diff --git a/.gitignore b/.gitignore
index ed7e36d..241553b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,7 @@ relPaths.sh
 /doc/
 *_info_positions.req
 *_info_settings.req
+__pycache__/
+*.py[cod]
+*$py.class
+test-reports/
\ No newline at end of file
diff --git a/Makefile b/Makefile
index a484532..077c9f2 100644
--- a/Makefile
+++ b/Makefile
@@ -32,3 +32,7 @@ iocBoot_DEPEND_DIRS += $(filter %App,$(DIRS))
 # Add any additional dependency rules here:
 
 include $(TOP)/configure/RULES_TOP
+
+
+ioctests:
+	.\system_tests\run_tests.bat
diff --git a/system_tests/__init__.py b/system_tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/system_tests/lewis_emulators/__init__.py b/system_tests/lewis_emulators/__init__.py
new file mode 100644
index 0000000..ad92558
--- /dev/null
+++ b/system_tests/lewis_emulators/__init__.py
@@ -0,0 +1,2 @@
+# DO NOT DELETE THIS FILE - LEWIS FRAMEWORK REQUIRES THE DIRECTORY TO BE IMPORTABLE
+from __future__ import absolute_import
diff --git a/system_tests/lewis_emulators/lewis_versions.py b/system_tests/lewis_emulators/lewis_versions.py
new file mode 100644
index 0000000..0f6c45a
--- /dev/null
+++ b/system_tests/lewis_emulators/lewis_versions.py
@@ -0,0 +1,2 @@
+LEWIS_1_3_0 = "1.3.0"
+LEWIS_LATEST = LEWIS_1_3_0
diff --git a/system_tests/lewis_emulators/tti355/__init__.py b/system_tests/lewis_emulators/tti355/__init__.py
new file mode 100644
index 0000000..8318ff0
--- /dev/null
+++ b/system_tests/lewis_emulators/tti355/__init__.py
@@ -0,0 +1,5 @@
+from .device import SimulatedTti355
+from ..lewis_versions import LEWIS_LATEST
+
+framework_version = LEWIS_LATEST
+__all__ = ['SimulatedTti355']
diff --git a/system_tests/lewis_emulators/tti355/device.py b/system_tests/lewis_emulators/tti355/device.py
new file mode 100644
index 0000000..bf0b505
--- /dev/null
+++ b/system_tests/lewis_emulators/tti355/device.py
@@ -0,0 +1,106 @@
+from collections import OrderedDict
+from .states import DefaultState
+from lewis.devices import StateMachineDevice
+from random import random
+
+
+class SimulatedTti355(StateMachineDevice):
+
+    def _initialize_data(self):
+        """
+        Initialize all of the device's attributes.
+        """
+        self.identity = "Thurlby Thandar,EL302P,0,v1.14"
+        self.voltage = 0.00
+        self.voltage_sp = 1.00
+        self.current = 0.00
+        self.current_limit_sp = 1.00
+        self.output_status = "OUT OFF"
+        self.output_mode = "M CV"
+        self.error = "ERR 0"
+        self._max_voltage = 35.0
+        self._max_current = 5.0
+        self.load_resistance = 10
+
+    def reset(self):
+        self._initialize_data()
+
+    def _get_state_handlers(self):
+        return {
+            'default': DefaultState(),
+        }
+
+    def _get_initial_state(self):
+        return 'default'
+
+    def _get_transition_handlers(self):
+        return OrderedDict([
+        ])
+
+    def calculate_potential_current(self, voltage):
+        return voltage/self.load_resistance
+    
+    def calculate_actual_voltage(self):
+        return self.get_current() * self.load_resistance
+    
+    def voltage_within_limits(self, voltage):
+        return voltage <= self._max_voltage
+
+    def get_voltage(self):
+        if self.output_status == "OUT ON":
+            if self.output_mode == "M CI":
+                self.voltage = self.calculate_actual_voltage()
+            else:
+                self.voltage = self.voltage_sp + ((random()-0.5)/1000)
+        else:
+            self.voltage = ((random()-0.5)/1000)
+        return self.voltage
+    
+    def set_voltage_sp(self, voltage):
+        voltage = round(float(voltage), 2)
+        if not self.voltage_within_limits(voltage):
+            self.error = "ERR 2"
+        else:
+            self.voltage_sp = voltage
+            if self.calculate_potential_current(voltage) > self.current_limit_sp and self.output_status == "OUT ON":
+                self.output_mode = "M CI"
+    
+    def current_within_limits(self, current):
+        return current <= self._max_current
+                    
+    def get_current(self):
+        if self.output_status == "OUT ON" and self.output_mode == "M CI":
+            self.current = self.current_limit_sp + ((random()-0.5)/1000)
+        else:
+            self.current = ((random()-0.5)/1000)
+        return self.current
+    
+    def set_current_limit_sp(self, current):
+        current = round(float(current), 2)
+        if not self.current_within_limits(current):
+            self.error = "ERR 2"
+        else:
+            self.current_limit_sp = current
+    
+    def set_output_status(self, status):
+        if status == "ON":
+            self.output_status = "OUT ON"
+        elif status == "OFF":
+            self.output_status = "OUT OFF"
+            self.reset()
+
+    def get_output_status(self):
+        return self.output_status
+
+    def get_output_mode(self):
+        return self.output_mode
+    
+    def get_error_status(self):
+        if self.error == "ERR 1":
+            self.error = "ERR 0"
+            return "ERR 1"
+        elif self.error == "ERR 2":
+            self.error = "ERR 0"
+            return "ERR 2"
+        else:
+            return self.error
diff --git a/system_tests/lewis_emulators/tti355/interfaces/__init__.py b/system_tests/lewis_emulators/tti355/interfaces/__init__.py
new file mode 100644
index 0000000..9323ad2
--- /dev/null
+++ b/system_tests/lewis_emulators/tti355/interfaces/__init__.py
@@ -0,0 +1,3 @@
+from .stream_interface import Tti355StreamInterface
+
+__all__ = ['Tti355StreamInterface']
diff --git a/system_tests/lewis_emulators/tti355/interfaces/stream_interface.py b/system_tests/lewis_emulators/tti355/interfaces/stream_interface.py
new file mode 100644
index 0000000..143d5a7
--- /dev/null
+++ b/system_tests/lewis_emulators/tti355/interfaces/stream_interface.py
@@ -0,0 +1,85 @@
+from lewis.adapters.stream import StreamInterface
+from lewis.utils.command_builder import CmdBuilder
+
+
+class Tti355StreamInterface(StreamInterface):
+
+    in_terminator = "\n"
+    out_terminator = "\r\n"
+       
+    def __init__(self):
+
+        super(Tti355StreamInterface, self).__init__()
+
+        # Commands that we expect via serial during normal operation
+        self.commands = {
+            CmdBuilder(self.get_identity).escape("*IDN?").eos().build(),
+            CmdBuilder(self.reset).escape("*RST").eos().build(),
+            CmdBuilder(self.get_voltage_sp).escape("V?").eos().build(),
+            CmdBuilder(self.set_voltage_sp).escape("V ").float().eos().build(),
+            CmdBuilder(self.get_voltage).escape("VO?").eos().build(),
+
+            CmdBuilder(self.get_current_sp).escape("I?").eos().build(),
+            CmdBuilder(self.set_current_limit_sp).escape("I ").float().eos().build(),
+            CmdBuilder(self.get_current).escape("IO?").eos().build(),
+
+            CmdBuilder(self.get_outputstatus).escape("OUT?").eos().build(),
+            CmdBuilder(self.set_outputstatus_on).escape("ON").eos().build(),
+            CmdBuilder(self.set_outputstatus_off).escape("OFF").eos().build(),
+           
+            CmdBuilder(self.get_output_mode).escape("M?").eos().build(),
+            CmdBuilder(self.get_error_status).escape("ERR?").eos().build(),
+
+        }
+    
+    def handle_error(self, request, error):
+        err_string = "command was: {}, error was: {}: {}\n".format(request, error.__class__.__name__, error)
+        print(err_string)
+        self.log.error(err_string)
+        return err_string
+    
+    def reset(self):
+        self.device.reset()
+        return self.out_terminator
+
+    def get_voltage(self):
+        volt = self.device.get_voltage()
+        return "V{:.2f}".format(volt)
+    
+    def get_voltage_sp(self):
+        return "V{:.2f}".format(self.device.voltage_sp)
+
+    def set_voltage_sp(self, voltage_sp):
+        self.device.set_voltage_sp(float(voltage_sp))
+        return self.out_terminator
+
+    def get_current(self):
+        current = self.device.get_current()
+        return "I{:.2f}".format(current)
+    
+    def get_current_sp(self):
+        return "I{:.2f}".format(self.device.current_limit_sp)
+
+    def set_current_limit_sp(self, current_limit_sp):
+        self.device.set_current_limit_sp(float(current_limit_sp))
+        return self.out_terminator
+
+    def get_outputstatus(self):
+        return self.device.get_output_status()
+
+    def set_outputstatus_on(self):
+        self.device.set_output_status("ON")
+        return self.out_terminator
+
+    def set_outputstatus_off(self):
+        self.device.set_output_status("OFF")
+        return self.out_terminator
+    
+    def get_output_mode(self):
+        return self.device.get_output_mode()
+    
+    def get_error_status(self):
+        return self.device.get_error_status()
+    
+    def get_identity(self):
+        return self.device.identity
diff --git a/system_tests/lewis_emulators/tti355/states.py b/system_tests/lewis_emulators/tti355/states.py
new file mode 100644
index 0000000..e4ca48e
--- /dev/null
+++ b/system_tests/lewis_emulators/tti355/states.py
@@ -0,0 +1,5 @@
+from lewis.core.statemachine import State
+
+
+class DefaultState(State):
+    pass
diff --git a/system_tests/run_tests.bat b/system_tests/run_tests.bat
new file mode 100644
index 0000000..65ab1d6
--- /dev/null
+++ b/system_tests/run_tests.bat
@@ -0,0 +1,10 @@
+@echo off
+setlocal
+REM Run this directory's tests using the IOC Testing Framework
+
+call "%~dp0..\..\..\..\config_env.bat"
+
+REM Command line arguments always passed to the test script
+SET ARGS=--test_and_emulator %~dp0
+call %PYTHON3% -u "%EPICS_KIT_ROOT%\support\IocTestFramework\master\run_tests.py" %ARGS% %*
+IF %ERRORLEVEL% NEQ 0 EXIT /b %ERRORLEVEL%
diff --git a/system_tests/tests/__init__.py b/system_tests/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/system_tests/tests/tti355.py b/system_tests/tests/tti355.py
new file mode 100644
index 0000000..4596634
--- /dev/null
+++ b/system_tests/tests/tti355.py
@@ -0,0 +1,78 @@
+import unittest
+from parameterized import parameterized
+
+from common_tests.tti_common import TtiCommon
+from utils.channel_access import ChannelAccess
+from utils.ioc_launcher import get_default_ioc_dir
+from utils.test_modes import TestModes
+from utils.testing import get_running_lewis_and_ioc, skip_if_recsim
+
+
+DEVICE_PREFIX = "TTI355_01"
+DEVICE_NAME = "tti355"
+
+VOLT_LOW_LIMIT = 0.0
+VOLT_HIGH_LIMIT = 35.0
+CURR_LOW_LIMIT = 0.01
+CURR_HIGH_LIMIT = 5.0
+
+IOCS = [
+    {
+        "name": DEVICE_PREFIX,
+        "directory": get_default_ioc_dir("TTI355"),
+        "macros": {
+            "MIN_VOLT": VOLT_LOW_LIMIT,
+            "MAX_VOLT": VOLT_HIGH_LIMIT,
+            "MIN_CURR": CURR_LOW_LIMIT,
+            "MAX_CURR": CURR_HIGH_LIMIT,
+        },
+        "emulator": DEVICE_NAME,
+    },
+]
+
+
+TEST_MODES = [TestModes.RECSIM, TestModes.DEVSIM]
+
+
+class Tti355Tests(TtiCommon, unittest.TestCase):
+    """
+    Tests for the Tti355 IOC.
+    """
+    def setUp(self):
+        self._lewis, self._ioc = get_running_lewis_and_ioc(DEVICE_NAME, DEVICE_PREFIX)
+        self.ca = ChannelAccess(device_prefix=DEVICE_PREFIX)
+        self._lewis.backdoor_run_function_on_device("reset")
+
+    def get_on_state_name(self):
+        return "ON"
+
+    def get_off_state_name(self):
+        return "OFF"
+
+    @parameterized.expand([
+        ("lt_low_limit", VOLT_LOW_LIMIT-1.0, "low_limit", VOLT_LOW_LIMIT),
+        ("gt_high_limit", VOLT_HIGH_LIMIT+1, "high_limit", VOLT_HIGH_LIMIT)])
+    @skip_if_recsim("Behaviour cannot be simulated in Recsim")
+    def test_WHEN_voltage_setpoint_is_set_outside_max_limits_THEN_setpoint_within(self, case, case_value, limit, limit_value):
+        self.ca.set_pv_value("VOLTAGE:SP", case_value)
+        self.ca.assert_that_pv_is("VOLTAGE:SP", limit_value)
+
+    @parameterized.expand([
+        ("lt_low_limit", CURR_LOW_LIMIT-1, "low_limit", CURR_LOW_LIMIT),
+        ("gt_high_limit", CURR_HIGH_LIMIT+1, "high_limit", CURR_HIGH_LIMIT)])
+    @skip_if_recsim("Behaviour cannot be simulated in Recsim")
+    def test_WHEN_voltage_setpoint_is_set_outside_max_limits_THEN_setpoint_within(self, case, case_value, limit, limit_value):
+        self.ca.set_pv_value("CURRENT:SP", case_value)
+        self.ca.assert_that_pv_is("CURRENT:SP", limit_value)
+
+    @skip_if_recsim("Behaviour cannot be simulated in Recsim")
+    def test_WHEN_identity_requested_THEN_correct_identity_returned(self):
+        expected_identity = "Thurlby Thandar,EL302P,0,v1.14"
+        self.ca.assert_that_pv_is("IDENT", expected_identity)
+
+    @skip_if_recsim("Behaviour cannot be simulated in Recsim")
+    def test_WHEN_ioc_in_error_state_2_THEN_correct_error_state_returned(self):
+        expected_value = "Cmd outside limits"
+        self._lewis.backdoor_set_on_device("error", "ERR 2")
+        self.ca.set_pv_value("ERROR.PROC", 1)
+        self.ca.assert_that_pv_is("ERROR", expected_value)