def func_wrapper(*args, **kwargs):
try:
return func(*args, **kwargs)
except Snap7Exception as e:
# Function refused by inverter/CPU.
s7_refused = 'CLI : function refused by CPU (Unknown error)'
# Could not reach the device via TCP.
s7_unreach = ' TCP : Unreachable peer'
if e.message == s7_refused:
text = """Write/Read Error : Request for inverter was refused!
Check:
- Parameter number exists? See inverter list manual.
- The index specified exists in the inverter?
- See arguments used for any possible incorrect use.
- Are you trying to write a parameter with
special conditions? e.g., trying to change P0304
with P0010 = 0, or writing a parameter to a telegram
value that it's not in the current telegram (P0922)?
"""
raise Snap7Exception(text)
elif e.message == s7_unreach:
text = """Connection Error : Inverter could not be reached!
Check:
- The IP Address argument is correct?
Is it possible to ping the inverter?
- For G120, make sure the FW is >= version 4.7
(internal versional, r0018, should start with 47).
"""
raise Snap7Exception(text)
else:
raise Snap7Exception(e.message)
return None
def list_blocks_of_type(self, blocktype, size):
"""This function returns the AG list of a specified block type."""
blocktype = snap7.snap7types.block_types.get(blocktype)
if not blocktype:
raise Snap7Exception("The blocktype parameter was invalid")
logger.debug("listing blocks of type: %s size: %s" %
(blocktype, size))
if (size == 0):
return 0
data = (c_uint16 * size)()
count = c_int(size)
result = self.library.Cli_ListBlocksOfType(
self.pointer, blocktype,
byref(data),
byref(count))
logger.debug("number of items found: %s" % count)
check_error(result, context="client")
return data
def __init__(self, lib_location=None):
if self.cdll:
return
self.lib_location = lib_location or self.lib_location or 'libsnap7.so'
if not self.lib_location:
msg = "can't find snap7 library. If installed, try running ldconfig"
raise Snap7Exception(msg)
self.cdll = cdll.LoadLibrary(self.lib_location)
def check_error(code, context="client"):
"""
check if the error code is set. If so, a Python log message is generated
and an error is raised.
"""
if code:
error = error_text(code, context)
logger.error(error)
raise Snap7Exception(error)
def set_connection_type(self, connection_type):
"""
Sets the connection resource type, i.e the way in which the Clients
connects to a PLC.
:param connection_type: 1 for PG, 2 for OP, 3 to 10 for S7 Basic
"""
result = self.library.Cli_SetConnectionType(self.pointer,
c_uint16(connection_type))
if result != 0:
raise Snap7Exception("The parameter was invalid")
def __init__(self, lib_location=None):
if self.cdll:
return
self.lib_location = lib_location or self.lib_location or find_library(
'snap7')
if not self.lib_location:
msg = "can't find snap7 library. If installed, try running ldconfig"
self.lib_location = GetSnap7Dll()
print self.lib_location
#print self.lib_location
if not os.path.isfile(self.lib_location):
raise Snap7Exception(msg)
self.cdll = cdll.LoadLibrary(self.lib_location)
def set_connection_params(self, address, local_tsap, remote_tsap):
"""
Sets internally (IP, LocalTSAP, RemoteTSAP) Coordinates.
This function must be called just before Cli_Connect().
:param address: PLC/Equipment IPV4 Address, for example "192.168.1.12"
:param local_tsap: Local TSAP (PC TSAP)
:param remote_tsap: Remote TSAP (PLC TSAP)
"""
assert re.match(ipv4, address), '%s is invalid ipv4' % address
result = self.library.Cli_SetConnectionParams(self.pointer, address,
c_uint16(local_tsap),
c_uint16(remote_tsap))
if result != 0:
raise Snap7Exception("The parameter was invalid")
def set_connection_params(self, ip_address, tsap_snap7, tsap_logo):
"""
Sets internally (IP, LocalTSAP, RemoteTSAP) Coordinates.
This function must be called just before Cli_Connect().
:param ip_address: IP ip_address of server
:param tsap_snap7: TSAP SNAP7 Client (e.g. 10.00 = 0x1000)
:param tsap_logo: TSAP Logo Server (e.g. 20.00 = 0x2000)
"""
assert re.match(ipv4, ip_address), '%s is invalid ipv4' % ip_address
result = self.library.Cli_SetConnectionParams(self.pointer, ip_address,
c_uint16(tsap_snap7),
c_uint16(tsap_logo))
if result != 0:
raise Snap7Exception("The parameter was invalid")
def get_cpu_state(self):
"""
Retrieves CPU state from client
"""
state = c_int(0)
self.library.Cli_GetPlcStatus(self.pointer, byref(state))
try:
status_string = cpu_statuses[state.value]
except KeyError:
status_string = None
if not status_string:
raise Snap7Exception("The cpu state (%s) is invalid" % state.value)
logging.debug("CPU state is %s" % status_string)
return status_string
def get_block_info(self, blocktype, db_number):
"""Returns the block information for the specified block."""
blocktype = snap7.snap7types.block_types.get(blocktype)
if not blocktype:
raise Snap7Exception("The blocktype parameter was invalid")
logging.debug("retrieving block info for block %s of type %s" %
(db_number, blocktype))
data = TS7BlockInfo()
result = self.library.Cli_GetAgBlockInfo(self.pointer, blocktype,
db_number, byref(data))
check_error(result, context="client")
return data
def check_as_b_send_completion(self):
"""
Checks if the current asynchronous send job was completed and terminates
immediately.
"""
op_result = ctypes.c_int32()
result = self.library.Par_CheckAsBSendCompletion(
self.pointer, ctypes.byref(op_result))
return_values = {
0: "job complete",
1: "job in progress",
-2: "invalid handled supplied",
}
if result == -2:
raise Snap7Exception("The Client parameter was invalid")
return return_values[result], op_result
