diff --git a/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/CMakeLists.txt b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/CMakeLists.txt
index bcea790..c58978b 100644
--- a/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/CMakeLists.txt
+++ b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/CMakeLists.txt
@@ -222,7 +222,12 @@ set(msg_files
 	Wind.msg
 	YawEstimatorStatus.msg
 	SimulinkCustomMessage.msg
-	PlcHoldingRegisters.msg
+	PlcDiscreteInputs.msg
+	PlcInputRegisters.msg
+	PlcCoilsRead.msg
+	PlcCoilsWrite.msg
+	PlcHoldingRegistersRead.msg
+	PlcHoldingRegistersWrite.msg
 )
 list(SORT msg_files)
 
diff --git a/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcCoilsRead.msg b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcCoilsRead.msg
new file mode 100644
index 0000000..482c638
--- /dev/null
+++ b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcCoilsRead.msg
@@ -0,0 +1,5 @@
+uint64 timestamp              # time since system start (microseconds)
+
+uint16 num_coils = 128        # How many coils can be stored in coil_array
+
+bool[128] coil_array_read     # Array of bools that are read from the PLC
\ No newline at end of file
diff --git a/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcCoilsWrite.msg b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcCoilsWrite.msg
new file mode 100644
index 0000000..93b4bb9
--- /dev/null
+++ b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcCoilsWrite.msg
@@ -0,0 +1,7 @@
+uint64 timestamp              # time since system start (microseconds)
+
+uint16 num_coils = 128        # How many coils can be stored in coil_array
+
+bool[128] coil_array_write    # Array of bools that are used for writing to the PLC
+
+bool written                  # Has the coil_array_write been written yet to the PLC
\ No newline at end of file
diff --git a/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcDiscreteInputs.msg b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcDiscreteInputs.msg
new file mode 100644
index 0000000..88e6aa8
--- /dev/null
+++ b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcDiscreteInputs.msg
@@ -0,0 +1,5 @@
+uint64 timestamp              # time since system start (microseconds)
+
+uint16 num_inputs = 128       # How many inputs can be stored in input_array
+
+bool[128] input_array         # Array of bools
diff --git a/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcHoldingRegistersRead.msg b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcHoldingRegistersRead.msg
new file mode 100644
index 0000000..6c978a1
--- /dev/null
+++ b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcHoldingRegistersRead.msg
@@ -0,0 +1,5 @@
+uint64 timestamp                    # time since system start (microseconds)
+
+uint16 num_registers = 128          # How many registers can be stored in register_array_read
+
+uint16[128] register_array_read     # Array of unsigned, 16 bit registers that are read from the PLC
\ No newline at end of file
diff --git a/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcHoldingRegistersWrite.msg b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcHoldingRegistersWrite.msg
new file mode 100644
index 0000000..1427d1a
--- /dev/null
+++ b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcHoldingRegistersWrite.msg
@@ -0,0 +1,7 @@
+uint64 timestamp                    # time since system start (microseconds)
+
+uint16 num_registers = 128          # How many registers can be stored in register_array_write
+
+uint16[128] register_array_write    # Array of unsigned, 16 bit registers that are used for writing to the PLC
+
+bool written                        # Has the register_array_write been written yet to the PLC
\ No newline at end of file
diff --git a/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcInputRegisters.msg b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcInputRegisters.msg
new file mode 100644
index 0000000..4d74488
--- /dev/null
+++ b/MATLAB/MODBUS_TCP_TESTING/PX4-Autopilot/msg/PlcInputRegisters.msg
@@ -0,0 +1,5 @@
+uint64 timestamp              # time since system start (microseconds)
+
+uint16 num_registers = 128    # How many registers can be stored in register_array
+
+uint16[128] register_array    # Array of unsigned, 16 bit registers