInterface.h
index f008a3672..bf066acb5 100644
--- a/slsReceiverSoftware/src/ClientInterface.h
+++ b/slsReceiverSoftware/src/ClientInterface.h
@@ -146,7 +146,7 @@ class ClientInterface : private virtual slsDetectorDefs {
     int set_udp_port2(sls::ServerInterface &socket);
     int set_num_interfaces(sls::ServerInterface &socket);
     int set_adc_mask_10g(sls::ServerInterface &socket);
-    int set_num_counters(sls::ServerInterface &socket);
+    int set_counter_mask(sls::ServerInterface &socket);
     int increment_file_index(sls::ServerInterface &socket);
     int set_additional_json_parameter(sls::ServerInterface &socket);
     int get_additional_json_parameter(sls::ServerInterface &socket);
diff --git a/slsReceiverSoftware/src/GeneralData.h b/slsReceiverSoftware/src/GeneralData.h
index 90e126cc9..75399f7f1 100644
--- a/slsReceiverSoftware/src/GeneralData.h
+++ b/slsReceiverSoftware/src/GeneralData.h
@@ -157,8 +157,9 @@ class GeneralData {
      * set number of counters (mythen3)
      * @param n number of counters
      * @param dr dynamic range
+     * @param tgEnable ten giga enable
      */
-    virtual void SetNumberofCounters(const int n, const int dr) {
+    virtual void SetNumberofCounters(const int n, const int dr, bool tgEnable) {
         LOG(logERROR) << "SetNumberofCounters is a generic function that "
                          "should be overloaded by a derived class";
     }
@@ -440,17 +441,33 @@ class Mythen3Data : public GeneralData {
      * set number of counters (mythen3)
      * @param n number of counters
      * @param dr dynamic range
+     * @param tgEnable ten giga enable
      */
-    virtual void SetNumberofCounters(const int n, const int dr) {
-        if (n < 1 || n > 3) {
-            throw sls::RuntimeError("Invalid number of counters " +
-                                    std::to_string(n));
-        }
+    virtual void SetNumberofCounters(const int n, const int dr, bool tgEnable) {
         ncounters = n;
         nPixelsX = NCHAN * ncounters;
         LOG(logINFO) << "nPixelsX: " << nPixelsX;
         imageSize = nPixelsX * nPixelsY * ((double)dr / 8.00);
-        dataSize = imageSize / packetsPerFrame;
+        // 10g
+        if (tgEnable) {
+            if (dr == 32 && n > 1) {
+                packetsPerFrame = 2;
+            } else {
+                packetsPerFrame = 1;
+            }
+            dataSize = imageSize / packetsPerFrame;
+        }
+        // 1g
+        else {
+            if (n == 3) {
+                dataSize = 768;
+            } else {
+                dataSize = 1280;
+            }
+            packetsPerFrame = imageSize / dataSize;
+        }
+
+        LOG(logINFO) << "Packets Per Frame: " << packetsPerFrame;
         packetSize = headerSizeinPacket + dataSize;
         LOG(logINFO) << "PacketSize: " << packetSize;
     }
@@ -462,6 +479,7 @@ class Mythen3Data : public GeneralData {
      */
     void SetDynamicRange(int dr, bool tgEnable) {
         imageSize = nPixelsX * nPixelsY * ((double)dr / 8.00);
+
         packetsPerFrame = tgEnable ? 2 : 20;
         dataSize = imageSize / packetsPerFrame;
         packetSize = headerSizeinPacket + dataSize;
diff --git a/slsReceiverSoftware/src/Implementation.cpp b/slsReceiverSoftware/src/Implementation.cpp
index 0e4ea412d..3f8f74077 100644
--- a/slsReceiverSoftware/src/Implementation.cpp
+++ b/slsReceiverSoftware/src/Implementation.cpp
@@ -120,7 +120,7 @@ void Implementation::InitializeMembers() {
     subPeriod = 0;
     numberOfAnalogSamples = 0;
     numberOfDigitalSamples = 0;
-    numberOfCounters = 0;
+    counterMask = 0;
     dynamicRange = 16;
     roi.xmin = -1;
     roi.xmax = -1;
@@ -962,6 +962,7 @@ void Implementation::SetupWriter() {
         masterAttributes->dbitlist |= (1 << i);
     }
     masterAttributes->roi = roi;
+    masterAttributes->counterMask = counterMask;
     masterAttributes->exptime1 = std::chrono::nanoseconds(acquisitionTime1);
     masterAttributes->exptime2 = std::chrono::nanoseconds(acquisitionTime2);
     masterAttributes->exptime3 = std::chrono::nanoseconds(acquisitionTime3);
@@ -1616,24 +1617,30 @@ void Implementation::setNumberofDigitalSamples(const uint32_t i) {
     LOG(logINFO) << "Packets per Frame: " << (generalData->packetsPerFrame);
 }
 
-int Implementation::getNumberofCounters() const {
+uint32_t Implementation::getCounterMask() const {
     LOG(logDEBUG3) << __SHORT_AT__ << " called";
-    return numberOfCounters;
+    return counterMask;
 }
 
-void Implementation::setNumberofCounters(const int i) {
-    if (numberOfCounters != i) {
-        numberOfCounters = i;
-
-        if (myDetectorType == MYTHEN3) {
-            generalData->SetNumberofCounters(i, dynamicRange);
-            // to update npixelsx, npixelsy in file writer
-            for (const auto &it : dataProcessor)
-                it->SetPixelDimension();
-            SetupFifoStructure();
+void Implementation::setCounterMask(const uint32_t i) {
+    if (counterMask != i) {
+        int ncounters = __builtin_popcount(i);
+        if (ncounters < 1 || ncounters > 3) {
+            throw sls::RuntimeError("Invalid number of counters " +
+                                    std::to_string(ncounters) +
+                                    ". Expected 1-3.");
         }
+        counterMask = i;
+        generalData->SetNumberofCounters(ncounters, dynamicRange,
+                                         tengigaEnable);
+        // to update npixelsx, npixelsy in file writer
+        for (const auto &it : dataProcessor)
+            it->SetPixelDimension();
+        SetupFifoStructure();
     }
-    LOG(logINFO) << "Number of Counters: " << numberOfCounters;
+    LOG(logINFO) << "Counter mask: " << sls::ToStringHex(counterMask);
+    int ncounters = __builtin_popcount(counterMask);
+    LOG(logINFO) << "Number of counters: " << ncounters;
 }
 
 uint32_t Implementation::getDynamicRange() const {
@@ -1647,7 +1654,14 @@ void Implementation::setDynamicRange(const uint32_t i) {
         dynamicRange = i;
 
         if (myDetectorType == EIGER || myDetectorType == MYTHEN3) {
-            generalData->SetDynamicRange(i, tengigaEnable);
+
+            if (myDetectorType == EIGER) {
+                generalData->SetDynamicRange(i, tengigaEnable);
+            } else {
+                int ncounters = __builtin_popcount(counterMask);
+                generalData->SetNumberofCounters(ncounters, i, tengigaEnable);
+            }
+
             // to update npixelsx, npixelsy in file writer
             for (const auto &it : dataProcessor)
                 it->SetPixelDimension();
@@ -1689,13 +1703,14 @@ bool Implementation::getTenGigaEnable() const {
 void Implementation::setTenGigaEnable(const bool b) {
     if (tengigaEnable != b) {
         tengigaEnable = b;
+        int ncounters = __builtin_popcount(counterMask);
         // side effects
         switch (myDetectorType) {
         case EIGER:
             generalData->SetTenGigaEnable(b, dynamicRange);
             break;
         case MYTHEN3:
-            generalData->SetDynamicRange(dynamicRange, b);
+            generalData->SetNumberofCounters(ncounters, dynamicRange, b);
             break;
         case MOENCH:
         case CHIPTESTBOARD:
diff --git a/slsReceiverSoftware/src/Implementation.h b/slsReceiverSoftware/src/Implementation.h
index a669a0820..629732001 100644
--- a/slsReceiverSoftware/src/Implementation.h
+++ b/slsReceiverSoftware/src/Implementation.h
@@ -186,8 +186,9 @@ class Implementation : private virtual slsDetectorDefs {
     uint32_t getNumberofDigitalSamples() const;
     /**[Ctb] */
     void setNumberofDigitalSamples(const uint32_t i);
-    int getNumberofCounters() const;
-    void setNumberofCounters(const int i);
+    uint32_t getCounterMask() const;
+    /** [Mythen3] */
+    void setCounterMask(const uint32_t i);
     uint32_t getDynamicRange() const;
     void setDynamicRange(const uint32_t i);
     ROI getROI() const;
@@ -329,7 +330,7 @@ class Implementation : private virtual slsDetectorDefs {
     uint64_t subPeriod;
     uint64_t numberOfAnalogSamples;
     uint64_t numberOfDigitalSamples;
-    int numberOfCounters;
+    uint32_t counterMask;
     uint32_t dynamicRange;
     ROI roi;
     bool tengigaEnable;
diff --git a/slsReceiverSoftware/src/MasterAttributes.h b/slsReceiverSoftware/src/MasterAttributes.h
index de837efcd..0726c29ee 100644
--- a/slsReceiverSoftware/src/MasterAttributes.h
+++ b/slsReceiverSoftware/src/MasterAttributes.h
@@ -40,6 +40,7 @@ struct MasterAttributes {
     uint32_t dbitoffset{0};
     uint64_t dbitlist{0};
     slsDetectorDefs::ROI roi{};
+    uint32_t counterMask{0};
     ns exptime1{0};
     ns exptime2{0};
     ns exptime3{0};
@@ -344,7 +345,7 @@ class EigerMasterAttributes : public MasterAttributes {
         // Rate corrections
         {
             DataSpace dataspace = DataSpace(H5S_SCALAR);
-            StrType strdatatype(PredType::C_S1, 256);
+            StrType strdatatype(PredType::C_S1, 1024);
             DataSet dataset = group->createDataSet("rate corrections",
                                                    strdatatype, dataspace);
             dataset.write(sls::ToString(ratecorr), strdatatype);
@@ -363,6 +364,8 @@ class Mythen3MasterAttributes : public MasterAttributes {
             << "Dynamic Range              : " << dynamicRange << '\n'
             << "Ten Giga                   : " << tenGiga << '\n'
             << "Period                     : " << sls::ToString(period) << '\n'
+            << "Counter Mask               : " << sls::ToStringHex(counterMask)
+            << '\n'
             << "Exptime1                   : " << sls::ToString(exptime1)
             << '\n'
             << "Exptime2                   : " << sls::ToString(exptime2)
@@ -386,6 +389,13 @@ class Mythen3MasterAttributes : public MasterAttributes {
         MasterAttributes::WriteHDF5DynamicRange(fd, group);
         MasterAttributes::WriteHDF5TenGiga(fd, group);
         MasterAttributes::WriteHDF5Period(fd, group);
+        // Counter Mask
+        {
+            DataSpace dataspace = DataSpace(H5S_SCALAR);
+            DataSet dataset = group->createDataSet(
+                "counter mask", PredType::STD_U32LE, dataspace);
+            dataset.write(&counterMask, PredType::STD_U32LE);
+        }
         // Exptime1
         {
             DataSpace dataspace = DataSpace(H5S_SCALAR);
@@ -439,7 +449,7 @@ class Mythen3MasterAttributes : public MasterAttributes {
             DataSpace dataspace = DataSpace(H5S_SCALAR);
             DataSet dataset =
                 group->createDataSet("gates", PredType::STD_U32LE, dataspace);
-            dataset.write(&gates, PredType::STD_U64LE);
+            dataset.write(&gates, PredType::STD_U32LE);
         }
     };
 #endif
diff --git a/slsSupportLib/include/sls_detector_funcs.h b/slsSupportLib/include/sls_detector_funcs.h
index 8d83fbdc5..9692d2dc5 100755
--- a/slsSupportLib/include/sls_detector_funcs.h
+++ b/slsSupportLib/include/sls_detector_funcs.h
@@ -298,7 +298,7 @@ enum detFuncs {
     F_SET_RECEIVER_UDP_PORT2,
     F_SET_RECEIVER_NUM_INTERFACES,
     F_RECEIVER_SET_ADC_MASK_10G,
-    F_RECEIVER_SET_NUM_COUNTERS,
+    F_RECEIVER_SET_COUNTER_MASK,
     F_INCREMENT_FILE_INDEX,
     F_SET_ADDITIONAL_JSON_PARAMETER,
     F_GET_ADDITIONAL_JSON_PARAMETER,
@@ -609,7 +609,7 @@ const char* getFunctionNameFromEnum(enum detFuncs func) {
 	case F_SET_RECEIVER_UDP_PORT2:			return "F_SET_RECEIVER_UDP_PORT2";
 	case F_SET_RECEIVER_NUM_INTERFACES:		return "F_SET_RECEIVER_NUM_INTERFACES";
 	case F_RECEIVER_SET_ADC_MASK_10G:		return "F_RECEIVER_SET_ADC_MASK_10G";
-	case F_RECEIVER_SET_NUM_COUNTERS:		return "F_RECEIVER_SET_NUM_COUNTERS";
+	case F_RECEIVER_SET_COUNTER_MASK:		return "F_RECEIVER_SET_COUNTER_MASK";
 	case F_INCREMENT_FILE_INDEX:			return "F_INCREMENT_FILE_INDEX";
 	case F_SET_ADDITIONAL_JSON_PARAMETER:	return "F_SET_ADDITIONAL_JSON_PARAMETER";
 	case F_GET_ADDITIONAL_JSON_PARAMETER:	return "F_GET_ADDITIONAL_JSON_PARAMETER";
diff --git a/slsSupportLib/include/versionAPI.h b/slsSupportLib/include/versionAPI.h
index 3e77510cb..c08c6ca18 100644
--- a/slsSupportLib/include/versionAPI.h
+++ b/slsSupportLib/include/versionAPI.h
@@ -7,6 +7,6 @@
 #define APICTB 0x200729
 #define APIGOTTHARD 0x200729
 #define APIJUNGFRAU 0x200729
-#define APIMYTHEN3 0x200729
 #define APIMOENCH 0x200729
 #define APIGOTTHARD2 0x200730
+#define APIMYTHEN3 0x200804