diff --git a/datahub/data.py b/datahub/data.py
index ea0b2b2..232a18c 100644
--- a/datahub/data.py
+++ b/datahub/data.py
@@ -7,3 +7,15 @@
 opal_df: pd.DataFrame = create_opal_frame()
 dsr_data: list[dict[str, NDArray | str]] = []  # type: ignore[type-arg]
 wesim_data: dict[str, dict] = {}  # type: ignore[type-arg]
+
+model_running: bool = False
+model_resetting: bool = False
+
+
+def reset_data() -> None:
+    """Reset the OPAL and DSR data to their initial (empty) values."""
+    global opal_df
+    global dsr_data
+
+    opal_df = create_opal_frame()
+    dsr_data = []
diff --git a/datahub/main.py b/datahub/main.py
index 49078d3..2364fa6 100644
--- a/datahub/main.py
+++ b/datahub/main.py
@@ -245,3 +245,80 @@ def get_wesim_data() -> dict[str, dict[str, dict]]:  # type: ignore[type-arg]
         dt.wesim_data = get_wesim()
 
     return {"data": dt.wesim_data}
+
+
+@app.post("/set_model_signals")
+def set_model_signals(start: bool) -> str:
+    """POST method function for setting start and stop model signals.
+
+    It has the query parameter:
+    - `start`: A boolean to indicate the model should start running or stop running.
+
+    \f
+
+    Args:
+        start: A bool flag for if the model should start running or stop running.
+            True to start the model, False to stop the model.
+
+    Returns:
+        A confirmation message
+    """  # noqa: D301
+    message = "Start signal received" if start else "Stop signal received"
+    log.info(message)
+    dt.model_running = start
+
+    return message
+
+
+@app.post("/model_ready")
+def signal_model_ready(ready: bool) -> str:
+    """POST method function for indicating when the model has reset and is ready to run.
+
+    It has the query parameter:
+    - `ready`: A boolean to indicate the model has completed setup and is ready.
+
+    \f
+
+    Args:
+        ready: A bool flag for if the model has completed setup and is ready.
+
+    Returns:
+        A confirmation message
+    """  # noqa: D301
+    message = "Ready signal received" if ready else "Not-Ready signal received"
+    log.info(message)
+    dt.model_resetting = not ready
+
+    return message
+
+
+@app.get("/start")
+def get_start_signal() -> bool:
+    """GET method function for getting start model signal.
+
+    It returns a boolean: True for if the model should start running.
+
+    \f
+
+    Returns:
+        A bool flag for if the model should start
+    """  # noqa: D301
+    log.info("Start signal requested")
+
+    return dt.model_running and not dt.model_resetting
+
+
+@app.get("/stop")
+def get_stop_signal() -> bool:
+    """GET method function for getting stop model signal.
+
+    It returns a boolean: True for if the model should stop running.
+
+    \f
+
+    Returns:
+        A bool flag for if the model should stop
+    """  # noqa: D301
+    log.info("Start signal requested")
+
+    return not dt.model_running
diff --git a/datahub/opal.py b/datahub/opal.py
index 4464c85..878b7db 100644
--- a/datahub/opal.py
+++ b/datahub/opal.py
@@ -166,6 +166,6 @@ def get_opal_row(data: dict[str, int | float] | list[int | float]) -> pd.DataFra
     row = pd.DataFrame(
         [data_array], index=[data_index], columns=list(opal_headers.keys())
     )
-    row["Time"] = pd.Timestamp(OPAL_START_DATE) + pd.to_timedelta(row["Time"], unit="S")
+    row["Time"] = pd.Timestamp(OPAL_START_DATE) + pd.to_timedelta(row["Time"], unit="m")
 
     return row
diff --git a/tests/test_dsr_api.py b/tests/test_dsr_api.py
index 057a9f8..768f1d4 100644
--- a/tests/test_dsr_api.py
+++ b/tests/test_dsr_api.py
@@ -12,7 +12,7 @@
 @pytest.fixture(autouse=True)
 def reset_dsr_data():
     """Pytest Fixture for resetting DSR data global variable."""
-    dt.dsr_data = []
+    dt.reset_data()
 
 
 def test_post_dsr_api(dsr_data_path):
diff --git a/tests/test_opal.py b/tests/test_opal.py
index f0deb9c..e483cf9 100644
--- a/tests/test_opal.py
+++ b/tests/test_opal.py
@@ -44,10 +44,10 @@ def test_append_opal_data(opal_data):
 
     # Checks that data appended to Dataframe matches data input.
     data_1["time"] = pd.Timestamp(OPAL_START_DATE) + pd.to_timedelta(
-        data_1["time"], unit="S"
+        data_1["time"], unit="m"
     )
     data_2["time"] = pd.Timestamp(OPAL_START_DATE) + pd.to_timedelta(
-        data_2["time"], unit="S"
+        data_2["time"], unit="m"
     )
 
     assert (df.loc[1] == list(data_1.values())[1:]).all()
@@ -58,7 +58,7 @@ def test_append_opal_data(opal_data):
     assert len(df.index) == 2
 
     data_3["time"] = pd.Timestamp(OPAL_START_DATE) + pd.to_timedelta(
-        data_3["time"], unit="S"
+        data_3["time"], unit="m"
     )
 
     assert (df.loc[2] == list(data_3.values())[1:]).all()
@@ -100,6 +100,6 @@ def test_append_opal_data_array(opal_data_array):
 
     assert df.shape == (1, len(opal_headers))
 
-    data_1[1] = pd.Timestamp(OPAL_START_DATE) + pd.to_timedelta(data_1[1], unit="S")
+    data_1[1] = pd.Timestamp(OPAL_START_DATE) + pd.to_timedelta(data_1[1], unit="m")
 
     assert (df.loc[1] == data_1[1:]).all()
diff --git a/tests/test_opal_api.py b/tests/test_opal_api.py
index 3367e56..e15a26c 100644
--- a/tests/test_opal_api.py
+++ b/tests/test_opal_api.py
@@ -9,9 +9,7 @@
 @pytest.fixture(autouse=True)
 def reset_opal_data():
     """Pytest Fixture for resetting Opal data global variable."""
-    from datahub.opal import create_opal_frame
-
-    dt.opal_df = create_opal_frame()
+    dt.reset_data()
 
 
 def test_post_opal_api(client, opal_data):