diff --git a/slsDetectorSoftware/src/CmdProxy.cpp b/slsDetectorSoftware/src/CmdProxy.cpp
index 857a9e838..6a92d6648 100644
--- a/slsDetectorSoftware/src/CmdProxy.cpp
+++ b/slsDetectorSoftware/src/CmdProxy.cpp
@@ -1008,7 +1008,7 @@ std::string CmdProxy::Scan(int action) {
             WrongNumberOfParameters(0);
         }
         auto t = det->getScan();
-        os << ToString(t) << '\n';
+        os << OutString(t) << '\n';
     } else if (action == defs::PUT_ACTION) {
         // disable
         if (args.size() == 1) {
diff --git a/slsSupportLib/include/sls_detector_defs.h b/slsSupportLib/include/sls_detector_defs.h
index 8a12f37a3..733d4afb2 100644
--- a/slsSupportLib/include/sls_detector_defs.h
+++ b/slsSupportLib/include/sls_detector_defs.h
@@ -474,6 +474,13 @@ typedef struct {
               stepSize(step) {
             dacSettleTime_ns = t.count();
         }
+        bool operator==(const scanParameters &other) const {
+            return ((enable == other.enable) && (dacInd == other.dacInd) &&
+                    (startOffset == other.startOffset) &&
+                    (stopOffset == other.stopOffset) &&
+                    (stepSize == other.stepSize) &&
+                    (dacSettleTime_ns == other.dacSettleTime_ns));
+        }
     } __attribute__((packed));
 #endif
 
diff --git a/slsSupportLib/tests/test-sls_detector_defs.cpp b/slsSupportLib/tests/test-sls_detector_defs.cpp
index 0162d92b7..d0c28e43c 100644
--- a/slsSupportLib/tests/test-sls_detector_defs.cpp
+++ b/slsSupportLib/tests/test-sls_detector_defs.cpp
@@ -49,4 +49,26 @@ TEST_CASE("assign module", "[support]") {
     CHECK(m3.reg == 500);
     CHECK(m3.iodelay == 750);
     CHECK(m3.nchan == 256 * 256 * 4);
+}
+
+TEST_CASE("default construct scanParameters"){
+    slsDetectorDefs::scanParameters p;
+    CHECK(p.dacSettleTime_ns == 0);
+    CHECK(p.dacInd == slsDetectorDefs::DAC_0);
+    CHECK(p.enable == 0);
+    CHECK(p.startOffset == 0);
+    CHECK(p.stopOffset == 0);
+    CHECK(p.stepSize == 0);
+
+}
+
+TEST_CASE("compare two scanParameters"){
+    slsDetectorDefs::scanParameters p0;
+    slsDetectorDefs::scanParameters p1;
+
+    CHECK(p0 == p1);
+
+    p0.enable = 1;
+    CHECK_FALSE(p0 == p1);
+
 }
\ No newline at end of file