diff --git a/slsDetectorSoftware/include/sls/Detector.h b/slsDetectorSoftware/include/sls/Detector.h
index aaca367ec..b0a261e94 100644
--- a/slsDetectorSoftware/include/sls/Detector.h
+++ b/slsDetectorSoftware/include/sls/Detector.h
@@ -989,15 +989,17 @@ class Detector {
      * every minute. Useful in 10G mode. */
     void setRxArping(bool value, Positions pos = {});
 
+    /** Returns multi level ROIs */
     std::vector<defs::ROI> getRxROI() const;
 
-    /** only at multi module level without gap pixels */
+    /** Returns port level ROIs. Max 2 ports and hence max 2 elements per readout */
+    Result<std::array<defs::ROI, 2>> getRxROI(int module_id) const;
+
+    /** only at multi module level without gap pixels. At most, 1 ROI per UDP port */
     void setRxROI(const std::vector<defs::ROI> &args);
 
     void clearRxROI();
 
-    int getNumberOfUdpPortsInRxROI() const;
-
     ///@}
 
     /** @name File */
diff --git a/slsDetectorSoftware/src/CallerSpecial.cpp b/slsDetectorSoftware/src/CallerSpecial.cpp
index bb0cfdf2f..9ceb3803a 100644
--- a/slsDetectorSoftware/src/CallerSpecial.cpp
+++ b/slsDetectorSoftware/src/CallerSpecial.cpp
@@ -739,14 +739,7 @@ std::string Caller::rx_roi(int action) {
             throw RuntimeError("Cannot execute receiver ROI at module level");
         } else {
             auto t = det->getRxROI();
-            // os << ToString(t) << '\n';
-            for (const auto &r : t) {
-                os << r << ';';
-            }
-            if (!t.empty()) {
-                os.seekp(-1, std::ios_base::end); // remove trailing ;
-            }
-            os << '\n';
+            os << ToString(t) << '\n';
         }
     } else if (action == defs::PUT_ACTION) {
         std::vector<defs::ROI> rois;
@@ -789,14 +782,7 @@ std::string Caller::rx_roi(int action) {
         }
 
         det->setRxROI(rois);
-        // os << ToString(rois) << '\n';
-        for (const auto &r : rois) {
-            os << r << ';';
-        }
-        //if (!rois.empty()) {
-       //     os.seekp(-1, std::ios_base::end); // remove trailing ;
-        //}
-        os << '\n';
+        os << ToString(rois) << '\n';
     } else {
         throw RuntimeError("Unknown action");
     }
diff --git a/slsDetectorSoftware/src/Detector.cpp b/slsDetectorSoftware/src/Detector.cpp
index 960b84654..a274f06f7 100644
--- a/slsDetectorSoftware/src/Detector.cpp
+++ b/slsDetectorSoftware/src/Detector.cpp
@@ -1383,7 +1383,13 @@ void Detector::setRxArping(bool value, Positions pos) {
     pimpl->Parallel(&Module::setRxArping, pos, value);
 }
 
-std::vector<defs::ROI> Detector::getRxROI() const { return pimpl->getRxROI(); }
+std::vector<defs::ROI> Detector::getRxROI() const { 
+    return pimpl->getRxROI(); 
+}
+
+Result<std::array<defs::ROI, 2>> Detector::getRxROI(int module_id) const {
+    return pimpl->Parallel(&Module::getRxROI, {module_id});
+}
 
 // RxROIs can be set for all types except CTB. At multi level without gap pixels
 void Detector::setRxROI(const std::vector<defs::ROI> &args) {
@@ -1392,9 +1398,6 @@ void Detector::setRxROI(const std::vector<defs::ROI> &args) {
 
 void Detector::clearRxROI() { pimpl->clearRxROI(); }
 
-int Detector::getNumberOfUdpPortsInRxROI() const {
-    return pimpl->getNumberOfUdpPortsInRxROI();
-}
 
 // File
 
diff --git a/slsDetectorSoftware/src/DetectorImpl.cpp b/slsDetectorSoftware/src/DetectorImpl.cpp
index 7e405d7a8..1fa906dc3 100644
--- a/slsDetectorSoftware/src/DetectorImpl.cpp
+++ b/slsDetectorSoftware/src/DetectorImpl.cpp
@@ -1791,7 +1791,7 @@ defs::ROI DetectorImpl::getModuleROI(int moduleIndex) const {
 
 void DetectorImpl::convertGlobalRoiToPortLevel(
     const defs::ROI &userRoi, const defs::ROI &moduleRoi,
-    std::vector<std::map<int, defs::ROI>> &portRois) const {
+    std::array<defs::ROI, 2> &portRois) const {
     const defs::xy modSize = modules[0]->getNumberOfChannels();
     const defs::xy geometry = getPortGeometry();
     const int numPorts = geometry.x * geometry.y;
@@ -1827,16 +1827,13 @@ void DetectorImpl::convertGlobalRoiToPortLevel(
             }
 
             // Check if port ROI already exists for this port
-            for (const auto &m : portRois) {
-                if (m.find(port) != m.end()) {
-                    throw RuntimeError(
-                        "Multiple ROIs specified for the same port " +
-                        std::to_string(port) +
-                        " with ROI: " + ToString(userRoi));
-                }
+            if (!portRois[port].completeRoi()) {
+                throw RuntimeError(
+                    "Multiple ROIs specified for the same port " +
+                    std::to_string(port) +
+                    " with ROI: " + ToString(userRoi));
             }
-
-            portRois.push_back({{port, clipped}});
+            portRois[port] = clipped;
         }
     }
 }
@@ -1856,7 +1853,7 @@ void DetectorImpl::setRxROI(const std::vector<defs::ROI> &args) {
         auto moduleGlobalRoi = getModuleROI(iModule);
 
         // at most 2 rois per module (for each port)
-        std::vector<std::map<int, defs::ROI>> portRois;
+        std::array<defs::ROI, 2> portRois{};
 
         for (const auto &arg : args) {
             if (roisOverlap(arg, moduleGlobalRoi)) {
@@ -1865,18 +1862,23 @@ void DetectorImpl::setRxROI(const std::vector<defs::ROI> &args) {
         }
         // print the rois for debugging
         LOG(logINFOBLUE) << "Module " << iModule << " RxROIs:";
-        for (const auto &portRoi : portRois) {
-            for (const auto &roi : portRoi) {
-                LOG(logINFOBLUE)
-                    << "  Port " << roi.first << ": " << ToString(roi.second);
-            }
+        for (size_t iPort = 0; iPort != 2; iPort++) {
+            LOG(logINFOBLUE)
+                    << "  Port " << iPort << ": " << ToString(portRois[iPort]);
         }
-        // modules[iModule]->setRxROIs(portRois); TODO
+        modules[iModule]->setRxROI(portRois);
     }
     rxRoiTemp = args;
+    // metadata
+    modules[0]->setRxROIMetadata(args);
 }
 
-void DetectorImpl::clearRxROI() { rxRoiTemp.clear(); }
+void DetectorImpl::clearRxROI() { 
+    rxRoiTemp.clear();
+    for (size_t iModule = 0; iModule < modules.size(); ++iModule) {
+        modules[iModule]->setRxROI(std::array<defs::ROI, 2>{}); 
+    }
+}
 
 int DetectorImpl::getNumberOfUdpPortsInRxROI() const {
     return 0; // TODO
diff --git a/slsDetectorSoftware/src/DetectorImpl.h b/slsDetectorSoftware/src/DetectorImpl.h
index 4d82088b7..a43707c0c 100644
--- a/slsDetectorSoftware/src/DetectorImpl.h
+++ b/slsDetectorSoftware/src/DetectorImpl.h
@@ -433,7 +433,7 @@ class DetectorImpl : public virtual slsDetectorDefs {
     defs::ROI getModuleROI(int moduleIndex) const;
     void convertGlobalRoiToPortLevel(
         const defs::ROI &userRoi, const defs::ROI &moduleRoi,
-        std::vector<std::map<int, defs::ROI>> &portRois) const;
+        std::array<defs::ROI, 2> &portRois) const;
 
     const int detectorIndex{0};
     SharedMemory<sharedDetector> shm{0, -1};
diff --git a/slsDetectorSoftware/src/Module.cpp b/slsDetectorSoftware/src/Module.cpp
index 47f4ffe79..25af1c403 100644
--- a/slsDetectorSoftware/src/Module.cpp
+++ b/slsDetectorSoftware/src/Module.cpp
@@ -1520,20 +1520,29 @@ bool Module::getRxArping() const {
 void Module::setRxArping(bool enable) {
     sendToReceiver(F_SET_RECEIVER_ARPING, static_cast<int>(enable), nullptr);
 }
-/*
-defs::ROI Module::getRxROI() const {
-    return sendToReceiver<slsDetectorDefs::ROI>(F_RECEIVER_GET_RECEIVER_ROI);
+
+std::array<defs::ROI, 2> Module::getRxROI() const {
+    return sendToReceiver<std::array<slsDetectorDefs::ROI, 2>>(F_RECEIVER_GET_RECEIVER_ROI);
 }
 
-void Module::setRxROI(const slsDetectorDefs::ROI arg) {
-    LOG(logDEBUG) << moduleIndex << ": " << arg;
-    sendToReceiver(F_RECEIVER_SET_RECEIVER_ROI, arg, nullptr);
+void Module::setRxROI(std::array<defs::ROI, 2> portRois) {
+    /*LOG(logDEBUG) << "Sending to receiver " << moduleIndex << " [rx roi: " << ToString(portRois)
+                  << ']';
+    auto receiver = ReceiverSocket(shm()->rxHostname, shm()->rxTCPPort);
+    receiver.Send(F_RECEIVER_SET_RECEIVER_ROI);
+    receiver.setFnum(F_RECEIVER_SET_RECEIVER_ROI);
+    receiver.Send(portRois);
+    if (receiver.Receive<int>() == FAIL) {
+        throw ReceiverError("Receiver " + std::to_string(moduleIndex) +
+                            " returned error: " + receiver.readErrorMessage());
+    }*/
+    sendToReceiver(F_RECEIVER_SET_RECEIVER_ROI, portRois, nullptr);
 }
 
-void Module::setRxROIMetadata(const slsDetectorDefs::ROI arg) {
+void Module::setRxROIMetadata(const std::vector<slsDetectorDefs::ROI> &arg) {
     sendToReceiver(F_RECEIVER_SET_RECEIVER_ROI_METADATA, arg, nullptr);
 }
-*/
+
 // File
 slsDetectorDefs::fileFormat Module::getFileFormat() const {
     return sendToReceiver<fileFormat>(F_GET_RECEIVER_FILE_FORMAT);
diff --git a/slsDetectorSoftware/src/Module.h b/slsDetectorSoftware/src/Module.h
index c84fa378b..ca79f44d7 100644
--- a/slsDetectorSoftware/src/Module.h
+++ b/slsDetectorSoftware/src/Module.h
@@ -301,9 +301,9 @@ class Module : public virtual slsDetectorDefs {
     std::array<pid_t, NUM_RX_THREAD_IDS> getReceiverThreadIds() const;
     bool getRxArping() const;
     void setRxArping(bool enable);
-    // defs::ROI getRxROI() const;
-    // void setRxROI(const slsDetectorDefs::ROI arg);
-    // void setRxROIMetadata(const slsDetectorDefs::ROI arg);
+    std::array<defs::ROI, 2> getRxROI() const;
+    void setRxROI(const std::array<slsDetectorDefs::ROI, 2> portRois);
+    void setRxROIMetadata(const std::vector<slsDetectorDefs::ROI> &args);
 
     /**************************************************
      *                                                *
diff --git a/slsDetectorSoftware/tests/Caller/test-Caller-rx.cpp b/slsDetectorSoftware/tests/Caller/test-Caller-rx.cpp
index aff9ef607..72d4c23a0 100644
--- a/slsDetectorSoftware/tests/Caller/test-Caller-rx.cpp
+++ b/slsDetectorSoftware/tests/Caller/test-Caller-rx.cpp
@@ -482,12 +482,12 @@ TEST_CASE("rx_roi", "[.cmdcall]") {
             {
                 std::ostringstream oss;
                 caller.call("rx_roi", {"5", "10"}, -1, PUT, oss);
-                REQUIRE(oss.str() == "rx_roi [5, 10]\n");
+                REQUIRE(oss.str() == "rx_roi [[5, 10]]\n");
             }
             {
                 std::ostringstream oss;
                 caller.call("rx_roi", {"10", "15"}, -1, PUT, oss);
-                REQUIRE(oss.str() == "rx_roi [10, 15]\n");
+                REQUIRE(oss.str() == "rx_roi [[10, 15]]\n");
             }
             REQUIRE_THROWS(caller.call("rx_roi", {"0", "0"}, -1, PUT));
             REQUIRE_THROWS(caller.call("rx_roi", {"-1", "-1"}, -1, PUT));
@@ -526,7 +526,7 @@ TEST_CASE("rx_roi", "[.cmdcall]") {
                 REQUIRE_NOTHROW(caller.call(
                     "rx_roi", {"[5, 10, -1, -1];[" + stringMin + ", " + stringMax + ", -1, -1]"}, -1, PUT, oss));
                 REQUIRE(oss.str() ==
-                        "rx_roi [5, 10];[" + stringMin + ", " + stringMax + "]\n");
+                        "rx_roi [[5, 10], [" + stringMin + ", " + stringMax + "]]\n");
 
             }
         }
@@ -535,12 +535,12 @@ TEST_CASE("rx_roi", "[.cmdcall]") {
             {
                 std::ostringstream oss;
                 caller.call("rx_roi", {"10", "15", "1", "5"}, -1, PUT, oss);
-                REQUIRE(oss.str() == "rx_roi [10, 15, 1, 5]\n");
+                REQUIRE(oss.str() == "rx_roi [[10, 15, 1, 5]]\n");
             }
             {
                 std::ostringstream oss;
                 caller.call("rx_roi", {"10", "22", "18", "19"}, -1, PUT, oss);
-                REQUIRE(oss.str() == "rx_roi [10, 22, 18, 19]\n");
+                REQUIRE(oss.str() == "rx_roi [[10, 22, 18, 19]]\n");
             }
             {
                 std::ostringstream oss;
@@ -548,11 +548,11 @@ TEST_CASE("rx_roi", "[.cmdcall]") {
                             {"1", std::to_string(detsize.x - 5), "1",
                              std::to_string(detsize.y - 5)},
                             -1, PUT, oss);
-                REQUIRE(oss.str() == std::string("rx_roi [1, ") +
+                REQUIRE(oss.str() == std::string("rx_roi [[1, ") +
                                          std::to_string(detsize.x - 5) +
                                          std::string(", 1, ") +
                                          std::to_string(detsize.y - 5) +
-                                         std::string("]\n"));
+                                         std::string("]]\n"));
             }
             REQUIRE_THROWS(
                 caller.call("rx_roi", {"0", "0", "0", "0"}, -1, PUT));
@@ -600,7 +600,7 @@ TEST_CASE("rx_roi", "[.cmdcall]") {
                 REQUIRE_NOTHROW(caller.call(
                     "rx_roi", {"[5, 10, 20, 30];[" + stringMin + ", " + stringMax + ", 20, 30]"}, -1, PUT, oss));
                 REQUIRE(oss.str() ==
-                    "rx_roi [5, 10, 20, 30];[" + stringMin + ", " + stringMax + ", 20, 30]\n");
+                    "rx_roi [[5, 10, 20, 30], [" + stringMin + ", " + stringMax + ", 20, 30]]\n");
             }
             if (det_type == defs::JUNGFRAU || det_type == defs::MOENCH) {
                 // 2 interfaces or 2 modules
@@ -622,7 +622,7 @@ TEST_CASE("rx_roi", "[.cmdcall]") {
                     REQUIRE_NOTHROW(caller.call(
                         "rx_roi", {"[5, 10, 20, 30];[25, 28, " + stringMin + ", " +  stringMax + "]"}, -1, PUT, oss));
                     REQUIRE(oss.str() ==
-                        "rx_roi [5, 10, 20, 30];[25, 28, " + stringMin + ", " +  stringMax + "]\n");
+                        "rx_roi [[5, 10, 20, 30], [25, 28, " + stringMin + ", " +  stringMax + "]]\n");
                 }
             }
         }
diff --git a/slsSupportLib/include/sls/ToString.h b/slsSupportLib/include/sls/ToString.h
index 55d6b628b..71d9a1190 100644
--- a/slsSupportLib/include/sls/ToString.h
+++ b/slsSupportLib/include/sls/ToString.h
@@ -348,23 +348,6 @@ std::vector<T> StringTo(const std::vector<std::string> &strings) {
         result.push_back(StringTo<T>(s));
     return result;
 }
-/*
-template <typename T>
-std::string ToString(const std::vector<T> &vec) {
-    std::ostringstream oss;
-    oss << "[";
-    for (size_t i = 0; i < vec.size(); ++i) {
-        oss << vec[i];
-        if (i != vec.size() - 1)
-            oss << ", ";
-    }
-    oss << "]";
-    return oss.str();
-}*/
 
-/*template <typename T>
-std::ostream &operator<<(std::ostream &os, const std::vector<T> &v) {
-    return os << ToString(v);
-}*/
 
 } // namespace sls