def testBuildRequest(self):
"""Test the string returned by building a request"""
query = modbus_rtu.RtuQuery()
request = query.build_request(to_data(""), 0)
expected = struct.pack(">B", 0)
expected_crc = crc16_alternative(expected)
expected += struct.pack(">H", expected_crc)
self.assertEqual(expected, request)
def testBuildRequestWithSlave(self):
"""Test the string returned by building a request with a slave"""
query = modbus_rtu.RtuQuery()
for i in range(0, 256):
request = query.build_request(to_data(""), i)
expected = struct.pack(">B", i)
expected_crc = crc16_alternative(expected)
expected += struct.pack(">H", expected_crc)
self.assertEqual(expected, request)
def testParseWrongCrcResponse(self):
"""Test an error is raised if wrong transaction id"""
query = modbus_rtu.RtuQuery()
pdu = to_data("a")
request = query.build_request(pdu, 5)
response = struct.pack(">B" + str(len(pdu)) + "s", 5, pdu)
response_crc = crc16_alternative(response)+1
response += struct.pack(">H", response_crc)
self.assertRaises(modbus_tk.modbus.ModbusInvalidResponseError, query.parse_response, response)
def testBuildResponse(self):
"""Test that the response of an request is build properly"""
query = modbus_rtu.RtuQuery()
i = 0
for pdu in ["", "a", "a" * 127, "abcdefghi"]:
request = query.build_request(to_data(pdu), i)
response = query.build_response(to_data(pdu))
response_pdu = query.parse_response(response)
self.assertEqual(to_data(pdu), response_pdu)
i += 1
def testParseRequest(self):
"""Test that Modbus Rtu part of the request is understood"""
query = modbus_rtu.RtuQuery()
i = 0
for pdu in ["", "a", "a" * 127, "abcdefghi"]:
request = query.build_request(to_data(pdu), i)
(slave, extracted_pdu) = query.parse_request(request)
self.assertEqual(extracted_pdu, to_data(pdu))
self.assertEqual(slave, i)
i += 1
def testParseWrongSlaveResponse(self):
"""Test an error is raised if the slave id is wrong"""
query = modbus_rtu.RtuQuery()
pdu = "a"
request = query.build_request(pdu, 5)
response = struct.pack(">B" + str(len(pdu)) + "s", 8, pdu)
response_crc = crc16_alternative(response)
response += struct.pack(">H", response_crc)
self.assertRaises(modbus_tk.modbus.ModbusInvalidResponseError,
query.parse_response, response)
def testBuildRequestWithPdu(self):
"""Test the request returned by building a request with a pdu"""
query = modbus_rtu.RtuQuery()
for i in xrange(247):
for pdu in ["", "a", "a" * 127, "abcdefghi"]:
request = query.build_request(pdu, i)
expected = struct.pack(">B" + str(len(pdu)) + "s", i, pdu)
expected_crc = crc16_alternative(expected)
expected += struct.pack(">H", expected_crc)
self.assertEqual(expected, request)
def testParseRespone(self):
"""Test that Modbus Rtu part of the response is understood"""
query = modbus_rtu.RtuQuery()
for i in xrange(247):
for pdu in ["", "a", "a" * 127, "abcdefghi"]:
request = query.build_request("a", i)
response = struct.pack(">B" + str(len(pdu)) + "s", i, pdu)
response_crc = crc16_alternative(response)
response += struct.pack(">H", response_crc)
extracted = query.parse_response(response)
self.assertEqual(extracted, pdu)
def testParseTooShortRequest(self):
"""Test an error is raised if the request is too short"""
query = modbus_rtu.RtuQuery()
for i in range(3):
self.assertRaises(modbus_tk.modbus.ModbusInvalidRequestError,
query.parse_request, to_data("a" * i))
def testParseTooShortRespone(self):
"""Test an error is raised if the response is too short"""
query = modbus_rtu.RtuQuery()
for i in range(3):
self.assertRaises(modbus_tk.modbus.ModbusInvalidResponseError,
query.parse_response, "a" * i)
def testBuildRequestWithInvalidSlave(self):
"""Test that an error is raised when invalid slave is passed"""
query = modbus_rtu.RtuQuery()
for i in ([256, -1, 312, 3541, 65536, 65656]):
self.assertRaises(modbus_tk.modbus.InvalidArgumentError,
query.build_request, "", i)
