diff --git a/sf-stream/include/LiveRecvModule.hpp b/sf-stream/include/LiveRecvModule.hpp
index d0820ef..f6d247b 100644
--- a/sf-stream/include/LiveRecvModule.hpp
+++ b/sf-stream/include/LiveRecvModule.hpp
@@ -21,7 +21,7 @@ class LiveRecvModule {
     void receive_thread();
     void recv_single_module(void* socket, ModuleFrame* meta, char* data);
     uint64_t align_modules(const std::vector<void*>& sockets,
-                           ModuleFrameBuffer *metadata,
+                           ModuleFrameBuffer *meta,
                            char *data);
     void stop();
 
diff --git a/sf-stream/src/LiveRecvModule.cpp b/sf-stream/src/LiveRecvModule.cpp
index ba4d072..bd7ef05 100644
--- a/sf-stream/src/LiveRecvModule.cpp
+++ b/sf-stream/src/LiveRecvModule.cpp
@@ -92,34 +92,35 @@ void LiveRecvModule::recv_single_module(
 }
 
 uint64_t LiveRecvModule::align_modules(
-        const vector<void*>& sockets, ModuleFrameBuffer *metadata, char *data)
+        const vector<void*>& sockets, ModuleFrameBuffer *meta, char *data)
 {
     uint64_t max_pulse_id = 0;
+    uint64_t min_pulse_id = numeric_limits<uint64_t>::max();
 
-    // First pass - determine current max_pulse_id.
-    for (size_t i_module = 0; i_module < n_modules_; i_module++) {
-        auto& module_metadata = metadata->module[i_module];
-        max_pulse_id = max(max_pulse_id, module_metadata.pulse_id);
+    // First pass - determine current min and max pulse_id.
+    for (auto& module_meta : meta->module) {
+        min_pulse_id = min(min_pulse_id, module_meta.pulse_id);
+        max_pulse_id = max(max_pulse_id, module_meta.pulse_id);
     }
 
     // Second pass - align all receivers to max_pulse_id.
     for (size_t i_module = 0; i_module < n_modules_; i_module++) {
-        auto& module_metadata = metadata->module[i_module];
+        auto& module_meta = meta->module[i_module];
 
-        size_t diff_to_max = max_pulse_id - module_metadata.pulse_id;
+        size_t diff_to_max = max_pulse_id - module_meta.pulse_id;
         for (size_t i = 0; i < diff_to_max; i++) {
             recv_single_module(
                     sockets[i_module],
-                    &module_metadata,
+                    &module_meta,
                     data + (MODULE_N_BYTES * i_module));
         }
 
-        if (module_metadata.pulse_id != max_pulse_id) {
+        if (module_meta.pulse_id != max_pulse_id) {
             throw runtime_error("Cannot align pulse_ids.");
         }
     }
 
-    return max_pulse_id;
+    return max_pulse_id - min_pulse_id;
 }
 
 void LiveRecvModule::receive_thread()
@@ -160,12 +161,12 @@ void LiveRecvModule::receive_thread()
             }
 
             if (sync_needed) {
-                auto start_time = chrono::steady_clock::now();
+                auto start_time = steady_clock::now();
 
                 auto lost_pulses = align_modules(sockets, metadata, data);
 
-                auto end_time = chrono::steady_clock::now();
-                auto us_duration = chrono::duration_cast<chrono::microseconds>(
+                auto end_time = steady_clock::now();
+                auto us_duration = duration_cast<microseconds>(
                         end_time-start_time).count();
 
                 cout << "sf_stream:sync_lost_pulses " << lost_pulses;