diff --git a/Inc/mmr_can.h b/Inc/mmr_can.h
index 0544c05..75b7499 100644
--- a/Inc/mmr_can.h
+++ b/Inc/mmr_can.h
@@ -8,6 +8,7 @@
 #include "mmr_can_types.h"
 #include "mmr_can_optimize.h"
 #include "mmr_can_binary_literals.h"
+#include "mmr_can_timer_scs.h"
 
 #ifndef MMR_CAN_RX_FIFO
 #define MMR_CAN_RX_FIFO CAN_RX_FIFO0
diff --git a/Inc/mmr_can_timer_scs.h b/Inc/mmr_can_timer_scs.h
new file mode 100644
index 0000000..6a13ba9
--- /dev/null
+++ b/Inc/mmr_can_timer_scs.h
@@ -0,0 +1,60 @@
+#ifndef INC_MMR_CAN_TIMER_SCS_H_
+#define INC_MMR_CAN_TIMER_SCS_H_
+
+#include "mmr_can_message_id.h"
+#include "mmr_can_types.h"
+
+
+/**
+ * Scs_timer represents the max number of counter
+ * that need to checked w/current time
+ */
+#ifndef MMR_SCS_NR_TIMERS
+#define MMR_SCS_NR_TIMERS 5
+#endif
+
+/**
+ * It depends on how many bits the board devotes to the timer
+ * Check the datasheet
+ */
+typedef uint32_t TimerRange;
+
+
+
+typedef struct {
+  MmrCanMessageId scsId;
+  CanId receiverId;
+  TimerRange counter;
+} MmrTimerSCS;
+
+
+/**
+ * @brief Represents the base-struct to manage a single RTR
+ * and allows to interface with the associated SCS's timer
+ */
+typedef struct {
+  MmrCanMessageId scsId;
+  CanId receiverId;
+  int rtr;
+} RTRresponse;
+
+
+
+/**
+ * All time units are to be considered as microseconds ( 1ms )
+ */
+bool MMR_CAN_ClearTimerSCS(MmrCanMessageId scsId, CanId receiverId);
+bool MMR_CAN_SetTimerSCS(MmrCanMessageId scsId, CanId receiverId, TimerRange currentTime);
+
+/**
+ * @brief The delay is taken individually so that the 'manager' 
+ * can first check the ACK and eventually reset the associated arr_timer
+ * 
+ * @param rtrResponse the 'manager' will have to manage an array of struct RTRresponse
+ * @param currentTime from __HAL_TIM_GET_COUNTER(&htimX) or directly from the CNT register
+ * @param thresholdDelay by rules 500ms
+ */
+bool MMR_CAN_GetTimerSCS(RTRresponse *rtrResponse, TimerRange currentTime, TimerRange thresholdDelay);
+
+
+#endif // !INC_MMR_CAN_TIMER_SCS_H_
\ No newline at end of file
diff --git a/Src/mmr_can_timer_scs.c b/Src/mmr_can_timer_scs.c
new file mode 100644
index 0000000..6331b5b
--- /dev/null
+++ b/Src/mmr_can_timer_scs.c
@@ -0,0 +1,72 @@
+#include "mmr_can.h"
+
+static MmrTimerSCS arr_timer[MMR_SCS_NR_TIMERS] = {};
+
+static MmrTimerSCS* findTimer(MmrCanMessageId scsId, CanId receiverId);
+
+
+void MMR_CAN_InitTimerSCS() {
+  for (int i = 0; i < MMR_SCS_NR_TIMERS; i++)
+  {
+    arr_timer[i].scsId = 0;
+    arr_timer[i].receiverId = 0;
+    arr_timer[i].counter = 0;
+  }
+}
+
+
+bool MMR_CAN_ClearTimerSCS(MmrCanMessageId scsId, CanId receiverId) {
+  MmrTimerSCS *timer = findTimer(scsId, receiverId);
+  if (timer == NULL) {
+    return false;
+  }
+
+  timer->scsId = 0;
+  timer->receiverId = 0;
+  timer->counter = 0;
+  return true;
+}
+
+
+bool MMR_CAN_SetTimerSCS(MmrCanMessageId scsId, CanId receiverId, TimerRange currentTime) {
+  MmrTimerSCS *timer = findTimer(scsId, receiverId);
+  if (timer == NULL) {
+    return false;
+  }
+
+  timer->scsId = scsId;
+  timer->receiverId = receiverId;
+  timer->counter = currentTime;
+  return true;
+}
+
+
+bool MMR_CAN_GetTimerSCS(RTRresponse *rtrResponse, TimerRange currentTime, TimerRange thresholdDelay) {
+  MmrTimerSCS *timer = findTimer(
+    rtrResponse->scsId,
+    rtrResponse->receiverId
+  );
+
+  if (timer == NULL) {
+    return false;
+  }
+
+  if (currentTime - timer->counter >= thresholdDelay) {
+    rtrResponse->rtr++;
+  }
+  return true;
+}
+
+
+MmrTimerSCS* findTimer(MmrCanMessageId scsId, CanId receiverId) {
+  int i = 0;
+  for (; i < MMR_SCS_NR_TIMERS; i++) {
+    MmrTimerSCS *timer = arr_timer + i;
+
+    if (timer->scsId == scsId && arr_timer->receiverId == receiverId) {
+      return timer;
+    }
+  }
+
+  return NULL;
+}