diff --git a/RELEASE.txt b/RELEASE.txt
index e70f9e10a..a485871af 100755
--- a/RELEASE.txt
+++ b/RELEASE.txt
@@ -32,6 +32,14 @@ This document describes the differences between 5.1.0 and 5.x.x releases.
     ------
 
     1. Aded settings and threshold features for Mythen3.
+    2. Internal modification of acquire for Mythen3.
+    3. Added getMaster functio for M3
+
+
+    Mythen3 server
+    -----------------
+
+    1. Setting timing to auto, sets timing to trigger for slaves
     
 
 3. Resolved Issues
diff --git a/python/src/detector.cpp b/python/src/detector.cpp
index e8d4ee993..444248d8b 100644
--- a/python/src/detector.cpp
+++ b/python/src/detector.cpp
@@ -1132,6 +1132,10 @@ void init_det(py::module &m) {
              (Result<std::array<ns, 3>>(Detector::*)(sls::Positions) const) &
                  Detector::getGateDelayForAllGates,
              py::arg() = Positions{})
+        .def("getMaster",
+             (Result<bool>(Detector::*)(sls::Positions) const) &
+                 Detector::getMaster,
+             py::arg() = Positions{})
         .def("getNumberOfAnalogSamples",
              (Result<int>(Detector::*)(sls::Positions) const) &
                  Detector::getNumberOfAnalogSamples,
diff --git a/slsDetectorServers/mythen3DetectorServer/bin/mythen3DetectorServer_developer b/slsDetectorServers/mythen3DetectorServer/bin/mythen3DetectorServer_developer
index 927ce6428..23c541edb 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 d20c52354..43580109f 100644
--- a/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c
+++ b/slsDetectorServers/mythen3DetectorServer/slsDetectorFunctionList.c
@@ -1522,8 +1522,16 @@ int setHighVoltage(int val) {
     return highvoltage;
 }
 
+int isMaster(){
+    return !(bus_r(0x18) >> 31);
+}
+
 /* parameters - timing */
 void setTiming(enum timingMode arg) {
+    
+    if (!isMaster() && arg == AUTO_TIMING)
+        arg = TRIGGER_EXPOSURE;
+
     uint32_t addr = CONFIG_REG;
     switch (arg) {
     case AUTO_TIMING:
diff --git a/slsDetectorServers/slsDetectorServer/include/slsDetectorFunctionList.h b/slsDetectorServers/slsDetectorServer/include/slsDetectorFunctionList.h
index 8b241b725..84103f61f 100644
--- a/slsDetectorServers/slsDetectorServer/include/slsDetectorFunctionList.h
+++ b/slsDetectorServers/slsDetectorServer/include/slsDetectorFunctionList.h
@@ -352,6 +352,7 @@ void setTiming(enum timingMode arg);
 enum timingMode getTiming();
 #ifdef MYTHEN3D
 void setInitialExtSignals();
+int isMaster();
 #endif
 #if defined(GOTTHARDD) || defined(MYTHEN3D)
 void setExtSignal(int signalIndex, enum externalSignalFlag mode);
diff --git a/slsDetectorServers/slsDetectorServer/include/slsDetectorServer_funcs.h b/slsDetectorServers/slsDetectorServer/include/slsDetectorServer_funcs.h
index 0938a328c..62a947254 100644
--- a/slsDetectorServers/slsDetectorServer/include/slsDetectorServer_funcs.h
+++ b/slsDetectorServers/slsDetectorServer/include/slsDetectorServer_funcs.h
@@ -245,4 +245,5 @@ int set_default_dacs(int);
 int is_virtual(int);
 int get_pattern(int);
 int load_default_pattern(int);
-int get_all_threshold_energy(int);
\ No newline at end of file
+int get_all_threshold_energy(int);
+int get_master(int);
\ No newline at end of file
diff --git a/slsDetectorServers/slsDetectorServer/src/slsDetectorServer_funcs.c b/slsDetectorServers/slsDetectorServer/src/slsDetectorServer_funcs.c
index eae2ecd4e..09da78b48 100644
--- a/slsDetectorServers/slsDetectorServer/src/slsDetectorServer_funcs.c
+++ b/slsDetectorServers/slsDetectorServer/src/slsDetectorServer_funcs.c
@@ -368,6 +368,7 @@ void function_table() {
     flist[F_GET_PATTERN] = &get_pattern;
     flist[F_LOAD_DEFAULT_PATTERN] = &load_default_pattern;
     flist[F_GET_ALL_THRESHOLD_ENERGY] = &get_all_threshold_energy;
+    flist[F_GET_MASTER] = &get_master;
 
     // check
     if (NUM_DET_FUNCTIONS >= RECEIVER_ENUM_START) {
@@ -638,7 +639,9 @@ int set_timing_mode(int file_des) {
     }
     // get
     retval = getTiming();
+    #ifndef MYTHEN3D
     validate((int)arg, (int)retval, "set timing mode", DEC);
+    #endif
     LOG(logDEBUG1, ("Timing Mode: %d\n", retval));
 
     return Server_SendResult(file_des, INT32, &retval, sizeof(retval));
@@ -8365,3 +8368,18 @@ int get_all_threshold_energy(int file_des) {
 #endif
     return Server_SendResult(file_des, INT32, retvals, sizeof(retvals));
 }
+
+int get_master(int file_des){
+    ret = OK;
+    memset(mess, 0, sizeof(mess));
+    int retval = -1;
+
+    LOG(logDEBUG1, ("Getting master\n"));
+
+#ifndef MYTHEN3D
+    functionNotImplemented();
+#else
+    retval = isMaster();
+#endif
+    return Server_SendResult(file_des, INT32, &retval, sizeof(retval));
+}
diff --git a/slsDetectorSoftware/include/sls/Detector.h b/slsDetectorSoftware/include/sls/Detector.h
index bf4a64107..105d95dee 100644
--- a/slsDetectorSoftware/include/sls/Detector.h
+++ b/slsDetectorSoftware/include/sls/Detector.h
@@ -1305,6 +1305,9 @@ class Detector {
     /** [Mythen3] gate delay for all gates in auto or trigger timing mode
      * (internal gating). Gate index: 0-2, -1 for all */
     Result<std::array<ns, 3>> getGateDelayForAllGates(Positions pos = {}) const;
+
+    Result<bool> getMaster(Positions pos = {}) const;
+
     ///@{
 
     /** @name CTB / Moench Specific */
diff --git a/slsDetectorSoftware/src/Detector.cpp b/slsDetectorSoftware/src/Detector.cpp
index 8cf4584e8..1d833a0e4 100644
--- a/slsDetectorSoftware/src/Detector.cpp
+++ b/slsDetectorSoftware/src/Detector.cpp
@@ -674,7 +674,23 @@ void Detector::startReceiver() { pimpl->Parallel(&Module::startReceiver, {}); }
 void Detector::stopReceiver() { pimpl->Parallel(&Module::stopReceiver, {}); }
 
 void Detector::startDetector() {
-    pimpl->Parallel(&Module::startAcquisition, {});
+    auto detector_type = getDetectorType().squash();
+    if (detector_type == defs::MYTHEN3){
+        auto is_master = getMaster();
+        std::vector<int> master;
+        std::vector<int> slaves;
+        for(int i=0; i<size(); ++i){
+            if (is_master[i])
+                master.push_back(i);
+            else
+                slaves.push_back(i);
+        }
+        pimpl->Parallel(&Module::startAcquisition, slaves);
+        pimpl->Parallel(&Module::startAcquisition, master);
+    }else{
+        pimpl->Parallel(&Module::startAcquisition, {});
+    }
+    
 }
 
 void Detector::startDetectorReadout() {
@@ -717,6 +733,9 @@ Result<defs::scanParameters> Detector::getScan(Positions pos) const {
 }
 
 void Detector::setScan(const defs::scanParameters t) {
+    if(getDetectorType().squash() == defs::MYTHEN3 && size()>1 && t.enable != 0){
+        throw DetectorError("Scan is only allowed for single module Mythen 3 because of synchronization");
+    }
     pimpl->Parallel(&Module::setScan, {}, t);
 }
 
@@ -1592,6 +1611,11 @@ Detector::getGateDelayForAllGates(Positions pos) const {
     return pimpl->Parallel(&Module::getGateDelayForAllGates, pos);
 }
 
+Result<bool> Detector::getMaster(Positions pos) const{
+    return pimpl->Parallel(&Module::isMaster, pos);
+}
+
+
 // CTB/ Moench Specific
 
 Result<int> Detector::getNumberOfAnalogSamples(Positions pos) const {
diff --git a/slsDetectorSoftware/src/DetectorImpl.cpp b/slsDetectorSoftware/src/DetectorImpl.cpp
index 925d95106..188b53167 100644
--- a/slsDetectorSoftware/src/DetectorImpl.cpp
+++ b/slsDetectorSoftware/src/DetectorImpl.cpp
@@ -1056,11 +1056,15 @@ void DetectorImpl::registerDataCallback(void (*userCallback)(detectorData *,
 }
 
 int DetectorImpl::acquire() {
+
     // ensure acquire isnt started multiple times by same client
     if (!isAcquireReady()) {
         return FAIL;
     }
 
+    // We need this to handle Mythen3 synchronization
+    auto detector_type = Parallel(&Module::getDetectorType, {}).squash();
+
     try {
         struct timespec begin, end;
         clock_gettime(CLOCK_REALTIME, &begin);
@@ -1088,7 +1092,25 @@ int DetectorImpl::acquire() {
 
         // start and read all
         try {
-            Parallel(&Module::startAndReadAll, {});
+            if(detector_type == defs::MYTHEN3 && detectors.size() > 1){
+                //Multi module mythen
+                std::vector<int> master;
+                std::vector<int> slaves;
+                auto is_master = Parallel(&Module::isMaster, {});
+                slaves.reserve(detectors.size()-1); //check this one!!
+                for (size_t i = 0; i<detectors.size(); ++i){
+                    if(is_master[i])
+                        master.push_back(i);
+                    else
+                        slaves.push_back(i);
+                }
+                Parallel(&Module::startAcquisition, slaves);
+                Parallel(&Module::startAndReadAll, master);
+            }else{
+                //Normal acquire
+                Parallel(&Module::startAndReadAll, {});
+            }
+            
         } catch (...) {
             if (receiver)
                 Parallel(&Module::stopReceiver, {});
diff --git a/slsDetectorSoftware/src/Module.cpp b/slsDetectorSoftware/src/Module.cpp
index 6499066ca..c5a570ea7 100644
--- a/slsDetectorSoftware/src/Module.cpp
+++ b/slsDetectorSoftware/src/Module.cpp
@@ -1994,6 +1994,10 @@ std::array<time::ns, 3> Module::getGateDelayForAllGates() const {
     return sendToDetector<std::array<time::ns, 3>>(F_GET_GATE_DELAY_ALL_GATES);
 }
 
+bool Module::isMaster() const{
+    return sendToDetector<int>(F_GET_MASTER);
+}
+
 // CTB / Moench Specific
 int Module::getNumberOfAnalogSamples() const {
     return sendToDetector<int>(F_GET_NUM_ANALOG_SAMPLES);
diff --git a/slsDetectorSoftware/src/Module.h b/slsDetectorSoftware/src/Module.h
index e8bd0f48f..a1c52d0f7 100644
--- a/slsDetectorSoftware/src/Module.h
+++ b/slsDetectorSoftware/src/Module.h
@@ -425,6 +425,7 @@ class Module : public virtual slsDetectorDefs {
     int64_t getGateDelay(int gateIndex) const;
     void setGateDelay(int gateIndex, int64_t value);
     std::array<time::ns, 3> getGateDelayForAllGates() const;
+    bool isMaster() const;
 
     /**************************************************
      *                                                *
diff --git a/slsSupportLib/include/sls/sls_detector_funcs.h b/slsSupportLib/include/sls/sls_detector_funcs.h
index d0f50f696..9abb18d7f 100755
--- a/slsSupportLib/include/sls/sls_detector_funcs.h
+++ b/slsSupportLib/include/sls/sls_detector_funcs.h
@@ -220,6 +220,7 @@ enum detFuncs {
     F_GET_PATTERN,
     F_LOAD_DEFAULT_PATTERN,
     F_GET_ALL_THRESHOLD_ENERGY,
+    F_GET_MASTER,
 
     NUM_DET_FUNCTIONS,
     RECEIVER_ENUM_START = 256, /**< detector function should not exceed this
@@ -546,6 +547,7 @@ const char* getFunctionNameFromEnum(enum detFuncs func) {
     case F_GET_PATTERN:                     return "F_GET_PATTERN";
     case F_LOAD_DEFAULT_PATTERN:            return "F_LOAD_DEFAULT_PATTERN";
     case F_GET_ALL_THRESHOLD_ENERGY:        return "F_GET_ALL_THRESHOLD_ENERGY";
+    case F_GET_MASTER:                      return "F_GET_MASTER";
 
     case NUM_DET_FUNCTIONS:              	return "NUM_DET_FUNCTIONS";
     case RECEIVER_ENUM_START:				return "RECEIVER_ENUM_START";