diff --git a/settings.json b/settings.json
index b1b8a18..7c2df7d 100644
--- a/settings.json
+++ b/settings.json
@@ -2,7 +2,7 @@
     "general": {
         "scan_limit": 60,
         "max_range": 100,
-        "geometry": "1200x1024+463+195",
+        "geometry": "1200x1024+85+163",
         "last_selected_scenario": "scenario_9g",
         "connection": {
             "target": {
diff --git a/target_simulator/gui/payload_router.py b/target_simulator/gui/payload_router.py
new file mode 100644
index 0000000..200fc8f
--- /dev/null
+++ b/target_simulator/gui/payload_router.py
@@ -0,0 +1,235 @@
+"""Payload router for buffering SFP payloads for the GUI.
+
+This module extracts the DebugPayloadRouter class so the router can be
+reused and tested independently from the Tkinter window.
+"""
+import threading
+import collections
+import datetime
+import os
+import logging
+from typing import Dict, Optional, Any
+from target_simulator.core.sfp_structures import SFPHeader, SfpRisStatusPayload
+
+
+class DebugPayloadRouter:
+    """
+    A router that buffers the last received payload for each flow,
+    allowing the GUI to sample the data at a lower frequency.
+    This class is thread-safe.
+    """
+
+    def __init__(self):
+        self._log_prefix = "[DebugPayloadRouter]"
+        self._lock = threading.Lock()
+        # Buffer to store the last received payload for each flow type
+        self._latest_payloads: Dict[str, bytearray] = {}
+        # Buffer to store the last raw packet received (bytes, addr)
+        self._last_raw_packet: Optional[tuple] = None
+        # History of raw packets (timestamp, addr, raw bytes)
+        self._history_size = 20
+        self._history = collections.deque(maxlen=self._history_size)
+        self._persist = False
+        # default persist dir: repository Temp/ folder
+        project_root = os.path.abspath(
+            os.path.join(os.path.dirname(__file__), "..", "..")
+        )
+        self._persist_dir = os.path.join(project_root, "Temp")
+        try:
+            os.makedirs(self._persist_dir, exist_ok=True)
+        except Exception:
+            pass
+        logging.info(f"{self._log_prefix} Initialized.")
+
+    def get_handlers(self) -> Dict[int, Any]:
+        """Returns handlers that update the internal last-payload buffer."""
+        return {
+            ord("M"): lambda payload: self._update_last_payload("MFD", payload),
+            ord("S"): lambda payload: self._update_last_payload("SAR", payload),
+            ord("B"): lambda payload: self._update_last_payload("BIN", payload),
+            ord("J"): lambda payload: self._update_last_payload("JSON", payload),
+            # Support both uppercase 'R' and lowercase 'r' as RIS/status flows
+            ord("R"): lambda payload: self._handle_ris_status(payload),
+            ord("r"): lambda payload: self._handle_ris_status(payload),
+        }
+
+    def _update_last_payload(self, flow_id: str, payload: bytearray):
+        """Thread-safely stores the latest payload for a given flow."""
+        with self._lock:
+            self._latest_payloads[flow_id] = payload
+
+    def _handle_ris_status(self, payload: bytearray):
+        """Try to parse a RIS status payload and store a concise summary.
+
+        If parsing fails, store the raw payload as before.
+        """
+        try:
+            if len(payload) >= SfpRisStatusPayload.size():
+                # Interpret the first bytes as the status payload
+                parsed = SfpRisStatusPayload.from_buffer_copy(
+                    bytes(payload[: SfpRisStatusPayload.size()])
+                )
+                sc = parsed.scenario
+                lines = []
+                lines.append("RIS Status Payload:\n")
+                # Scenario block
+                lines.append("Scenario:")
+                lines.append(f"  timetag       : {sc.timetag}")
+                lines.append(f"  platform_azim : {sc.platform_azimuth:.6f}")
+                lines.append(f"  vx,vy,vz      : {sc.vx:.3f}, {sc.vy:.3f}, {sc.vz:.3f}")
+                lines.append(f"  baro_altitude : {sc.baro_altitude:.3f}")
+                lines.append(f"  latitude      : {sc.latitude:.6f}")
+                lines.append(f"  longitude     : {sc.longitude:.6f}")
+                lines.append(f"  true_heading  : {sc.true_heading:.3f}\n")
+
+                # Targets block
+                lines.append("Targets (first non-zero flags shown):")
+                any_target = False
+                for idx, t in enumerate(parsed.tgt.tgt):
+                    if t.flags != 0:
+                        any_target = True
+                        lines.append(
+                            f"  [{idx}] flags={t.flags} heading={t.heading:.3f} x={t.x:.3f} y={t.y:.3f} z={t.z:.3f}"
+                        )
+                if not any_target:
+                    lines.append("  (no enabled targets)")
+
+                # NOTE: omit hex sample from RIS textual summary to avoid
+                # cluttering the application log with large binary dumps.
+                # The structured JSON payload (RIS_STATUS_JSON) contains
+                # the parsed values that the UI consumes.
+
+                text_out = "\n".join(lines)
+                # Build structured JSON for UI table consumption
+                try:
+                    import json
+
+                    scenario_dict = {
+                        "timetag": int(parsed.scenario.timetag),
+                        "platform_azimuth": float(parsed.scenario.platform_azimuth),
+                        "vx": float(parsed.scenario.vx),
+                        "vy": float(parsed.scenario.vy),
+                        "vz": float(parsed.scenario.vz),
+                        "baro_altitude": float(parsed.scenario.baro_altitude),
+                        "latitude": float(parsed.scenario.latitude),
+                        "longitude": float(parsed.scenario.longitude),
+                        "true_heading": float(parsed.scenario.true_heading),
+                    }
+                    targets_list = []
+                    for idx, t in enumerate(parsed.tgt.tgt):
+                        targets_list.append(
+                            {
+                                "index": idx,
+                                "flags": int(t.flags),
+                                "heading": float(t.heading),
+                                "x": float(t.x),
+                                "y": float(t.y),
+                                "z": float(t.z),
+                            }
+                        )
+                    struct = {"scenario": scenario_dict, "targets": targets_list}
+                    json_bytes = bytearray(json.dumps(struct).encode("utf-8"))
+                except Exception:
+                    json_bytes = bytearray(b"{}")
+
+                # Store textual representation and structured JSON so GUI can display it directly
+                self._update_last_payload("RIS_STATUS", bytearray(text_out.encode("utf-8")))
+                self._update_last_payload("RIS_STATUS_JSON", json_bytes)
+                return
+        except Exception:
+            # fall through to storing raw payload
+            pass
+
+        # Fallback: store raw payload (as hex dump)
+        try:
+            text_out = "\n".join([f"{b:02X}" for b in payload])
+            self._update_last_payload("RIS_STATUS", bytearray(text_out.encode("utf-8")))
+        except Exception:
+            self._update_last_payload("RIS_STATUS", payload)
+
+    def get_and_clear_latest_payloads(self) -> Dict[str, bytearray]:
+        """
+        Thread-safely retrieves all new payloads received since the last call
+        and clears the internal buffer.
+
+        Returns:
+            Dict[str, bytearray]: A dictionary of the latest payload for each flow.
+        """
+        with self._lock:
+            # Atomically swap the buffer with an empty one
+            new_payloads = self._latest_payloads
+            self._latest_payloads = {}
+            return new_payloads
+
+    def update_raw_packet(self, raw_bytes: bytes, addr: tuple):
+        """Store the last raw packet received (overwritten by subsequent packets)."""
+        with self._lock:
+            # Keep last packet for immediate display
+            self._last_raw_packet = (raw_bytes, addr)
+            # Append to history with timestamp and small metadata
+            entry = {
+                "ts": datetime.datetime.utcnow(),
+                "addr": addr,
+                "raw": raw_bytes,
+            }
+            # Try to parse SFP header to capture flow/TID for list display
+            try:
+                hdr = SFPHeader.from_buffer_copy(raw_bytes)
+                entry["flow"] = int(hdr.SFP_FLOW)
+                entry["tid"] = int(hdr.SFP_TID)
+                # map common flows to names when possible
+                flow_map = {
+                    ord("M"): "MFD",
+                    ord("S"): "SAR",
+                    ord("B"): "BIN",
+                    ord("J"): "JSON",
+                }
+                entry["flow_name"] = flow_map.get(
+                    entry["flow"],
+                    (
+                        chr(entry["flow"]) if 32 <= entry["flow"] < 127 else str(entry["flow"])
+                    ),
+                )
+            except Exception:
+                # best-effort: leave flow/tid absent
+                pass
+            self._history.append(entry)
+            # Optionally persist to disk (each entry as binary)
+            if self._persist:
+                try:
+                    ts = entry["ts"].strftime("%Y%m%dT%H%M%S.%f")
+                    fname = f"sfp_raw_{ts}_{addr[0].replace(':','_')}_{addr[1]}.bin"
+                    path = os.path.join(self._persist_dir, fname)
+                    with open(path, "wb") as f:
+                        f.write(raw_bytes)
+                except Exception:
+                    # don't propagate persistence errors to caller
+                    pass
+
+    def get_and_clear_raw_packet(self) -> Optional[tuple]:
+        with self._lock:
+            pkt = self._last_raw_packet
+            self._last_raw_packet = None
+            return pkt
+
+    def get_history(self):
+        with self._lock:
+            return list(self._history)
+
+    def clear_history(self):
+        with self._lock:
+            self._history.clear()
+
+    def set_history_size(self, n: int):
+        with self._lock:
+            try:
+                n = max(1, int(n))
+            except Exception:
+                return
+            self._history_size = n
+            new_deque = collections.deque(self._history, maxlen=self._history_size)
+            self._history = new_deque
+
+    def set_persist(self, enabled: bool):
+        with self._lock:
+            self._persist = bool(enabled)
diff --git a/target_simulator/gui/sfp_debug_window.py b/target_simulator/gui/sfp_debug_window.py
index f8b5011..8cbd461 100644
--- a/target_simulator/gui/sfp_debug_window.py
+++ b/target_simulator/gui/sfp_debug_window.py
@@ -34,329 +34,63 @@ from target_simulator.core.sfp_structures import (
     SFPHeader,
     SfpRisStatusPayload,
 )
-
-# --- Helper Class for Routing and Buffering Payloads ---
-
-
-class DebugPayloadRouter:
-    """
-    A router that buffers the last received payload for each flow,
-    allowing the GUI to sample the data at a lower frequency.
-    This class is thread-safe.
-    """
-
-    def __init__(self):
-        self._log_prefix = "[DebugPayloadRouter]"
-        self._lock = threading.Lock()
-        # Buffer to store the last received payload for each flow type
-        self._latest_payloads: Dict[str, bytearray] = {}
-        # Buffer to store the last raw packet received (bytes, addr)
-        self._last_raw_packet: Optional[tuple] = None
-        # History of raw packets (timestamp, addr, raw bytes)
-        self._history_size = 20
-        self._history = collections.deque(maxlen=self._history_size)
-        self._persist = False
-        # default persist dir: repository Temp/ folder
-        project_root = os.path.abspath(
-            os.path.join(os.path.dirname(__file__), "..", "..")
-        )
-        self._persist_dir = os.path.join(project_root, "Temp")
-        try:
-            os.makedirs(self._persist_dir, exist_ok=True)
-        except Exception:
-            pass
-        logging.info(f"{self._log_prefix} Initialized.")
-
-    def get_handlers(self) -> Dict[int, PayloadHandler]:
-        """Returns handlers that update the internal last-payload buffer."""
-        return {
-            ord("M"): lambda payload: self._update_last_payload("MFD", payload),
-            ord("S"): lambda payload: self._update_last_payload("SAR", payload),
-            ord("B"): lambda payload: self._update_last_payload("BIN", payload),
-            ord("J"): lambda payload: self._update_last_payload("JSON", payload),
-            # Support both uppercase 'R' and lowercase 'r' as RIS/status flows
-            ord("R"): lambda payload: self._handle_ris_status(payload),
-            ord("r"): lambda payload: self._handle_ris_status(payload),
-        }
-
-    def _update_last_payload(self, flow_id: str, payload: bytearray):
-        """Thread-safely stores the latest payload for a given flow."""
-        with self._lock:
-            self._latest_payloads[flow_id] = payload
-
-    def _handle_ris_status(self, payload: bytearray):
-        """Try to parse a RIS status payload and store a concise summary.
-
-        If parsing fails, store the raw payload as before.
-        """
-        try:
-            if len(payload) >= SfpRisStatusPayload.size():
-                # Interpret the first bytes as the status payload
-                parsed = SfpRisStatusPayload.from_buffer_copy(
-                    bytes(payload[: SfpRisStatusPayload.size()])
-                )
-                sc = parsed.scenario
-                lines = []
-                lines.append("RIS Status Payload:\n")
-                # Scenario block
-                lines.append("Scenario:")
-                lines.append(f"  timetag       : {sc.timetag}")
-                lines.append(f"  platform_azim : {sc.platform_azimuth:.6f}")
-                lines.append(f"  vx,vy,vz      : {sc.vx:.3f}, {sc.vy:.3f}, {sc.vz:.3f}")
-                lines.append(f"  baro_altitude : {sc.baro_altitude:.3f}")
-                lines.append(f"  latitude      : {sc.latitude:.6f}")
-                lines.append(f"  longitude     : {sc.longitude:.6f}")
-                lines.append(f"  true_heading  : {sc.true_heading:.3f}\n")
-
-                # Targets block
-                lines.append("Targets (first non-zero flags shown):")
-                any_target = False
-                for idx, t in enumerate(parsed.tgt.tgt):
-                    if t.flags != 0:
-                        any_target = True
-                        lines.append(
-                            f"  [{idx}] flags={t.flags} heading={t.heading:.3f} x={t.x:.3f} y={t.y:.3f} z={t.z:.3f}"
-                        )
-                if not any_target:
-                    lines.append("  (no enabled targets)")
-
-                # Attach a short hex summary of the first bytes after the header so user can correlate
-                try:
-                    sample_len = min(48, len(payload))
-                    sample = payload[:sample_len]
-                    hex_sample = " ".join(f"{b:02X}" for b in sample)
-                    lines.append("\nPayload sample (hex, first %d bytes):" % sample_len)
-                    lines.append(f"  {hex_sample}")
-                except Exception:
-                    pass
-
-                text_out = "\n".join(lines)
-                # Build structured JSON for UI table consumption
-                try:
-                    import json
-
-                    scenario_dict = {
-                        "timetag": int(parsed.scenario.timetag),
-                        "platform_azimuth": float(parsed.scenario.platform_azimuth),
-                        "vx": float(parsed.scenario.vx),
-                        "vy": float(parsed.scenario.vy),
-                        "vz": float(parsed.scenario.vz),
-                        "baro_altitude": float(parsed.scenario.baro_altitude),
-                        "latitude": float(parsed.scenario.latitude),
-                        "longitude": float(parsed.scenario.longitude),
-                        "true_heading": float(parsed.scenario.true_heading),
-                    }
-                    targets_list = []
-                    for idx, t in enumerate(parsed.tgt.tgt):
-                        targets_list.append(
-                            {
-                                "index": idx,
-                                "flags": int(t.flags),
-                                "heading": float(t.heading),
-                                "x": float(t.x),
-                                "y": float(t.y),
-                                "z": float(t.z),
-                            }
-                        )
-                    struct = {"scenario": scenario_dict, "targets": targets_list}
-                    json_bytes = bytearray(json.dumps(struct).encode("utf-8"))
-                except Exception:
-                    json_bytes = bytearray(b"{}")
-
-                # Store textual representation and structured JSON so GUI can display it directly
-                self._update_last_payload("RIS_STATUS", bytearray(text_out.encode("utf-8")))
-                self._update_last_payload("RIS_STATUS_JSON", json_bytes)
-                return
-        except Exception:
-            # fall through to storing raw payload
-            pass
-
-        # Fallback: store raw payload (as hex dump)
-        try:
-            text_out = "\n".join([f"{b:02X}" for b in payload])
-            self._update_last_payload("RIS_STATUS", bytearray(text_out.encode("utf-8")))
-        except Exception:
-            self._update_last_payload("RIS_STATUS", payload)
-
-    def get_and_clear_latest_payloads(self) -> Dict[str, bytearray]:
-        """
-        Thread-safely retrieves all new payloads received since the last call
-        and clears the internal buffer.
-
-        Returns:
-            Dict[str, bytearray]: A dictionary of the latest payload for each flow.
-        """
-        with self._lock:
-            # Atomically swap the buffer with an empty one
-            new_payloads = self._latest_payloads
-            self._latest_payloads = {}
-            return new_payloads
-
-    def update_raw_packet(self, raw_bytes: bytes, addr: tuple):
-        """Store the last raw packet received (overwritten by subsequent packets)."""
-        with self._lock:
-            # Keep last packet for immediate display
-            self._last_raw_packet = (raw_bytes, addr)
-            # Append to history with timestamp and small metadata
-            entry = {
-                "ts": datetime.datetime.utcnow(),
-                "addr": addr,
-                "raw": raw_bytes,
-            }
-            # Try to parse SFP header to capture flow/TID for list display
-            try:
-                hdr = SFPHeader.from_buffer_copy(raw_bytes)
-                entry["flow"] = int(hdr.SFP_FLOW)
-                entry["tid"] = int(hdr.SFP_TID)
-                # map common flows to names when possible
-                flow_map = {
-                    ord("M"): "MFD",
-                    ord("S"): "SAR",
-                    ord("B"): "BIN",
-                    ord("J"): "JSON",
-                }
-                entry["flow_name"] = flow_map.get(
-                    entry["flow"],
-                    (
-                        chr(entry["flow"])
-                        if 32 <= entry["flow"] < 127
-                        else str(entry["flow"])
-                    ),
-                )
-            except Exception:
-                # best-effort: leave flow/tid absent
-                pass
-            self._history.append(entry)
-            # Optionally persist to disk (each entry as binary)
-            if self._persist:
-                try:
-                    ts = entry["ts"].strftime("%Y%m%dT%H%M%S.%f")
-                    fname = f"sfp_raw_{ts}_{addr[0].replace(':','_')}_{addr[1]}.bin"
-                    path = os.path.join(self._persist_dir, fname)
-                    with open(path, "wb") as f:
-                        f.write(raw_bytes)
-                except Exception:
-                    # don't propagate persistence errors to caller
-                    pass
-
-    def get_and_clear_raw_packet(self) -> Optional[tuple]:
-        with self._lock:
-            pkt = self._last_raw_packet
-            self._last_raw_packet = None
-            return pkt
-
-    def get_history(self):
-        with self._lock:
-            return list(self._history)
-
-    def clear_history(self):
-        with self._lock:
-            self._history.clear()
-
-    def set_history_size(self, n: int):
-        with self._lock:
-            try:
-                n = max(1, int(n))
-            except Exception:
-                return
-            self._history_size = n
-            new_deque = collections.deque(self._history, maxlen=self._history_size)
-            self._history = new_deque
-
-    def set_persist(self, enabled: bool):
-        with self._lock:
-            self._persist = bool(enabled)
-
-
-# --- Main Debug Window Class ---
+from target_simulator.gui.payload_router import DebugPayloadRouter
 
 
 class SfpDebugWindow(tk.Toplevel):
-    """A self-contained SFP debugging and packet inspection window."""
+    """Top-level window for SFP debugging and payload inspection.
 
-    GUI_POLL_INTERVAL_MS = 250  # Poll for new data 4 times per second
+    This class was previously defining the DebugPayloadRouter inline; the
+    router implementation has been moved to `target_simulator.gui.payload_router`
+    to decouple routing logic from the Tk window and allow independent tests.
+    """
 
-    def __init__(self, master):
+    GUI_POLL_INTERVAL_MS = 250
+
+    def __init__(self, master=None):
         super().__init__(master)
-        self.title("SFP Packet Inspector")
-        self.geometry("900x700")
-        self.transient(master)
-
+        self.master = master
         self.logger = logging.getLogger(__name__)
-        self.sfp_transport: Optional[SfpTransport] = None
+        # Router instance (buffers latest payloads per flow)
         self.payload_router = DebugPayloadRouter()
+        # Transport reference (set when connecting)
+        self.sfp_transport = None
+        # Image display defaults
+        self.image_area_size = 150
+        # Connection fields
+        self.ip_var = tk.StringVar(value="127.0.0.1")
+        self.port_var = tk.StringVar(value="60002")
 
-        # Try to apply saved debug settings (history size, persist) from ConfigManager
+        # --- Connection Frame (IP / Port / Connect controls) ---
+        conn_frame = ttk.Frame(self)
+        conn_frame.pack(side=tk.TOP, fill=tk.X, padx=5, pady=(5, 2))
+
+        ttk.Label(conn_frame, text="IP:").pack(side=tk.LEFT, padx=(4, 2))
+        ttk.Entry(conn_frame, textvariable=self.ip_var, width=18).pack(
+            side=tk.LEFT, padx=(0, 6)
+        )
+        ttk.Label(conn_frame, text="Port:").pack(side=tk.LEFT, padx=(0, 2))
+        ttk.Entry(conn_frame, textvariable=self.port_var, width=8).pack(
+            side=tk.LEFT, padx=(0, 6)
+        )
+
+        self.connect_btn = ttk.Button(conn_frame, text="Connect", command=self._on_connect)
+        self.connect_btn.pack(side=tk.LEFT, padx=(0, 6))
+        self.disconnect_btn = ttk.Button(conn_frame, text="Disconnect", command=self._on_disconnect)
+        self.disconnect_btn.pack(side=tk.LEFT, padx=(0, 6))
+        # Start with disconnect disabled until connected
         try:
-            gm = getattr(master, "config_manager", None)
-            general = gm.get_general_settings() if gm else {}
-            sfp_debug_conf = general.get("sfp_debug", {})
-            hist_size = int(sfp_debug_conf.get("history_size", 20))
-            persist_raw = bool(sfp_debug_conf.get("persist_raw", False))
-            # apply to router
-            try:
-                self.payload_router.set_history_size(hist_size)
-                self.payload_router.set_persist(persist_raw)
-            except Exception:
-                pass
+            self.disconnect_btn.config(state=tk.DISABLED)
         except Exception:
             pass
 
-        self.mfd_photo: Optional[ImageTk.PhotoImage] = None
-        self.sar_photo: Optional[ImageTk.PhotoImage] = None
+        # Quick utility buttons
+        self.send_probe_btn = ttk.Button(conn_frame, text="Send probe", command=self._on_send_probe)
+        self.send_probe_btn.pack(side=tk.LEFT, padx=(6, 4))
+        self.send_ack_btn = ttk.Button(conn_frame, text="Send ACK", command=self._on_send_ack)
+        self.send_ack_btn.pack(side=tk.LEFT)
 
-        # Read image display size from settings (general.image_display.size)
-        try:
-            gm = getattr(master, "config_manager", None)
-            general = gm.get_general_settings() if gm else {}
-            img_conf = general.get("image_display", {})
-            self.image_area_size = int(img_conf.get("size", 150))
-        except Exception:
-            self.image_area_size = 150
-
-        self._create_widgets()
-        self.protocol("WM_DELETE_WINDOW", self._on_close)
-
-        self.after(self.GUI_POLL_INTERVAL_MS, self._process_latest_payloads)
-        # Track last raw update time to throttle high-volume flows
-        self._last_raw_update_ts = 0.0
-
-    def _create_widgets(self):
-        # --- Connection Controls (unchanged) ---
-        conn_frame = ttk.LabelFrame(self, text="Connection", padding=5)
-        conn_frame.pack(side=tk.TOP, fill=tk.X, padx=5, pady=5)
-        ttk.Label(conn_frame, text="IP:").pack(side=tk.LEFT, padx=(5, 2))
-        self.ip_var = tk.StringVar(value="127.0.0.1")
-        ttk.Entry(conn_frame, textvariable=self.ip_var, width=15).pack(side=tk.LEFT)
-        ttk.Label(conn_frame, text="Port:").pack(side=tk.LEFT, padx=(10, 2))
-        self.port_var = tk.StringVar(value="60002") ##55556 per mfd
-        ttk.Entry(conn_frame, textvariable=self.port_var, width=7).pack(side=tk.LEFT)
-        self.connect_btn = ttk.Button(
-            conn_frame, text="Connect", command=self._on_connect
-        )
-        self.connect_btn.pack(side=tk.LEFT, padx=(10, 5))
-        self.disconnect_btn = ttk.Button(
-            conn_frame,
-            text="Disconnect",
-            command=self._on_disconnect,
-            state=tk.DISABLED,
-        )
-        self.disconnect_btn.pack(side=tk.LEFT, padx=5)
-        # Button to configure image display size
-        self.image_size_btn = ttk.Button(
-            conn_frame, text="Image size...", command=self._open_image_size_dialog
-        )
-        self.image_size_btn.pack(side=tk.LEFT, padx=5)
-        # Button to send a simple UDP probe to the configured IP:Port
-        self.send_probe_btn = ttk.Button(
-            conn_frame, text="Send probe", command=self._on_send_probe
-        )
-        self.send_probe_btn.pack(side=tk.LEFT, padx=5)
-        # Button to send a minimal SFP ACK packet to the configured IP:Port
-        self.send_ack_btn = ttk.Button(
-            conn_frame, text="Send ACK", command=self._on_send_ack
-        )
-        self.send_ack_btn.pack(side=tk.LEFT, padx=5)
+        # Note: DebugPayloadRouter has been moved to `target_simulator.gui.payload_router`.
 
         # --- Script Sender Frame (below connection) ---
         script_frame = ttk.Frame(self)
@@ -383,11 +117,49 @@ class SfpDebugWindow(tk.Toplevel):
             self.notebook.add(self.mfd_tab["frame"], text="MFD Image")
             self.sar_tab = self._create_image_tab("SAR Image")
             self.notebook.add(self.sar_tab["frame"], text="SAR Image")
-        # RIS status tab: textual decoded status of RIS payloads
-        self.ris_tab = scrolledtext.ScrolledText(
-            self.notebook, state=tk.DISABLED, wrap=tk.WORD, font=("Consolas", 10)
-        )
-        self.notebook.add(self.ris_tab, text="RIS Status")
+        # RIS status tab: two-column layout with scenario (left) and targets (right)
+        ris_frame = ttk.Frame(self.notebook)
+        paned = ttk.Panedwindow(ris_frame, orient=tk.HORIZONTAL)
+        paned.pack(fill=tk.BOTH, expand=True, padx=5, pady=5)
+
+        # Left: scenario table (field, value)
+        left = ttk.Frame(paned)
+        self.scenario_tree = ttk.Treeview(left, columns=("field", "value"), show="headings", height=12)
+        self.scenario_tree.heading("field", text="Field")
+        self.scenario_tree.heading("value", text="Value")
+        self.scenario_tree.column("field", width=140, anchor="w")
+        self.scenario_tree.column("value", width=160, anchor="w")
+        self.scenario_tree.pack(fill=tk.BOTH, expand=True)
+        paned.add(left, weight=1)
+
+        # Right: compact targets table
+        right = ttk.Frame(paned)
+        cols = ("idx", "flags", "heading", "x", "y", "z")
+        self.ris_tree = ttk.Treeview(right, columns=cols, show="headings", height=12)
+        for c, txt in zip(cols, ("#", "flags", "heading", "x", "y", "z")):
+            self.ris_tree.heading(c, text=txt)
+            self.ris_tree.column(c, width=70, anchor="center")
+
+        # Apply smaller font to make table compact
+        try:
+            style = ttk.Style()
+            small_font = ("Consolas", 8)
+            style.configure("Small.Treeview", font=small_font)
+            self.ris_tree.configure(style="Small.Treeview")
+            self.scenario_tree.configure(style="Small.Treeview")
+        except Exception:
+            pass
+
+        self.ris_tree.pack(fill=tk.BOTH, expand=True)
+        paned.add(right, weight=2)
+
+        # Save CSV button under the paned window
+        btn_frame = ttk.Frame(ris_frame)
+        btn_frame.pack(fill=tk.X, padx=5, pady=(0, 5))
+        self.ris_save_csv_btn = ttk.Button(btn_frame, text="Save CSV", command=lambda: self._on_save_ris_csv())
+        self.ris_save_csv_btn.pack(side=tk.RIGHT)
+
+        self.notebook.add(ris_frame, text="RIS Status")
         # Raw SFP packet view with history on the left and details on the right
         raw_frame = ttk.Frame(self.notebook)
         # Left: history listbox
@@ -479,6 +251,13 @@ class SfpDebugWindow(tk.Toplevel):
         )
         self.notebook.add(self.json_tab, text="JSON")
 
+        # Start the periodic GUI poll loop to process latest payloads from the router
+        try:
+            self.after(self.GUI_POLL_INTERVAL_MS, self._process_latest_payloads)
+        except Exception:
+            # If the Tk mainloop isn't running in tests, this will be a no-op
+            pass
+
     def _create_image_tab(self, title: str) -> Dict:
         frame = ttk.Frame(self.notebook)
         # Fixed-size container to keep UI tidy. Image area will be size x size px.
@@ -572,6 +351,7 @@ class SfpDebugWindow(tk.Toplevel):
             port=port,
             payload_handlers=self.payload_router.get_handlers(),
             ack_config=ack_config,
+            raw_packet_callback=self.payload_router.update_raw_packet,
         )
         if self.sfp_transport.start():
             self._log_to_widget(
@@ -583,18 +363,6 @@ class SfpDebugWindow(tk.Toplevel):
             self._log_to_widget("Connection failed. Check IP/Port and logs.", "ERROR")
             self.sfp_transport = None
         # Register raw packet callback regardless of start result (safe no-op if None)
-        if self.sfp_transport:
-            # Provide the router.update_raw_packet method as callback
-            try:
-                self.sfp_transport._raw_packet_callback = (
-                    self.payload_router.update_raw_packet
-                )
-            except Exception:
-                self.logger.exception(
-                    "Failed to register raw_packet_callback on SfpTransport"
-                )
-
-        # Bind history tree selection to show past packet
         try:
             self.history_tree.bind(
                 "<<TreeviewSelect>>", lambda e: self._on_history_select()
@@ -806,21 +574,56 @@ class SfpDebugWindow(tk.Toplevel):
                 elif flow_id == "JSON":
                     self._display_json_data(payload, self.json_tab)
                 elif flow_id == "RIS_STATUS":
-                    # Display the textual RIS status in the RIS tab
+                    # textual fallback: we intentionally do not write the
+                    # full RIS textual summary into the generic log to avoid
+                    # clutter; the structured JSON payload is used for UI.
+                    # Keep this branch present in case future handling is
+                    # needed.
+                    pass
+                elif flow_id == "RIS_STATUS_JSON":
+                    # Populate the scenario tree and the RIS targets tree from structured JSON
                     try:
-                        text = (
-                            payload.decode("utf-8")
-                            if isinstance(payload, (bytes, bytearray))
-                            else str(payload)
-                        )
+                        import json
+
+                        struct = json.loads(payload.decode("utf-8")) if isinstance(payload, (bytes, bytearray)) else payload
+                        # scenario table (field, value)
+                        for iid in self.scenario_tree.get_children():
+                            self.scenario_tree.delete(iid)
+                        scenario = struct.get("scenario", {}) if isinstance(struct, dict) else {}
+                        if scenario:
+                            # Insert in deterministic order
+                            order = [
+                                ("timetag", "timetag"),
+                                ("platform_azimuth", "platform_azimuth"),
+                                ("vx", "vx"),
+                                ("vy", "vy"),
+                                ("vz", "vz"),
+                                ("baro_altitude", "baro_altitude"),
+                                ("latitude", "latitude"),
+                                ("longitude", "longitude"),
+                                ("true_heading", "true_heading"),
+                            ]
+                            for label, key in order:
+                                if key in scenario:
+                                    self.scenario_tree.insert("", tk.END, values=(label, scenario.get(key)))
+
+                        # targets
+                        for iid in self.ris_tree.get_children():
+                            self.ris_tree.delete(iid)
+                        targets = struct.get("targets", []) if isinstance(struct, dict) else []
+                        for t in targets:
+                            vals = (
+                                t.get("index"),
+                                t.get("flags"),
+                                f"{t.get('heading'):.3f}",
+                                f"{t.get('x'):.3f}",
+                                f"{t.get('y'):.3f}",
+                                f"{t.get('z'):.3f}",
+                            )
+                            self.ris_tree.insert("", tk.END, values=vals)
                     except Exception:
-                        text = str(payload)
-                    self.ris_tab.config(state=tk.NORMAL)
-                    self.ris_tab.delete("1.0", tk.END)
-                    self.ris_tab.insert("1.0", text)
-                    self.ris_tab.config(state=tk.DISABLED)
-                    # Optionally show the RIS tab automatically
-                    # self.notebook.select(self.ris_tab)
+                        # ignore malformed JSON for now
+                        pass
                     # self.notebook.select(self.json_tab)
 
         # Reschedule the next check
@@ -1248,6 +1051,45 @@ class SfpDebugWindow(tk.Toplevel):
         self.log_tab.config(state=tk.DISABLED)
         self.log_tab.see(tk.END)
 
+    def _on_save_ris_csv(self):
+        try:
+            import csv
+
+            # collect rows from tree
+
+            # collect scenario rows
+            scenario_rows = [self.scenario_tree.item(iid, "values") for iid in self.scenario_tree.get_children()]
+            # collect target rows
+            rows = [self.ris_tree.item(iid, "values") for iid in self.ris_tree.get_children()]
+
+            if not scenario_rows and not rows:
+                self._log_to_widget("No RIS data to save.", "INFO")
+                return
+
+            # ensure Temp dir exists
+            project_root = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
+            temp_dir = os.path.join(project_root, "Temp")
+            os.makedirs(temp_dir, exist_ok=True)
+            ts = datetime.datetime.utcnow().strftime("%Y%m%dT%H%M%S")
+            fname = f"ris_targets_{ts}.csv"
+            path = os.path.join(temp_dir, fname)
+            with open(path, "w", newline="", encoding="utf-8") as f:
+                writer = csv.writer(f)
+                # write scenario fields first
+                if scenario_rows:
+                    writer.writerow(["Scenario Field", "Value"])
+                    for s in scenario_rows:
+                        writer.writerow(s)
+                    writer.writerow([])
+                # write targets
+                writer.writerow(["index", "flags", "heading", "x", "y", "z"])
+                for r in rows:
+                    writer.writerow(r)
+
+            self._log_to_widget(f"Saved RIS targets CSV to {path}", "INFO")
+        except Exception as e:
+            self._log_to_widget(f"Failed to save RIS CSV: {e}", "ERROR")
+
     def _format_hex_dump(self, data: bytes, length=16) -> str:
         lines = []
         for i in range(0, len(data), length):
diff --git a/tests/core/test_ris_parsing.py b/tests/core/test_ris_parsing.py
new file mode 100644
index 0000000..70b28f2
--- /dev/null
+++ b/tests/core/test_ris_parsing.py
@@ -0,0 +1,52 @@
+import json
+import ctypes
+
+from target_simulator.core.sfp_structures import (
+    SfpRisStatusPayload,
+    RisScenario,
+    RisTarget,
+    RisTargetsBlock,
+    DSP_RIS_MAX_TGT,
+)
+from target_simulator.gui.sfp_debug_window import DebugPayloadRouter
+
+
+def build_test_payload():
+    # build a minimal payload with scenario + one target enabled
+    payload = SfpRisStatusPayload()
+    # fill scenario
+    payload.scenario.timetag = 123456
+    payload.scenario.platform_azimuth = 1.23
+    payload.scenario.vx = 10.0
+    payload.scenario.vy = -2.5
+    payload.scenario.vz = 0.0
+    payload.scenario.baro_altitude = 100.0
+    payload.scenario.true_heading = 45.0
+    payload.scenario.latitude = 12.345678
+    payload.scenario.longitude = 98.765432
+
+    # fill first target
+    payload.tgt.tgt[0].flags = 1
+    payload.tgt.tgt[0].heading = 90.0
+    payload.tgt.tgt[0].x = 1.0
+    payload.tgt.tgt[0].y = 2.0
+    payload.tgt.tgt[0].z = 3.0
+
+    return bytes(payload)
+
+
+def test_ris_router_parsing():
+    router = DebugPayloadRouter()
+    data = build_test_payload()
+    # call handler directly
+    router._handle_ris_status(bytearray(data))
+    # retrieve latest payloads
+    latest = router.get_and_clear_latest_payloads()
+    # Expect RIS_STATUS textual summary or raw
+    assert "RIS_STATUS" in latest
+    # textual content should include timetag and heading
+    txt = latest["RIS_STATUS"].decode("utf-8")
+    assert "timetag" in txt.lower() or "timetag" in txt
+
+    # Note: _handle_ris_status also stores RIS_STATUS as text; JSON variant stored by SfpDebugWindow logic
+    # If JSON is not present in router (router stores only last payload per key) we at least ensure textual parse exists
diff --git a/tests/gui/test_sfp_debug_polling.py b/tests/gui/test_sfp_debug_polling.py
new file mode 100644
index 0000000..f949bfe
--- /dev/null
+++ b/tests/gui/test_sfp_debug_polling.py
@@ -0,0 +1,28 @@
+import pytest
+
+from target_simulator.gui import sfp_debug_window
+
+
+def test_sfpdebugwindow_starts_polling(monkeypatch):
+    calls = []
+
+    # Replace the after method on the class to capture scheduling attempts
+    def fake_after(self, ms, callback):
+        calls.append((ms, callback))
+        return "fake_after_id"
+
+    monkeypatch.setattr(
+        sfp_debug_window.SfpDebugWindow, "after", fake_after, raising=False
+    )
+
+    # Instantiate the window (should call after in __init__)
+    w = sfp_debug_window.SfpDebugWindow(master=None)
+
+    # Ensure at least one scheduling call was made
+    assert calls, "SfpDebugWindow did not schedule the polling loop via after()"
+
+    # Verify that one of the calls uses the configured GUI_POLL_INTERVAL_MS
+    assert any(ms == w.GUI_POLL_INTERVAL_MS for ms, _ in calls)
+
+    # Verify that the callback scheduled is the internal _process_latest_payloads method
+    assert any(cb == w._process_latest_payloads for _, cb in calls)