def parseBuffer(msg):
if len(msg) == 1 and msg[0] == 0x06:
#print("0x06 ACK from HP")
return ()
cmd = msg[3]
datalen = int(msg[4])
data = msg[5:5 + datalen]
crc = msg[5 + datalen]
#mysteryByte = msg[6+datalen]
calcCrc = ChecksumXor8()
calcCrc.process(msg[1:datalen + 6 - 1])
if calcCrc.final() != crc: print("CRC failed for 0x" + msg.hex())
handleFrame(cmd, data)
def getReadRequest(register):
# 0xc0: not a clue
# 0x69: command? (read request)
# command length
# register byte1
# register byte 2
# checksum
msg = bytes([0xc0, 0x69, 0x02])
msg += register.to_bytes(2, "little")
calcCrc = ChecksumXor8()
calcCrc.process(msg)
msg += calcCrc.finalbytes()
print("Generated READ request for ", register,":", msg.hex() )
return(msg)
def getWriteRequest(register, value):
registerDefinition = definition[register]
mode = registerDefinition[9]
if mode != "R/W": return(bytes())
msg = bytes([0xc0, 0x6b, 0x06])
msg += register.to_bytes(2, "little")
factor = int( registerDefinition[5] )
dataType = registerDefinition[4]
signed = { "u8":False, "s8":True, "u16":False, "s16":True, "u32":False, "s32":True }
msg += (value*factor).to_bytes(4, "little", signed=signed[dataType])
calcCrc = ChecksumXor8()
calcCrc.process(msg)
msg += calcCrc.finalbytes()
print("Generated WRITE request for ", register,"<-",value,":", msg.hex() )
return(msg)
def parseBuffer(self, msg):
# while len(self.buf) >= 6: #at least 6 bytes
# if self.buf[0:3] != bytes([0x5c, 0x00, 0x20]): # start message
# print("Skipping spurious bytes: ", self.buf[0:3].hex()) ## this should not happen!!!
# self.buf = self.buf[ 3:len(self.buf) ]
# continue
cmd = msg[3]
datalen = int(msg[4])
# if len(self.buf) < datalen + 6:
# print("Wait until buffer fills..")
# break #incomplete message, wait until buffer fills
data = msg[5:5+datalen]
crc = msg[ 5+datalen ]
mysteryByte = msg[6+datalen]
calcCrc = ChecksumXor8()
calcCrc.process(msg[1:datalen+6-1])
# print("Frame received ", msg.hex(), " length ", len(msg),": calcCrc=", calcCrc.finalhex() )
if calcCrc.final() != crc: print("CRC failed")
self.handleFrame(cmd, data)
def readPosition(numberReps, updateRate=0.2):
data = bytearray.fromhex("5042")
data.append(ChecksumXor8.calc(data))
print('Attempting to make ', numberReps,
' read attemps with intervall of ', updateRate, ' seconds')
try:
ser.open()
except Exception as e:
print("error open serial port: " + str(e))
exit()
if ser.isOpen():
try:
ser.flushInput() #flush input buffer, discarding all its contents
ser.flushOutput() #flush output buffer, aborting current output
# ser.write(data)
# time.sleep(0.010) #give the serial port sometime to receive the data
numOfLines = 1
while True:
ser.write(data)
time.sleep(0.01)
response = ser.read(7)
print('>> Cycle #' + str(numOfLines))
print('Response raw:', binascii.hexlify(response))
position = int.from_bytes(response[2:6], 'big', signed=False)
print('Absolute Position 32bit unsigned:', position)
print('>> End cycle')
numOfLines = numOfLines + 1
time.sleep(updateRate)
if (numOfLines >= numberReps + 1):
break
ser.close()
print('>> Finished reading')
except Exception as e1:
print("error communicating...: " + str(e1))
else:
print("cannot open serial port ")
readPosition(10, 0.2)
#
# Manual Mode
#
# Enter adress of encoder: 40 is default, FF is broadcast - current encoder: 50
adr = bytearray.fromhex("FF")
# Enter command as per list of hiperface commands (52 is status, 42 read position)
# See hiperface spec for details
# # https://cdn.sick.com/media/docs/5/65/865/operating_instructions_specification_hiperface%C2%AE_motor_feedback_protocol_en_im0064865.pdf
cmd = bytearray.fromhex("52")
# Enter masterdata if required (code, register requests), otherwise leave empty
masterData = bytearray.fromhex("")
data = adr + cmd + masterData
data.append(ChecksumXor8.calc(data))
# Enter the number of payload bytes you expect
# value is increased by 3 to account for adress, command ACK and checksum
readNumberOfBytes = 4
readNumberOfBytes += 3
# Sleep time before response is read
sleepTime = 0.01
try:
ser.open()
except Exception as e:
print("error open serial port: " + str(e))
exit()
if ser.isOpen():
try:
ser.flushInput() #flush input buffer, discarding all its contents