diff --git a/slsDetectorSoftware/include/slsDetector.h b/slsDetectorSoftware/include/slsDetector.h
index 3f35bbce7..d4264abfb 100755
--- a/slsDetectorSoftware/include/slsDetector.h
+++ b/slsDetectorSoftware/include/slsDetector.h
@@ -6,12 +6,14 @@
 #include "logger.h"
 #include "sls_detector_defs.h"
 #include "network_utils.h"
+#include "FixedCapacityContainer.h"
 class ClientInterface;
 
 #include <cmath>
 #include <vector>
 #include <array>
 
+
 class multiSlsDetector;
 class ServerInterface;
 class MySocketTCP;
@@ -62,11 +64,8 @@ struct sharedSlsDetector {
     /** path of the trimbits/settings files */
     char settingsDir[MAX_STR_LENGTH];
 
-    /** number of energies at which the detector has been trimmed */
-    int nTrimEn;
-
     /** list of the energies at which the detector has been trimmed  */
-    int trimEnergies[MAX_TRIMEN];
+	sls::FixedCapacityContainer<int, MAX_TRIMEN> trimEnergies;
 
     /**  number of channels per chip */
     int nChans;
diff --git a/slsDetectorSoftware/src/slsDetector.cpp b/slsDetectorSoftware/src/slsDetector.cpp
index 05dd882ae..606d0e772 100755
--- a/slsDetectorSoftware/src/slsDetector.cpp
+++ b/slsDetectorSoftware/src/slsDetector.cpp
@@ -300,10 +300,6 @@ void slsDetector::initializeDetectorStructure(detectorType type) {
     shm()->controlPort = DEFAULT_PORTNO;
     shm()->stopPort = DEFAULT_PORTNO + 1;
     sls::strcpy_safe(shm()->settingsDir, getenv("HOME"));
-    shm()->nTrimEn = 0;
-    for (int &trimEnergie : shm()->trimEnergies) {
-        trimEnergie = 0;
-    }
     shm()->nROI = 0;
     memset(shm()->roiLimits, 0, MAX_ROIS * sizeof(ROI));
     shm()->adcEnableMask = BIT32_MASK;
@@ -1166,14 +1162,14 @@ int slsDetector::setThresholdEnergyAndSettings(int e_eV,
         ((isettings != GET_SETTINGS) ? isettings : shm()->currentSettings);
 
     // verify e_eV exists in trimEneregies[]
-    if ((shm()->nTrimEn == 0) || (e_eV < shm()->trimEnergies[0]) ||
-        (e_eV > shm()->trimEnergies[shm()->nTrimEn - 1])) {
+    if (shm()->trimEnergies.empty() || (e_eV < shm()->trimEnergies.front()) ||
+        (e_eV > shm()->trimEnergies.back())) {
         throw RuntimeError("This energy " + std::to_string(e_eV) +
                            " not defined for this module!");
     }
 
     bool interpolate =
-        std::all_of(shm()->trimEnergies, shm()->trimEnergies + shm()->nTrimEn,
+        std::all_of(shm()->trimEnergies.begin(), shm()->trimEnergies.end(),
                     [e_eV](const int &e) { return e != e_eV; });
 
     sls_detector_module myMod{shm()->myDetectorType};
@@ -1185,7 +1181,7 @@ int slsDetector::setThresholdEnergyAndSettings(int e_eV,
     } else {
         // find the trim values
         int trim1 = -1, trim2 = -1;
-        for (int i = 0; i < shm()->nTrimEn; ++i) {
+        for (size_t i = 0; i < shm()->trimEnergies.size(); ++i) {
             if (e_eV < shm()->trimEnergies[i]) {
                 trim2 = shm()->trimEnergies[i];
                 trim1 = shm()->trimEnergies[i - 1];
@@ -2908,14 +2904,13 @@ int slsDetector::setTrimEn(std::vector<int> energies) {
            << "\n";
         throw RuntimeError(os.str());
     }
-    std::copy(begin(energies), end(energies), shm()->trimEnergies);
-    shm()->nTrimEn = energies.size();
-    return shm()->nTrimEn;
+    shm()->trimEnergies = energies;
+    return shm()->trimEnergies.size();
 }
 
 std::vector<int> slsDetector::getTrimEn() {
-    return std::vector<int>(shm()->trimEnergies,
-                            shm()->trimEnergies + shm()->nTrimEn);
+    return std::vector<int>(shm()->trimEnergies.begin(),
+                            shm()->trimEnergies.end());
 }
 
 int slsDetector::pulsePixel(int n, int x, int y) {
diff --git a/slsSupportLib/CMakeLists.txt b/slsSupportLib/CMakeLists.txt
index ae44b93c6..6e2c640a6 100755
--- a/slsSupportLib/CMakeLists.txt
+++ b/slsSupportLib/CMakeLists.txt
@@ -32,6 +32,7 @@ set(PUBLICHEADERS
     include/ServerSocket.h
     include/ServerInterface.h
     include/network_utils.h
+    include/FixedCapacityContainer.h
 )
 
 add_library(slsSupportLib SHARED
diff --git a/slsSupportLib/include/FixedCapacityContainer.h b/slsSupportLib/include/FixedCapacityContainer.h
new file mode 100644
index 000000000..046f5b1f3
--- /dev/null
+++ b/slsSupportLib/include/FixedCapacityContainer.h
@@ -0,0 +1,172 @@
+
+#pragma once
+#include <array>
+#include <cassert>
+#include <stdexcept>
+#include <vector>
+
+namespace sls {
+template <typename T, size_t Capacity> class FixedCapacityContainer {
+  public:
+    FixedCapacityContainer() = default;
+    explicit FixedCapacityContainer(std::initializer_list<T> l);
+    explicit FixedCapacityContainer(const std::vector<T> &v);
+
+    FixedCapacityContainer &operator=(const std::vector<T> &other);
+
+    bool operator==(const std::vector<T> &other) const;
+    bool operator!=(const std::vector<T> &other) const;
+
+    template <size_t OtherCapacity>
+    bool
+    operator==(const FixedCapacityContainer<T, OtherCapacity> &other) const;
+
+    template <size_t OtherCapacity>
+    bool
+    operator!=(const FixedCapacityContainer<T, OtherCapacity> &other) const;
+
+    T &operator[](size_t i) { return data_[i]; }
+    const T &operator[](size_t i) const { return data_[i]; }
+
+    size_t size() const { return size_; }
+    bool empty() const{ return size_ == 0;}
+    size_t capacity() const { return Capacity; }
+
+    void push_back(const T &value);
+    void resize(size_t new_size);
+    void erase(T *ptr);
+    T &front() { return data_.front(); }
+    T &back() { return data_[size_ - 1]; }
+    const T &front() const { return data_.front(); }
+    const T &back() const { return data_[size_ - 1]; }
+
+    // iterators
+    T *begin() { return &data_[0]; }
+    T *end() { return &data_[size_]; }
+    const T *cbegin() const { return &data_[0]; }
+    const T *cend() const { return &data_[size_]; }
+
+  private:
+    size_t size_{0};
+    std::array<T, Capacity> data_;
+} __attribute__((packed));
+
+/* Member functions */
+template <typename T, size_t Capacity>
+FixedCapacityContainer<T, Capacity>::FixedCapacityContainer(
+    std::initializer_list<T> l) {
+    size_ = l.size();
+    std::copy(l.begin(), l.end(), data_.begin());
+}
+
+template <typename T, size_t Capacity>
+FixedCapacityContainer<T, Capacity>::FixedCapacityContainer(
+    const std::vector<T> &v) {
+    size_ = v.size();
+    std::copy(v.begin(), v.end(), data_.begin());
+}
+
+template <typename T, size_t Capacity>
+void FixedCapacityContainer<T, Capacity>::push_back(const T &value) {
+    if (size_ == Capacity) {
+        throw std::runtime_error("Container is full");
+    } else {
+        data_[size_] = value;
+        ++size_;
+    }
+}
+template <typename T, size_t Capacity>
+void FixedCapacityContainer<T, Capacity>::resize(size_t new_size) {
+    if (new_size > Capacity) {
+        throw std::runtime_error("Cannot resize beyond capacity");
+    } else {
+        size_ = new_size;
+    }
+}
+
+template <typename T, size_t Capacity>
+FixedCapacityContainer<T, Capacity> &FixedCapacityContainer<T, Capacity>::
+operator=(const std::vector<T> &other) {
+    std::copy(other.begin(), other.end(), data_.begin());
+    size_ = other.size();
+    return *this;
+}
+
+template <typename T, size_t Capacity>
+bool FixedCapacityContainer<T, Capacity>::
+operator==(const std::vector<T> &other) const {
+    if (size_ != other.size()) {
+        return false;
+    } else {
+        for (size_t i = 0; i != size_; ++i) {
+            if (data_[i] != other[i]) {
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+template <typename T, size_t Capacity>
+bool FixedCapacityContainer<T, Capacity>::
+operator!=(const std::vector<T> &other) const {
+    return !(*this == other);
+}
+
+template <typename T, size_t Capacity>
+template <size_t OtherCapacity>
+bool FixedCapacityContainer<T, Capacity>::
+operator==(const FixedCapacityContainer<T, OtherCapacity> &other) const {
+    if (size_ != other.size()) {
+        return false;
+    } else {
+        for (size_t i = 0; i != size_; ++i) {
+            if (data_[i] != other[i]) {
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+template <typename T, size_t Capacity>
+template <size_t OtherCapacity>
+bool FixedCapacityContainer<T, Capacity>::
+operator!=(const FixedCapacityContainer<T, OtherCapacity> &other) const {
+    return !(*this == other);
+}
+
+template <typename T, size_t Capacity>
+void FixedCapacityContainer<T, Capacity>::erase(T *ptr) {
+    if (ptr >= begin() && ptr < end()) {
+        size_ = static_cast<size_t>(ptr - begin());
+    } else {
+        throw std::runtime_error("tried to erase with a ptr outside obj");
+    }
+}
+
+/* Free function concerning FixedCapacityContainer */
+
+template <typename T, size_t Capacity>
+T *begin(FixedCapacityContainer<T, Capacity> &container) {
+    return container.begin();
+}
+
+template <typename T, size_t Capacity>
+T *end(FixedCapacityContainer<T, Capacity> &container) {
+    return container.end();
+}
+
+template <typename T, size_t Capacity>
+bool operator==(const std::vector<T> &vec,
+                const FixedCapacityContainer<T, Capacity> &fixed_container) {
+    return fixed_container == vec;
+}
+
+template <typename T, size_t Capacity>
+bool operator!=(const std::vector<T> &vec,
+                const FixedCapacityContainer<T, Capacity> &fixed_container) {
+    return fixed_container != vec;
+}
+
+} // namespace sls
diff --git a/slsSupportLib/tests/CMakeLists.txt b/slsSupportLib/tests/CMakeLists.txt
index be9ef61f3..e1a7e7d77 100755
--- a/slsSupportLib/tests/CMakeLists.txt
+++ b/slsSupportLib/tests/CMakeLists.txt
@@ -7,4 +7,5 @@ target_sources(tests PRIVATE
                 ${CMAKE_CURRENT_SOURCE_DIR}/test-Timer.cpp
                 ${CMAKE_CURRENT_SOURCE_DIR}/test-sls_detector_defs.cpp
                 ${CMAKE_CURRENT_SOURCE_DIR}/test-Sockets.cpp
+                ${CMAKE_CURRENT_SOURCE_DIR}/test-FixedCapacityContainer.cpp
                 )
\ No newline at end of file
diff --git a/slsSupportLib/tests/test-FixedCapacityContainer.cpp b/slsSupportLib/tests/test-FixedCapacityContainer.cpp
new file mode 100644
index 000000000..78215d336
--- /dev/null
+++ b/slsSupportLib/tests/test-FixedCapacityContainer.cpp
@@ -0,0 +1,205 @@
+#include "FixedCapacityContainer.h"
+#include "catch.hpp"
+
+using sls::FixedCapacityContainer;
+
+SCENARIO("FixedCapacityContainers can be sized and resized", "[support]") {
+
+    GIVEN("A default constructed container") {
+        constexpr size_t n_elem = 5;
+        FixedCapacityContainer<int, n_elem> vec;
+
+        REQUIRE(vec.empty());
+        REQUIRE(vec.size() == 0);
+        REQUIRE(vec.capacity() == n_elem);
+        REQUIRE(sizeof(vec) == sizeof(int) * n_elem + sizeof(size_t));
+
+        WHEN("an item is pushed back") {
+            vec.push_back(42);
+
+            THEN("the element is stored and the size increases but the "
+                 "capacity remains fixed") {
+                REQUIRE(vec[0] == 42);
+                REQUIRE(vec.size() == 1);
+                REQUIRE_FALSE(vec.empty());
+                REQUIRE(vec.capacity() == 5);
+            }
+        }
+
+        WHEN("We try to push back more elements than the capcity") {
+            for (size_t i = 0; i != vec.capacity(); ++i)
+                vec.push_back(static_cast<int>(i));
+            THEN("It throws") { REQUIRE_THROWS(vec.push_back(92)); }
+        }
+
+        WHEN("a vector is assigned to the fixed container") {
+            std::vector<int> standard_vector{1, 2, 8, 0};
+            vec = standard_vector;
+            THEN("their values and size match") {
+                REQUIRE(vec.size() == standard_vector.size());
+                for (size_t i = 0; i != vec.size(); ++i) {
+                    REQUIRE(vec[i] == standard_vector[i]);
+                }
+            }
+        }
+    }
+
+    GIVEN("A FixedCapacityContainer constructed form a std::initializer list") {
+        FixedCapacityContainer<int, 10> vec{23, 52, 11};
+        REQUIRE(vec.size() == 3);
+        REQUIRE(vec.capacity() == 10);
+        REQUIRE(vec[0] == 23);
+        REQUIRE(vec[1] == 52);
+        REQUIRE(vec[2] == 11);
+
+        WHEN("The container is resized to a smaller size") {
+            vec.resize(2);
+            THEN("The size changes but not the values or capacity") {
+                REQUIRE(vec.size() == 2);
+                REQUIRE(vec[0] == 23);
+                REQUIRE(vec[1] == 52);
+            }
+        }
+
+        WHEN("The container is resized to a larger size") {
+            vec.resize(7);
+            THEN("The size changes but not the values") {
+                REQUIRE(vec.size() == 7);
+                REQUIRE(vec[0] == 23);
+                REQUIRE(vec[1] == 52);
+                REQUIRE(vec[2] == 11);
+            }
+        }
+
+        WHEN("We try to resize beyond the capacity") {
+            THEN("it throws") { CHECK_THROWS(vec.resize(25)); }
+        }
+        WHEN("We call front and back"){
+            THEN("They return referenced to the first and last element"){
+                REQUIRE(vec.front() == 23);
+                REQUIRE(&vec.front() == &vec[0]);
+                REQUIRE(vec.back() == 11);
+                REQUIRE(&vec.back() == &vec[2]);
+
+            }
+        }
+    }
+
+    GIVEN("An std::vector of size 3") {
+        std::vector<int> standard_vector{5, 2, 1};
+        WHEN("we construct a fixed capacity container from it") {
+            FixedCapacityContainer<int, 5> vec(standard_vector);
+            THEN("size and data matches") {
+                REQUIRE(vec.size() == 3);
+                REQUIRE(vec[0] == 5);
+                REQUIRE(vec[1] == 2);
+                REQUIRE(vec[2] == 1);
+            }
+            THEN("we can compare the vector and fixed container") {
+                REQUIRE(vec == standard_vector);
+            }
+        }
+    }
+}
+
+SCENARIO("Comparison of FixedCapacityContainers", "[support]") {
+    GIVEN("Two containers containers that are equal at the start") {
+        FixedCapacityContainer<int, 5> a{0, 1, 2};
+        FixedCapacityContainer<int, 5> b{0, 1, 2};
+        REQUIRE(a == b);
+        REQUIRE_FALSE(a != b);
+
+        WHEN("We push back one element") {
+            a.push_back(4);
+            THEN("they are not equal anymore") { REQUIRE(a != b); }
+        }
+        WHEN("Compared to a FixedCapacityContainer with different capacity") {
+            FixedCapacityContainer<int, 8> c{0, 1, 2};
+            THEN("The comparison still holds") {
+                REQUIRE(a == c);
+                REQUIRE_FALSE(a != c);
+            }
+        }
+        WHEN("we make a copy of one container") {
+            auto c = a;
+            THEN("The comparison holds") {
+                REQUIRE(c == a);
+                REQUIRE(&c != &a);
+                REQUIRE(&a[0] != &c[0]);
+            }
+        }
+        WHEN("Compared to an std::vector") {
+            std::vector<int> standard_vector{0, 1, 2};
+            THEN("The comparison also holds for both orderings") {
+                REQUIRE(a == standard_vector);
+                REQUIRE(standard_vector == a);
+                REQUIRE_FALSE(a != standard_vector);
+                REQUIRE_FALSE(standard_vector != a);
+
+                standard_vector.push_back(3);
+                REQUIRE(a != standard_vector);
+            }
+        }
+    }
+}
+
+SCENARIO("Sorting, removing and other manipulation of a container", "[support]") {
+    GIVEN("An unsorted container") {
+        FixedCapacityContainer<int, 5> a{14, 12, 90, 12};
+        WHEN("We sort it") {
+            std::sort(a.begin(), a.end());
+            THEN("Elements appear sorted") {
+                REQUIRE(a[0] == 12);
+                REQUIRE(a[1] == 12);
+                REQUIRE(a[2] == 14);
+                REQUIRE(a[3] == 90);
+            }
+        }
+        WHEN("Sorting is done using free function for begin and end") {
+            std::sort(begin(a), end(a));
+            THEN("it also works") {
+                REQUIRE(a[0] == 12);
+                REQUIRE(a[1] == 12);
+                REQUIRE(a[2] == 14);
+                REQUIRE(a[3] == 90);
+            }
+        }
+        WHEN("Erasing elements of a certain value") {
+            a.erase(std::remove(begin(a), end(a), 12));
+            THEN("all elements of that value are removed") {
+                REQUIRE(a.size() == 2);
+                REQUIRE(a[0] == 14);
+                REQUIRE(a[1] == 90);
+            }
+        }
+    }
+}
+
+SCENARIO("Assigning containers to each other", "[support]") {
+    GIVEN("Two containers") {
+        FixedCapacityContainer<int, 3> a{1, 2, 3};
+        FixedCapacityContainer<int, 3> b{4, 5, 6};
+        WHEN("a is assigned to b") {
+            a = b;
+            THEN("A deep copy is made and both containers are equal") {
+                REQUIRE(a == b);
+                REQUIRE(&a != &b);
+                REQUIRE(&a[0] != &b[0]);
+                REQUIRE(a[0] == 4);
+                REQUIRE(a[1] == 5);
+                REQUIRE(a[2] == 6);
+            }
+        }
+        WHEN("A new object is create from an old one") {
+            FixedCapacityContainer<int, 3> c(a);
+            THEN("A deep copy is also made") {
+                REQUIRE(c == a);
+                REQUIRE(&c != &a);
+                REQUIRE(&c[0] != &a[0]);
+                REQUIRE(c[0] == 1);
+                REQUIRE(c[1] == 2);
+                REQUIRE(c[2] == 3);
+            }
+        }
+    }
+}
\ No newline at end of file