def test_init_by_name_matrix_style(self):
"""Test symbol creation when it's an array denoted as matrix
This is how an array originating from Simulink could look like.
"""
var = PLCVariable(
"ArrayVar",
ads_type=0,
symbol_type="matrix_21_int8_T", # Simulink array looks like this
)
var.plc_type = constants.PLCTYPE_ARR_SINT(21) # Have to do this
# manually
var.index_group = 123
var.index_offset = 100
self.handler.add_variable(var)
self.plc.open()
symbol = AdsSymbol(
self.plc,
name=var.name,
index_group=var.index_group,
index_offset=var.index_offset,
symbol_type=var.symbol_type,
) # No lookup
# Verify looked up info
self.assertEqual(var.plc_type, symbol.plc_type)
self.assertEqual(var.symbol_type, symbol.symbol_type)
self.assertAdsRequestsCount(0) # No requests
def test_init_invalid_type(self):
"""Test symbol lookup when type cannot be found
There was a read/write check that verifies the plc_typ was not None,
but this was removed.
"""
var = PLCVariable(name="UnknownType",
ads_type=0,
symbol_type="non_existent_type")
var.index_group = 123
var.index_offset = 100
var.plc_type = constants.PLCTYPE_BYTE # Set to something real
self.handler.add_variable(var)
with self.plc:
# Create symbol while providing everything:
symbol = AdsSymbol(self.plc, name=var.name)
self.assertEqual(var.symbol_type, symbol.symbol_type)
self.assertIsNone(symbol.plc_type)
# with self.assertRaises(ValueError) as cm:
# # Without type specified, it cannot read
# symbol.read()
# self.assertIn('Cannot read or write', str(cm.exception))
with self.assertRaises(TypeError) as cm:
# Error is thrown inside pyads_ex
symbol.read()
self.assertIn("NoneType", str(cm.exception))
self.assertAdsRequestsCount(1) # Only a WRITE followed by a READ
def test_write_structure_array(self):
"""Test symbol value reading with structures."""
structure_def = (("a", pyads.PLCTYPE_INT, 1), ("b", pyads.PLCTYPE_INT,
1),
("s", pyads.PLCTYPE_STRING, 1))
values = [{"a": 1, "b": 2, "s": "foo"}, {"a": 3, "b": 4, "s": "bar"}]
data = bytes(bytes_from_dict(values, structure_def))
self.handler.add_variable(
PLCVariable("TestStructure",
data,
constants.ADST_VOID,
symbol_type="TestStructure"))
write_values = [{
"a": 42,
"b": 43,
"s": "hello"
}, {
"a": 44,
"b": 45,
"s": "world"
}]
with self.plc:
symbol = self.plc.get_symbol("TestStructure",
structure_def=structure_def,
array_size=2)
symbol.write(write_values)
read_values = symbol.read()
self.assertEqual(write_values, read_values)
def test_init_by_name_matrix_style(self):
"""Test symbol creation when it's an array denoted as matrix
This is how an array originating from Simulink could look like.
"""
var = PLCVariable(
"ArrayVar",
struct.pack("<21b", *range(21)),
ads_type=constants.ADST_VOID,
symbol_type="matrix_21_int8_T", # Simulink array looks like this
index_group=123,
index_offset=100,
)
self.handler.add_variable(var)
self.plc.open()
symbol = AdsSymbol(
self.plc,
name=var.name,
index_group=var.index_group,
index_offset=var.index_offset,
symbol_type=var.symbol_type, # String initialization
) # No lookup
# Verify looked up info
self.assertEqual(constants.PLCTYPE_ARR_SINT(21), symbol.plc_type)
self.assertEqual(var.symbol_type, symbol.symbol_type)
self.assertAdsRequestsCount(0) # No requests
def test_init_by_name_array(self):
"""Test symbol creation when it's an array"""
var = PLCVariable(
"ArrayVar",
ads_type=constants.ADST_INT16, # dataType does not represent
# array unfortunately
symbol_type="ARRAY [1..5] OF INT", # Array looks like this in PLC
)
var.plc_type = constants.PLCTYPE_ARR_INT(5) # Have to do this
# manually
self.handler.add_variable(var)
self.plc.open()
symbol = AdsSymbol(self.plc, name=var.name)
# Verify looked up info
self.assertEqual(var.name, symbol.name)
self.assertEqual(var.index_group, symbol.index_group)
self.assertEqual(var.index_offset, symbol.index_offset)
self.assertEqual(var.plc_type, symbol.plc_type)
self.assertEqual(var.symbol_type, symbol.symbol_type)
self.assertIsNone(symbol.comment)
my_list = symbol.read()
self.assertIsInstance(my_list, list)
self.assertEqual(5, len(my_list))
my_list[4] = 420
symbol.write(my_list) # Modify array
my_list2 = symbol.read() # Read again
self.assertEqual(my_list, my_list2)
self.assertAdsRequestsCount(4) # A READWRITE (for info), READ,
def test_string(self):
"""Test symbol with a string value"""
variable = PLCVariable("my_text",
bytes(50),
ads_type=constants.ADST_STRING,
symbol_type="STRING(50)")
self.handler.add_variable(variable)
with self.plc:
symbol = self.plc.get_symbol("my_text")
symbol.write("I am a string!")
value = symbol.read()
self.assertEqual(value, "I am a string!")
def setUp(self):
# type: () -> None
"""Establish connection to the test server."""
# Clear test server and handler
self.test_server.request_history = []
self.handler.reset()
# Create PLC variable that is added by default
self.test_var = PLCVariable("TestDouble",
ads_type=constants.ADST_REAL64,
symbol_type="LREAL")
self.test_var.comment = "Some variable of type double"
self.handler.add_variable(self.test_var)
self.plc = pyads.Connection(TEST_SERVER_AMS_NET_ID,
TEST_SERVER_AMS_PORT,
TEST_SERVER_IP_ADDRESS)
def test_read_structure(self):
"""Test symbol value reading with structures."""
structure_def = (
("i", pyads.PLCTYPE_INT, 1),
("s", pyads.PLCTYPE_STRING, 1),
)
values = {"i": 1, "s": "foo"}
data = bytes(bytes_from_dict(values, structure_def))
self.handler.add_variable(
PLCVariable("TestStructure",
data,
constants.ADST_VOID,
symbol_type="TestStructure"))
with self.plc:
symbol = self.plc.get_symbol("TestStructure",
structure_def=structure_def)
read_values = symbol.read()
self.assertEqual(values, read_values)
def test_init_invalid_type(self):
"""Test symbol lookup when type cannot be found
There was a read/write check that verifies the plc_typ was not None,
but this was removed.
"""
var = PLCVariable("UnknownType",
b"\x00",
ads_type=constants.ADST_VOID,
symbol_type="non_existent_type",
index_group=123,
index_offset=100)
self.handler.add_variable(var)
with self.plc:
# Create symbol while providing everything:
symbol = AdsSymbol(self.plc, name=var.name)
self.assertEqual(var.symbol_type, symbol.symbol_type)
with self.assertRaises(TypeError) as cm:
# Error is thrown inside pyads_ex
symbol.read()
self.assertIn("NoneType", str(cm.exception))
self.assertAdsRequestsCount(1) # Only a WRITE followed by a READ
