def _cmd(self, command, byte0=None, byte1=None):
std_cmd = True
# Set the first two command bytes; use defaults in most cases
if not byte0:
std_cmd = False
byte0 = self.byte0
if not byte1:
std_cmd = False
byte1 = self.byte1
# Convery first two bytes to hex
if isinstance(byte0, int): byte0 = hex(byte0)[2:].zfill(2)
if isinstance(byte1, int): byte1 = hex(byte1)[2:].zfill(2)
cmd = [byte0, byte1]
# Each command has a category code.
code = command[0]
if isinstance(code, int): code = hex(code)[2:].zfill(2)
# Each command has a length (of its data) associated with it.
# N.B. this length INCLUDES the checksum value!
length = command[1]
if isinstance(length, int): length = hex(length)[2:].zfill(2)
required_length = int(length, 16)
# Add the category code and length to the command
cmd.extend([code, length])
# The actual command data. Include the checksum for length calculation
data = command[2:]
newdata = []
for d in data:
if isinstance(d, int):
d = hex(d)[2:].zfill(2)
newdata.append(d)
data = newdata
data_length = len(data) + 1
# If issuing TV commands and the lengths don't match, zero-pad value
if std_cmd and data_length != required_length:
missing_data_length = required_length - data_length
zero_pad = ['00' for x in range(missing_data_length)]
data = zero_pad + data
# Add the data to the command
cmd.extend(data)
# Calculate the checksum and add it to the command
checksum = self._chksum(cmd)
cmd.append(checksum)
# Add a carriage return? Required? Probably not.
#cmd.append('0D')
# Uncomment for debugging; what is the whole command?
#print "FINAL COMMAND:", cmd
# Hex-encode the command for transmission
try:
enccmd = hexencode(''.join(cmd))
except TypeError:
raise EncodeError("Cannot encode command: '%s'" % command)
# Write the command to the serial port connection
self.__conn.write(enccmd)
self.__conn.flushOutput()
# Command responses are always going to be 3 (hex) bytes:
# 0x70 (header), 0xXX (response code), 0xXX (checksum)
response = self.__conn.read(6)
# Wait longer to read the response if nothing was returned
if len(response) is 0:
#self.__conn.timeout = 0.1
response = self.__conn.read(3)
#self.__conn.timeout = self.command_interval
# Zero-length responses are an error
if len(response) is 0:
raise ResponseError("No response received for command '%s'" % cmd)
# Decode the hexadecimal response
dec_response = hexdecode(response)
# Extract the response (discard header and checksum)
try:
response_code = self._nsplit(dec_response)[1]
except IndexError:
raise ResponseError("Garbled response: '%s'" % response)
# Raise exceptions if abnormal termination
if response_code == '01':
raise LimitOverError("Value overrun (exceeds maximum limit)")
elif response_code == '02':
raise LimitUnderError("Value underrun (below minimum limit)")
elif response_code == '03':
raise CommandCancelled("Invalid data/length (command cancelled)")
elif response_code == '04':
raise ParseError("Invalid command (parser error)")
return response_code
def parse(self, elt, ps):
val = String.parse(self, elt, ps)
return hexdecode(val)
def _cmd(self, command, byte0=None, byte1=None):
std_cmd = True
# Set the first two command bytes; use defaults in most cases
if not byte0:
std_cmd = False
byte0 = self.byte0
if not byte1:
std_cmd = False
byte1 = self.byte1
# Convert first two bytes to hex
if isinstance(byte0, int):
byte0 = hex(byte0)[2:].zfill(2)
if isinstance(byte1, int):
byte1 = hex(byte1)[2:].zfill(2)
cmd = [byte0, byte1]
# Each command has a category code.
code = command[0]
if isinstance(code, int):
code = hex(code)[2:].zfill(2)
# Each command has a length (of its data) associated with it.
# N.B. this length INCLUDES the checksum value!
length = command[1]
if isinstance(length, int):
length = hex(length)[2:].zfill(2)
required_length = int(length, 16)
# Add the category code and length to the command
cmd.extend([code, length])
# The actual command data. Include the checksum for length calculation
data = command[2:]
newdata = []
for d in data:
if isinstance(d, int):
d = hex(d)[2:].zfill(2)
newdata.append(d)
data = newdata
data_length = len(data) + 1
# If issuing TV commands and the lengths don't match, zero-pad value
if std_cmd and data_length != required_length:
missing_data_length = required_length - data_length
zero_pad = ['00' for x in range(missing_data_length)]
data = zero_pad + data
# Add the data to the command
cmd.extend(data)
# Calculate the checksum and add it to the command
checksum = self._chksum(cmd)
cmd.append(checksum)
# Add a carriage return? Required? Probably not.
# cmd.append('0D')
# Hex-encode the command for transmission
try:
enccmd = hexencode(''.join(cmd))
except TypeError:
raise EncodeError("Cannot encode command: '%s'" % command)
# Write the command to the serial port connection
self.__conn.write(enccmd)
self.__conn.flushOutput()
# Command responses are always going to be 3 (hex) bytes:
# 0x70 (header), 0xXX (response code), 0xXX (checksum)
response = self.__conn.read(6)
# Wait longer to read the response if nothing was returned
if len(response) is 0:
# self.__conn.timeout = 0.1
response = self.__conn.read(3)
# self.__conn.timeout = self.command_interval
# Zero-length responses are an error
if len(response) is 0:
raise ResponseError("No response received for command '%s'" % cmd)
# Decode the hexadecimal response
dec_response = hexdecode(response)
# Extract the response (discard header and checksum)
try:
response_code = self._nsplit(dec_response)[1]
response_int = int(response_code, 16)
except IndexError:
raise ResponseError("Garbled response: '%s'" % response)
# Raise exceptions if abnormal termination
if response_int == 1:
raise LimitOverError("Value overrun (exceeds maximum limit)")
elif response_int == 2:
raise LimitUnderError("Value underrun (below minimum limit)")
elif response_int == 3:
raise CommandCancelled("Invalid data/length (command cancelled)")
elif response_int == 4:
raise ParseError("Invalid command (parser error)")
return response_int
