diff --git a/biogascontrollerapp/lib/test/com.py b/biogascontrollerapp/lib/test/com.py
index b6a0d65..8f30ac6 100644
--- a/biogascontrollerapp/lib/test/com.py
+++ b/biogascontrollerapp/lib/test/com.py
@@ -7,6 +7,7 @@ from typing import Optional
 import queue
 import random
 import serial
+import time
 
 from lib.com import ComSuperClass
 
@@ -17,23 +18,28 @@ from lib.com import ComSuperClass
 
 # All double __ prefixed properties and methods are not available in the actual one
 
-instruction_lut = {
-    "PR": "\nPR\n",
-    "PT": "\nPT\n",
-    "RD": "\nRD\n",
-    "NM": "\nNM\n",
-    "FM": "\nFM\n",
+instruction_lut: dict[str, list[str]] = {
+    "PR": ["\n", "P", "R", "\n"],
+    "PT": ["\n", "P", "T", "\n"],
+    "RD": ["\n", "R", "D", "\n"],
+    "NM": ["\n", "N", "M", "\n"],
+    "FM": ["\n", "F", "M", "\n"],
 }
 
 
+class SimulationError(Exception):
+    pass
+
+
 class Com(ComSuperClass):
     def __init__(self, baudrate: int = 19200, filters: Optional[list[str]] = None) -> None:
         # Calling the constructor of the super class to assign defaults
-        print("WARNING: Using testing library for communication!")
+        print("\n\nWARNING: Using testing library for communication!\n\n")
         super().__init__(baudrate, filters);
 
         # Initialize queue with values to be sent on call of recieve
         self.__simulated_data: queue.Queue[int] = queue.Queue()
+        self.__simulated_data_remaining = 0
 
         # Keep track of the number of bytes sent to fulfil protocol
         self.__bytes_sent: int = 0
@@ -62,19 +68,35 @@ class Com(ComSuperClass):
         pass
 
     def receive(self, byte_count: int) -> bytes:
-        # TODO: Make it return simulated data
+        # TODO: Make it return simulated data -> Refill if queue length is smaller than requested byte_count
         data = []
+        # If queue is too short, refill it
+        if self.__simulated_data_remaining < byte_count:
+            self.__fill_queue()
+
         for i in range(byte_count):
-            data.append(self.__simulated_data.get_nowait())
-        return bytes("A", "ascii")
+            if self.__mode == "NM":
+                time.sleep( 0.001 );
+            try:
+                data.append(self.__simulated_data.get_nowait())
+            except Exception as e:
+                print("ERROR: Simulation could not continue")
+                raise SimulationError("Simulation encountered an error with the simulation queue. The error encountered: \n" + str(e))
+        return bytes(data)
 
     def send(self, msg: str) -> None:
         # TODO: Use LUT to find what should be added to the queue for read
         # Using LUT to reference
-        pass
+        readback = instruction_lut.get(msg)
+        if readback != None:
+            for i in range(len(readback)):
+                self.__simulated_data.put(ord(readback[i]))
 
     def send_float(self, msg: float) -> None:
         pass
 
-    def __generate_random_value(self, precision: int) -> bytes:
-        return bytes(str(round(random.random() * precision) / precision), "ascii")
+    def __add_random_float(self):
+        pass
+
+    def __fill_queue(self):
+        pass