def get_request(self, protocol=None):
"""
:param protocol: the supported protocol
:return:
"""
# sets self[KEY_REQ_RAW] and self[KEY_REQ_PROTOCOL]
super().get_request(protocol)
if protocol is None:
# will throw exception, if neither DST or SRC set
protocol = self.get_protocol()
if protocol == transaction.IA_PROTOCOL_MBASC:
result = self._mbasc_get_request()
elif protocol == transaction.IA_PROTOCOL_MBRTU:
result = self._mbrtu_get_request()
elif protocol == transaction.IA_PROTOCOL_MBTCP:
result = self._mbtcp_get_request()
else:
raise transaction.IaBadProtocol(
"Unknown IA Protocol:{}".format(protocol))
return result
def set_response(self, data, protocol=None):
"""
:param bytes data:
:param protocol: the supported protocol
:return:
"""
# sets self[KEY_REQ_RAW] and self[KEY_REQ_PROTOCOL]
super().set_response(data, protocol)
if protocol == transaction.IA_PROTOCOL_MBASC:
result = self._mbasc_set_response(data)
max_data = 252
elif protocol == transaction.IA_PROTOCOL_MBRTU:
result = self._mbrtu_set_response(data)
max_data = 252
elif protocol == transaction.IA_PROTOCOL_MBTCP:
result = self._mbtcp_set_response(data)
max_data = 255
else:
raise transaction.IaBadProtocol(
"Unknown IA Protocol:{}".format(protocol))
if len(self[self.KEY_RSP]) > max_data:
raise ModbusBadForm(
"data length () is too long".format(len(self[self.KEY_RSP])))
return result
def get_no_response_error(self, protocol=None):
"""
return the correct response for a time-out/no answer
:param protocol: the supported protocol
:return:
"""
# super().get_response(protocol)
if protocol is None:
# will throw exception, if neither DST or SRC set
protocol = self.get_protocol()
if protocol == transaction.IA_PROTOCOL_MBASC:
# Modbus/ASCII returns nothing
result = None
elif protocol == transaction.IA_PROTOCOL_MBRTU:
# Modbus/RTU returns nothing
result = None
elif protocol == transaction.IA_PROTOCOL_MBTCP:
# Modbus/TCP, we want the exception 0x0B, so in effect create a
# 'fake' self[self.KEY_RSP]
# start with the command, set the MSB and append the err code
value = [self[self.KEY_REQ][0] | 0x80, 0x0B]
self[self.KEY_RSP] = bytes(value)
result = self._mbtcp_get_response()
else:
raise transaction.IaBadProtocol(
"Unknown IA Protocol:{}".format(protocol))
return result